Fix to ensure Windows uninstaller removes reg entries from the 64 bit registry

2023-01-11 22:39:26 +10:00
2523 changed files with 42441 additions and 78131 deletions
--- a/.editorconfig
+++ b/.editorconfig
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,23 +15,22 @@ jobs:

    steps:
      - name: Clone Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3

      - name: Install .NET 6.0
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v3
        with:
          dotnet-version: '6.0.x'

      - name: Check Code
        run: |
          make check
-          make tests

      - name: Check Mods
        run: |
          sudo apt-get install lua5.1
          make check-scripts
-          make TREAT_WARNINGS_AS_ERRORS=true test
+          make test

  linux-mono:
    name: Linux (mono)
@@ -39,7 +38,7 @@ jobs:

    steps:
      - name: Clone Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3

      - name: Check Code
        run: |
@@ -49,7 +48,7 @@ jobs:
      - name: Check Mods
        run: |
          # check-scripts does not depend on .net/mono, so is not needed here
-          make RUNTIME=mono TREAT_WARNINGS_AS_ERRORS=true test
+          make RUNTIME=mono test

  windows:
    name: Windows (.NET 6.0)
@@ -57,10 +56,10 @@ jobs:

    steps:
      - name: Clone Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3

      - name: Install .NET 6.0
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v3
        with:
          dotnet-version: '6.0.x'

@@ -70,12 +69,12 @@ jobs:
          # Work around runtime failures on the GH Actions runner
          dotnet nuget add source https://api.nuget.org/v3/index.json -n nuget.org
          .\make.ps1 check
-          .\make.ps1 tests
+          dotnet build OpenRA.Test\OpenRA.Test.csproj -c Debug --nologo -p:TargetPlatform=win-x64
+          dotnet test bin\OpenRA.Test.dll --test-adapter-path:.

      - name: Check Mods
        run: |
-          choco install lua --version 5.1.5.52
+          chocolatey install lua --version 5.1.5.52
          $ENV:Path = $ENV:Path + ";C:\Program Files (x86)\Lua\5.1\"
-          $ENV:TREAT_WARNINGS_AS_ERRORS = "true"
          .\make.ps1 check-scripts
          .\make.ps1 test
--- a/.github/workflows/documentation.yml
+++ b/.github/workflows/documentation.yml
@@ -1,9 +1,6 @@
 name: Deploy Documentation

 on:
-  push:
-    branches: [ bleed ]
-    tags: [ 'release-*', 'playtest-*' ]
  workflow_dispatch:
    inputs:
      tag:
@@ -15,49 +12,18 @@ permissions:
  contents: read  #  to fetch code (actions/checkout)

 jobs:
-  prepare:
-    name: Prepare version strings
+  wiki:
+    name: Update Wiki
    if: github.repository == 'openra/openra'
    runs-on: ubuntu-22.04
    steps:
-      - name: Prepare environment variables
-        run: |
-          if [ "${{ github.event_name }}" = "push" ]; then
-            if [ "${{ github.ref_type }}" = "tag" ]; then
-              VERSION_TYPE=`echo "${GITHUB_REF#refs/tags/}" | cut -d"-" -f1`
-              echo "GIT_TAG=${GITHUB_REF#refs/tags/}" >> $GITHUB_ENV
-              echo "VERSION_TYPE=$VERSION_TYPE" >> $GITHUB_ENV
-            else
-              echo "GIT_TAG=bleed" >> $GITHUB_ENV
-              echo "VERSION_TYPE=bleed" >> $GITHUB_ENV
-            fi
-          else
-            VERSION_TYPE=`echo "${{ github.event.inputs.tag }}" | cut -d"-" -f1`
-            echo "GIT_TAG=${{ github.event.inputs.tag }}" >> $GITHUB_ENV
-            echo "VERSION_TYPE=$VERSION_TYPE" >> $GITHUB_ENV
-          fi
-    outputs:
-      git_tag: ${{ env.GIT_TAG }}
-      version_type: ${{ env.VERSION_TYPE }}
-
-  wiki:
-    name: Update Wiki
-    needs: prepare
-    if: github.repository == 'openra/openra' && needs.prepare.outputs.version_type != 'bleed'
-    runs-on: ubuntu-22.04
-    steps:
-      - name: Debug output
-        run: |
-          echo ${{ needs.prepare.outputs.git_tag }}
-          echo ${{ needs.prepare.outputs.version_type }}
-
      - name: Clone Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3
        with:
-          ref: ${{ needs.prepare.outputs.git_tag }}
+          ref: ${{ github.event.inputs.tag }}

      - name: Install .NET 6
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v3
        with:
          dotnet-version: '6.0.x'

@@ -66,53 +32,49 @@ jobs:
          make all

      - name: Clone Wiki
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3
        with:
          repository: openra/openra.wiki
          token: ${{ secrets.DOCS_TOKEN }}
          path: wiki

      - name: Update Wiki (Playtest)
-        if: startsWith(needs.prepare.outputs.git_tag, 'playtest-')
+        if: startsWith(github.event.inputs.tag, 'playtest-')
+        env:
+          GIT_TAG: ${{ github.event.inputs.tag }}
        run: |
-          ./utility.sh all --settings-docs "${{ needs.prepare.outputs.git_tag }}" > "wiki/Settings (playtest).md"
+          ./utility.sh all --settings-docs "${GIT_TAG}" > "wiki/Settings (playtest).md"

      - name: Update Wiki (Release)
-        if: startsWith(needs.prepare.outputs.git_tag, 'release-')
+        if: startsWith(github.event.inputs.tag, 'release-')
+        env:
+          GIT_TAG: ${{ github.event.inputs.tag }}
        run: |
-          ./utility.sh all --settings-docs "${{ needs.prepare.outputs.git_tag }}" > "wiki/Settings.md"
+          ./utility.sh all --settings-docs "${GIT_TAG}" > "wiki/Settings.md"

      - name: Push Wiki
+        env:
+          GIT_TAG: ${{ github.event.inputs.tag }}
        run: |
          cd wiki
          git config --local user.email "actions@github.com"
          git config --local user.name "GitHub Actions"
-          git status
-          git diff-index --quiet HEAD || \
-          (
-            git add --all && \
-            git commit -m "Update auto-generated documentation for ${{ needs.prepare.outputs.git_tag }}" && \
-            git push origin master
-          )
+          git add --all
+          git commit -m "Update auto-generated documentation for ${GIT_TAG}"
+          git push origin master

  docs:
    name: Update docs.openra.net
-    needs: prepare
    if: github.repository == 'openra/openra'
    runs-on: ubuntu-22.04
    steps:
-      - name: Debug output
-        run: |
-          echo ${{ needs.prepare.outputs.git_tag }}
-          echo ${{ needs.prepare.outputs.version_type }}
-
      - name: Clone Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3
        with:
-          ref: ${{ needs.prepare.outputs.git_tag }}
+          ref: ${{ github.event.inputs.tag }}

      - name: Install .NET 6
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v3
        with:
          dotnet-version: '6.0.x'

@@ -120,31 +82,62 @@ jobs:
        run: |
          make all

-      # version_type is release/playtest/bleed - the name of the target branch.
-      - name: Clone docs.openra.net
-        uses: actions/checkout@v4
+      - name: Clone docs.openra.net (Playtest)
+        if: startsWith(github.event.inputs.tag, 'playtest-')
+        uses: actions/checkout@v3
        with:
          repository: openra/docs
          token: ${{ secrets.DOCS_TOKEN }}
          path: docs
-          ref: ${{ needs.prepare.outputs.version_type }}
+          ref: playtest

-      - name: Generate docs files
+      - name: Clone docs.openra.net (Release)
+        if: startsWith(github.event.inputs.tag, 'release-')
+        uses: actions/checkout@v3
+        with:
+          repository: openra/docs
+          token: ${{ secrets.DOCS_TOKEN }}
+          path: docs
+          ref: release
+
+      - name: Update docs.openra.net (Playtest)
+        if: startsWith(github.event.inputs.tag, 'playtest-')
+        env:
+          GIT_TAG: ${{ github.event.inputs.tag }}
        run: |
-          ./utility.sh all --docs "${{ needs.prepare.outputs.git_tag }}" | python3 ./packaging/format-docs.py > "docs/api/traits.md"
-          ./utility.sh all --weapon-docs "${{ needs.prepare.outputs.git_tag }}" | python3 ./packaging/format-docs.py > "docs/api/weapons.md"
-          ./utility.sh all --sprite-sequence-docs "${{ needs.prepare.outputs.git_tag }}" | python3 ./packaging/format-docs.py > "docs/api/sprite-sequences.md"
-          ./utility.sh all --lua-docs "${{ needs.prepare.outputs.git_tag }}" > "docs/api/lua.md"
+          ./utility.sh all --docs "${GIT_TAG}" | python3 ./packaging/format-docs.py > "docs/api/traits.md"
+          ./utility.sh all --weapon-docs "${GIT_TAG}" | python3 ./packaging/format-docs.py > "docs/api/weapons.md"
+          ./utility.sh all --sprite-sequence-docs "${GIT_TAG}" | python3 ./packaging/format-docs.py > "docs/api/sprite-sequences.md"
+          ./utility.sh all --lua-docs "${GIT_TAG}" > "docs/api/lua.md"

-      - name: Update docs.openra.net
+      - name: Update docs.openra.net (Release)
+        if: startsWith(github.event.inputs.tag, 'release-')
+        env:
+          GIT_TAG: ${{ github.event.inputs.tag }}
+        run: |
+          ./utility.sh all --docs "${GIT_TAG}" | python3 ./packaging/format-docs.py > "docs/api/traits.md"
+          ./utility.sh all --weapon-docs "${GIT_TAG}" | python3 ./packaging/format-docs.py > "docs/api/weapons.md"
+          ./utility.sh all --sprite-sequence-docs "${GIT_TAG}" | python3 ./packaging/format-docs.py > "docs/api/sprite-sequences.md"
+          ./utility.sh all --lua-docs "${GIT_TAG}" > "docs/api/lua.md"
+
+      - name: Commit docs.openra.net
+        env:
+          GIT_TAG: ${{ github.event.inputs.tag }}
        run: |
          cd docs
          git config --local user.email "actions@github.com"
          git config --local user.name "GitHub Actions"
-          git status
-          git diff-index --quiet HEAD || \
-          (
-            git add api/*.md && \
-            git commit -m "Update auto-generated documentation for ${{ needs.prepare.outputs.git_tag }}" && \
-            git push origin ${{ needs.prepare.outputs.version_type }}
-          )
+          git add api/*.md
+          git commit -m "Update auto-generated documentation for ${GIT_TAG}"
+
+      - name: Push docs.openra.net (Release)
+        if: startsWith(github.event.inputs.tag, 'release-')
+        run: |
+          cd docs
+          git push origin release
+
+      - name: Push docs.openra.net (Playtest)
+        if: startsWith(github.event.inputs.tag, 'playtest-')
+        run: |
+          cd docs
+          git push origin playtest
--- a/.github/workflows/packaging.yml
+++ b/.github/workflows/packaging.yml
@@ -16,7 +16,7 @@ jobs:
    runs-on: ubuntu-22.04
    steps:
      - name: Clone Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3

      - name: Prepare Environment
        run: echo "GIT_TAG=${GITHUB_REF#refs/tags/}" >> ${GITHUB_ENV}
@@ -40,10 +40,10 @@ jobs:
    runs-on: ubuntu-22.04
    steps:
      - name: Clone Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3

      - name: Install .NET 6.0
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v3
        with:
          dotnet-version: '6.0.x'

@@ -70,10 +70,10 @@ jobs:
    runs-on: macos-11
    steps:
      - name: Clone Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3

      - name: Install .NET 6.0
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v3
        with:
          dotnet-version: '6.0.x'

@@ -105,10 +105,10 @@ jobs:
    runs-on: ubuntu-22.04
    steps:
      - name: Clone Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3

      - name: Install .NET 6.0
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v3
        with:
          dotnet-version: '6.0.x'

--- a/3
+++ b/3
@@ -74,7 +74,6 @@ Also thanks to:
    * Glenn Martin Jensen (Baxxster)
    * Gordon Martin (Happy0)
    * Guido Lipke (LipkeGu)
-    * Guillermo Cuenca (Wylli)
    * Hervé Matysiak (Herve-M)
    * Huw Pascoe
    * Ian T. Jacobsen (Smilex)
@@ -120,7 +119,6 @@ Also thanks to:
    * Mike Gagné (AngryBirdz)
    * Muh
    * Mustafa Alperen Seki (MustaphaTR)
-    * Nathan Nichols (cracksmoka420)
    * Neil Shivkar (havok13888)
    * Nikolay Fomin (netnazgul)
    * Nooze
@@ -150,7 +148,6 @@ Also thanks to:
    * Teemu Nieminen (Temeez)
    * Thomas Christlieb (ThomasChr)
    * Tim Mylemans (gecko)
-    * Tinix
    * Tirili
    * Tomas Einarsson (Mesacer)
    * Tom van Leth (tovl)
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -5,16 +5,15 @@
    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
    <Optimize>true</Optimize>
-    <LangVersion>9</LangVersion>
+    <LangVersion>7.3</LangVersion>
    <DebugSymbols>true</DebugSymbols>
    <EngineRootPath Condition="'$(EngineRootPath)' == ''">..</EngineRootPath>
    <OutputPath>$(EngineRootPath)/bin</OutputPath>
    <PlatformTarget>AnyCPU</PlatformTarget>
    <ExternalConsole>false</ExternalConsole>
    <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
+    <CodeAnalysisRuleSet>$(EngineRootPath)/OpenRA.ruleset</CodeAnalysisRuleSet>
    <Nullable>disable</Nullable>
-    <Product>OpenRA</Product>
-    <Copyright>Copyright (c) The OpenRA Developers and Contributors</Copyright>
  </PropertyGroup>

  <PropertyGroup>
@@ -31,12 +30,6 @@
  <PropertyGroup Condition="'$(Configuration)' == 'Debug'">
    <DefineConstants>DEBUG;TRACE</DefineConstants>
    <Optimize>false</Optimize>
-    <!-- Enable only for Debug builds to improve compile-time performance for Release builds -->
-    <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
-    <!-- Enabling GenerateDocumentationFile is required for IDE0005 (Remove unnecessary import)
-      rule to run in command line builds. https://github.com/dotnet/roslyn/issues/41640
-      Enable only for Debug builds to improve compile-time performance for Release builds -->
-    <GenerateDocumentationFile>true</GenerateDocumentationFile>
  </PropertyGroup>

  <ItemGroup>
@@ -51,10 +44,9 @@
    </ItemGroup>
  </Target>

-  <!-- StyleCop/Roslynator -->
+  <!-- StyleCop -->
  <ItemGroup>
-    <PackageReference Include="StyleCop.Analyzers" Version="1.2.0-beta.435" PrivateAssets="All" />
-    <!-- Roslynator analyzers fail to run under Mono (AD0001) -->
-    <PackageReference Include="Roslynator.Analyzers" Version="4.2.0" PrivateAssets="All" Condition="'$(MSBuildRuntimeType)'!='Mono'" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.2" PrivateAssets="All" />
+    <PackageReference Include="StyleCop.Analyzers" Version="1.1.118" PrivateAssets="All" />
  </ItemGroup>
 </Project>
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -17,7 +17,7 @@ Run the game with `launch-game.cmd`. It can be handed arguments that specify the
 Linux
 =====

-.NET 6 or Mono (version 6.12 or later) is required to compile OpenRA. We recommend using .NET 6 when possible, as Mono is poorly packaged by most Linux distributions (e.g. missing the required `msbuild` toolchain), and has been deprecated as a standalone project.
+.NET 6 or Mono (version 6.4 or later) is required to compile OpenRA. We recommend using .NET 6 when possible, as Mono is poorly packaged by most Linux distributions (e.g. missing the required `msbuild` toolchain), and has been deprecated as a standalone project.

 The [.NET 6 download page](https://dotnet.microsoft.com/download/dotnet/6.0) provides repositories for various package managers and binary releases for several architectures. If you prefer to use Mono, we suggest adding the [upstream repository](https://www.mono-project.com/download/stable/#download-lin) for your distro to obtain the latest version and the `msbuild` toolchain.

@@ -78,6 +78,6 @@ Type `sudo make install` for system-wide installation. Run `sudo make install-li
 macOS
 =====

-[.NET 6](https://dotnet.microsoft.com/download/dotnet/6.0) or [Mono](https://www.mono-project.com/download/stable/#download-mac) (version 6.12 or later) is required to compile OpenRA. We recommend using .NET 6 unless you are running a very old version of macOS (10.9 through 10.14).
+[.NET 6](https://dotnet.microsoft.com/download/dotnet/6.0) or [Mono](https://www.mono-project.com/download/stable/#download-mac) (version 6.4 or later) is required to compile OpenRA. We recommend using .NET 6 unless you are running a very old version of macOS (10.9 through 10.14).

 To compile OpenRA, run `make` from the command line (or `make RUNTIME=mono` if using Mono). Run with `./launch-game.sh`.
--- a/25
+++ b/25
@@ -3,7 +3,7 @@
 # to compile, run:
 #   make
 #
-# to compile using Mono (version 6.12 or greater) instead of .NET 6, run:
+# to compile using Mono (version 6.4 or greater) instead of .NET 6, run:
 #   make RUNTIME=mono
 #
 # to compile using system libraries for native dependencies, run:
@@ -59,7 +59,6 @@ RM_RF = $(RM) -rf
 RUNTIME ?= net6
 CONFIGURATION ?= Release
 DOTNET_RID = $(shell ${DOTNET} --info | grep RID: | cut -w -f3)
-ARCH_X64 = $(shell echo ${DOTNET_RID} | grep x64)

 # Only for use in target version:
 VERSION := $(shell git name-rev --name-only --tags --no-undefined HEAD 2>/dev/null || (c=$$(git rev-parse --short HEAD 2>/dev/null) && echo git-$$c))
@@ -69,7 +68,7 @@ ifndef TARGETPLATFORM
 UNAME_S := $(shell uname -s)
 UNAME_M := $(shell uname -m)
 ifeq ($(UNAME_S),Darwin)
-ifeq ($(ARCH_X64),)
+ifeq ($(RUNTIME)-$(DOTNET_RID),net6-osx-arm64)
 TARGETPLATFORM = osx-arm64
 else
 TARGETPLATFORM = osx-x64
@@ -92,7 +91,7 @@ endif
 all:
 	@echo "Compiling in ${CONFIGURATION} mode..."
 ifeq ($(RUNTIME), mono)
-	@command -v $(firstword $(MSBUILD)) >/dev/null || (echo "OpenRA requires the '$(MSBUILD)' tool provided by Mono >= 6.12."; exit 1)
+	@command -v $(firstword $(MSBUILD)) >/dev/null || (echo "OpenRA requires the '$(MSBUILD)' tool provided by Mono >= 6.4."; exit 1)
 	@$(MSBUILD) -t:Build -restore -p:Configuration=${CONFIGURATION} -p:TargetPlatform=$(TARGETPLATFORM)
 else
 	@$(DOTNET) build -c ${CONFIGURATION} -nologo -p:TargetPlatform=$(TARGETPLATFORM)
@@ -112,10 +111,11 @@ check:
 	@echo
 	@echo "Compiling in Debug mode..."
 ifeq ($(RUNTIME), mono)
-	@$(MSBUILD) -t:clean\;build -restore -p:Configuration=Debug -warnaserror -p:TargetPlatform=$(TARGETPLATFORM)
+# Enabling EnforceCodeStyleInBuild and GenerateDocumentationFile as a workaround for some code style rules (in particular IDE0005) being bugged and not reporting warnings/errors otherwise.
+	@$(MSBUILD) -t:build -restore -p:Configuration=Debug -warnaserror -p:TargetPlatform=$(TARGETPLATFORM) -p:EnforceCodeStyleInBuild=true -p:GenerateDocumentationFile=true
 else
-	@$(DOTNET) clean -c Debug --nologo --verbosity minimal
-	@$(DOTNET) build -c Debug -nologo -warnaserror -p:TargetPlatform=$(TARGETPLATFORM)
+# Enabling EnforceCodeStyleInBuild and GenerateDocumentationFile as a workaround for some code style rules (in particular IDE0005) being bugged and not reporting warnings/errors otherwise.
+	@$(DOTNET) build -c Debug -nologo -warnaserror -p:TargetPlatform=$(TARGETPLATFORM) -p:EnforceCodeStyleInBuild=true -p:GenerateDocumentationFile=true
 endif
 ifeq ($(TARGETPLATFORM), unix-generic)
 	@./configure-system-libraries.sh
@@ -130,7 +130,7 @@ endif
 check-scripts:
 	@echo
 	@echo "Checking for Lua syntax errors..."
-	@find mods/*/maps/ mods/*/scripts/ -iname "*.lua" -print0 | xargs -0n1 luac -p
+	@find lua/ mods/*/{maps,scripts}/ -iname "*.lua" -print0 | xargs -0n1 luac -p

 test: all
 	@echo
@@ -146,11 +146,6 @@ test: all
 	@echo "Testing Red Alert mod MiniYAML..."
 	@./utility.sh ra --check-yaml

-tests:
-	@dotnet build OpenRA.Test/OpenRA.Test.csproj -c Debug --nologo -p:TargetPlatform=$(TARGETPLATFORM)
-	@echo
-	@dotnet test bin/OpenRA.Test.dll --test-adapter-path:.
-
 ############# LOCAL INSTALLATION AND DOWNSTREAM PACKAGING ##############
 #
 version: VERSION mods/ra/mod.yaml mods/cnc/mod.yaml mods/d2k/mod.yaml mods/ts/mod.yaml mods/modcontent/mod.yaml mods/all/mod.yaml
@@ -178,14 +173,14 @@ help:
 	@echo 'to compile, run:'
 	@echo '  make'
 	@echo
-	@echo 'to compile using Mono (version 6.12 or greater) instead of .NET 6, run:'
+	@echo 'to compile using Mono (version 6.4 or greater) instead of .NET 6, run:'
 	@echo '  make RUNTIME=mono'
 	@echo
 	@echo 'to compile using system libraries for native dependencies, run:'
 	@echo '  make [RUNTIME=net6] TARGETPLATFORM=unix-generic'
 	@echo
 	@echo 'to check the official mods for erroneous yaml files, run:'
-	@echo '  make [RUNTIME=net6] [TREAT_WARNINGS_AS_ERRORS=false] test'
+	@echo '  make [RUNTIME=net6] test'
 	@echo
 	@echo 'to check the engine and official mod dlls for code style violations, run:'
 	@echo '  make [RUNTIME=net6] check'
--- a/OpenRA.Game/Activities/Activity.cs
+++ b/OpenRA.Game/Activities/Activity.cs
@@ -86,7 +86,7 @@ namespace OpenRA.Activities
 		bool firstRunCompleted;
 		bool lastRun;

-		protected Activity()
+		public Activity()
 		{
 			IsInterruptible = true;
 			ChildHasPriority = true;
@@ -146,22 +146,18 @@ namespace OpenRA.Activities
 		}

 		/// <summary>
-		/// <para>
 		/// Called every tick to run activity logic. Returns false if the activity should
 		/// remain active, or true if it is complete. Cancelled activities must ensure they
 		/// return the actor to a consistent state before returning true.
-		/// </para>
-		/// <para>
+		///
 		/// Child activities can be queued using QueueChild, and these will be ticked
 		/// instead of the parent while they are active. Activities that need to run logic
 		/// in parallel with child activities should set ChildHasPriority to false and
 		/// manually call TickChildren.
-		/// </para>
-		/// <para>
+		///
 		/// Queuing one or more child activities and returning true is valid, and causes
 		/// the activity to be completed immediately (without ticking again) once the
 		/// children have completed.
-		/// </para>
 		/// </summary>
 		public virtual bool Tick(Actor self)
 		{
@@ -226,11 +222,10 @@ namespace OpenRA.Activities
 		}

 		/// <summary>
-		/// <para>Prints the activity tree, starting from the top or optionally from a given origin.</para>
-		/// <para>
+		/// Prints the activity tree, starting from the top or optionally from a given origin.
+		///
 		/// Call this method from any place that's called during a tick, such as the Tick() method itself or
 		/// the Before(First|Last)Run() methods. The origin activity will be marked in the output.
-		/// </para>
 		/// </summary>
 		/// <param name="self">The actor performing this activity.</param>
 		/// <param name="origin">Activity from which to start traversing, and which to mark. If null, mark the calling activity, and start traversal from the top.</param>
--- a/OpenRA.Game/Actor.cs
+++ b/OpenRA.Game/Actor.cs
@@ -35,9 +35,6 @@ namespace OpenRA

 	public sealed class Actor : IScriptBindable, IScriptNotifyBind, ILuaTableBinding, ILuaEqualityBinding, ILuaToStringBinding, IEquatable<Actor>, IDisposable
 	{
-		/// <summary>Value used to represent an invalid token.</summary>
-		public const int InvalidConditionToken = -1;
-
 		internal readonly struct SyncHash
 		{
 			public readonly ISync Trait;
@@ -71,12 +68,7 @@ namespace OpenRA
 		public IEffectiveOwner EffectiveOwner { get; }
 		public IOccupySpace OccupiesSpace { get; }
 		public ITargetable[] Targetables { get; }
-		public IEnumerable<ITargetablePositions> EnabledTargetablePositions { get; }
-		readonly ICrushable[] crushables;
-		public ICrushable[] Crushables
-		{
-			get => crushables ?? throw new InvalidOperationException($"Crushables for {Info.Name} are not initialized.");
-		}
+		public IEnumerable<ITargetablePositions> EnabledTargetablePositions { get; private set; }

 		public bool IsIdle => CurrentActivity == null;
 		public bool IsDead => Disposed || (health != null && health.IsDead);
@@ -86,24 +78,27 @@ namespace OpenRA

 		public WRot Orientation => facing?.Orientation ?? WRot.None;

-		sealed class ConditionState
+		/// <summary>Value used to represent an invalid token.</summary>
+		public static readonly int InvalidConditionToken = -1;
+
+		class ConditionState
 		{
 			/// <summary>Delegates that have registered to be notified when this condition changes.</summary>
-			public readonly List<VariableObserverNotifier> Notifiers = new();
+			public readonly List<VariableObserverNotifier> Notifiers = new List<VariableObserverNotifier>();

 			/// <summary>Unique integers identifying granted instances of the condition.</summary>
-			public readonly HashSet<int> Tokens = new();
+			public readonly HashSet<int> Tokens = new HashSet<int>();
 		}

-		readonly Dictionary<string, ConditionState> conditionStates = new();
+		readonly Dictionary<string, ConditionState> conditionStates = new Dictionary<string, ConditionState>();

 		/// <summary>Each granted condition receives a unique token that is used when revoking.</summary>
-		readonly Dictionary<int, string> conditionTokens = new();
+		readonly Dictionary<int, string> conditionTokens = new Dictionary<int, string>();

 		int nextConditionToken = 1;

 		/// <summary>Cache of condition -> enabled state for quick evaluation of token counter conditions.</summary>
-		readonly Dictionary<string, int> conditionCache = new();
+		readonly Dictionary<string, int> conditionCache = new Dictionary<string, int>();

 		/// <summary>Read-only version of conditionCache that is passed to IConditionConsumers.</summary>
 		readonly IReadOnlyDictionary<string, int> readOnlyConditionCache;
@@ -160,7 +155,6 @@ namespace OpenRA
 				var targetablesList = new List<ITargetable>();
 				var targetablePositionsList = new List<ITargetablePositions>();
 				var syncHashesList = new List<SyncHash>();
-				var crushablesList = new List<ICrushable>();

 				foreach (var traitInfo in Info.TraitsInConstructOrder())
 				{
@@ -187,7 +181,6 @@ namespace OpenRA
 					{ if (trait is ITargetable t) targetablesList.Add(t); }
 					{ if (trait is ITargetablePositions t) targetablePositionsList.Add(t); }
 					{ if (trait is ISync t) syncHashesList.Add(new SyncHash(t)); }
-					{ if (trait is ICrushable t) crushablesList.Add(t); }
 				}

 				resolveOrders = resolveOrdersList.ToArray();
@@ -202,7 +195,6 @@ namespace OpenRA
 				EnabledTargetablePositions = targetablePositions.Where(Exts.IsTraitEnabled);
 				enabledTargetableWorldPositions = EnabledTargetablePositions.SelectMany(tp => tp.TargetablePositions(this));
 				SyncHashes = syncHashesList.ToArray();
-				crushables = crushablesList.ToArray();
 			}
 		}

@@ -595,7 +587,7 @@ namespace OpenRA
 			return InvalidConditionToken;
 		}

-		/// <summary>Returns whether the specified token is valid for RevokeCondition.</summary>
+		/// <summary>Returns whether the specified token is valid for RevokeCondition</summary>
 		public bool TokenValid(int token)
 		{
 			return conditionTokens.ContainsKey(token);
@@ -608,7 +600,8 @@ namespace OpenRA
 		Lazy<ScriptActorInterface> luaInterface;
 		public void OnScriptBind(ScriptContext context)
 		{
-			luaInterface ??= Exts.Lazy(() => new ScriptActorInterface(context, this));
+			if (luaInterface == null)
+				luaInterface = Exts.Lazy(() => new ScriptActorInterface(context, this));
 		}

 		public LuaValue this[LuaRuntime runtime, LuaValue keyValue]
--- a/OpenRA.Game/CPos.cs
+++ b/OpenRA.Game/CPos.cs
@@ -41,7 +41,7 @@ namespace OpenRA
 			Bits = (x & 0xFFF) << 20 | (y & 0xFFF) << 8 | layer;
 		}

-		public static readonly CPos Zero = new(0, 0, 0);
+		public static readonly CPos Zero = new CPos(0, 0, 0);

 		public static explicit operator CPos(int2 a) { return new CPos(a.X, a.Y); }

@@ -56,7 +56,7 @@ namespace OpenRA
 		public override int GetHashCode() { return Bits.GetHashCode(); }

 		public bool Equals(CPos other) { return Bits == other.Bits; }
-		public override bool Equals(object obj) { return obj is CPos cell && Equals(cell); }
+		public override bool Equals(object obj) { return obj is CPos && Equals((CPos)obj); }

 		public override string ToString()
 		{
--- a/OpenRA.Game/CVec.cs
+++ b/OpenRA.Game/CVec.cs
@@ -22,7 +22,7 @@ namespace OpenRA
 		public readonly int X, Y;

 		public CVec(int x, int y) { X = x; Y = y; }
-		public static readonly CVec Zero = new(0, 0);
+		public static readonly CVec Zero = new CVec(0, 0);

 		public static CVec operator +(CVec a, CVec b) { return new CVec(a.X + b.X, a.Y + b.Y); }
 		public static CVec operator -(CVec a, CVec b) { return new CVec(a.X - b.X, a.Y - b.Y); }
@@ -55,20 +55,20 @@ namespace OpenRA
 		public override int GetHashCode() { return X.GetHashCode() ^ Y.GetHashCode(); }

 		public bool Equals(CVec other) { return other == this; }
-		public override bool Equals(object obj) { return obj is CVec vec && Equals(vec); }
+		public override bool Equals(object obj) { return obj is CVec && Equals((CVec)obj); }

 		public override string ToString() { return X + "," + Y; }

 		public static readonly CVec[] Directions =
 		{
-			new(-1, -1),
-			new(-1,  0),
-			new(-1,  1),
-			new(0, -1),
-			new(0,  1),
-			new(1, -1),
-			new(1,  0),
-			new(1,  1),
+			new CVec(-1, -1),
+			new CVec(-1,  0),
+			new CVec(-1,  1),
+			new CVec(0, -1),
+			new CVec(0,  1),
+			new CVec(1, -1),
+			new CVec(1,  0),
+			new CVec(1,  1),
 		};

 		#region Scripting interface
--- a/OpenRA.Game/CryptoUtil.cs
+++ b/OpenRA.Game/CryptoUtil.cs
@@ -22,9 +22,6 @@ namespace OpenRA
 		// Fixed byte pattern for the OID header
 		static readonly byte[] OIDHeader = { 0x30, 0xD, 0x6, 0x9, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0xD, 0x1, 0x1, 0x1, 0x5, 0x0 };

-		static readonly char[] HexUpperAlphabet = "0123456789ABCDEF".ToArray();
-		static readonly char[] HexLowerAlphabet = "0123456789abcdef".ToArray();
-
 		public static string PublicKeyFingerprint(RSAParameters parameters)
 		{
 			// Public key fingerprint is defined as the SHA1 of the modulus + exponent bytes
@@ -56,33 +53,33 @@ namespace OpenRA
 				using (var s = new MemoryStream(data))
 				{
 					// SEQUENCE
-					s.ReadUInt8();
+					s.ReadByte();
 					ReadTLVLength(s);

 					// SEQUENCE -> fixed header junk
-					s.ReadUInt8();
+					s.ReadByte();
 					var headerLength = ReadTLVLength(s);
 					s.Position += headerLength;

 					// SEQUENCE -> BIT_STRING
-					s.ReadUInt8();
+					s.ReadByte();
 					ReadTLVLength(s);
-					s.ReadUInt8();
+					s.ReadByte();

 					// SEQUENCE -> BIT_STRING -> SEQUENCE
-					s.ReadUInt8();
+					s.ReadByte();
 					ReadTLVLength(s);

 					// SEQUENCE -> BIT_STRING -> SEQUENCE -> INTEGER (modulus)
-					s.ReadUInt8();
+					s.ReadByte();
 					var modulusLength = ReadTLVLength(s);
-					s.ReadUInt8();
+					s.ReadByte();
 					var modulus = s.ReadBytes(modulusLength - 1);

 					// SEQUENCE -> BIT_STRING -> SEQUENCE -> INTEGER (exponent)
-					s.ReadUInt8();
+					s.ReadByte();
 					var exponentLength = ReadTLVLength(s);
-					s.ReadUInt8();
+					s.ReadByte();
 					var exponent = s.ReadBytes(exponentLength - 1);

 					return new RSAParameters
@@ -161,13 +158,13 @@ namespace OpenRA

 		static int ReadTLVLength(Stream s)
 		{
-			var length = s.ReadUInt8();
+			var length = s.ReadByte();
 			if (length < 0x80)
 				return length;

-			Span<byte> data = stackalloc byte[4];
-			s.ReadBytes(data[..Math.Min(length & 0x7F, 4)]);
-			return BitConverter.ToInt32(data);
+			var data = new byte[4];
+			s.ReadBytes(data, 0, Math.Min(length & 0x7F, 4));
+			return BitConverter.ToInt32(data.ToArray(), 0);
 		}

 		static int TripletFullLength(int dataLength)
@@ -190,10 +187,8 @@ namespace OpenRA
 			}
 			catch (Exception e)
 			{
-				Log.Write("debug", "Failed to decrypt string with exception:");
-				Log.Write("debug", e);
-				Console.WriteLine("String decryption failed:");
-				Console.WriteLine(e);
+				Log.Write("debug", "Failed to decrypt string with exception: {0}", e);
+				Console.WriteLine("String decryption failed: {0}", e);
 				return null;
 			}
 		}
@@ -216,10 +211,8 @@ namespace OpenRA
 			}
 			catch (Exception e)
 			{
-				Log.Write("debug", "Failed to sign string with exception");
-				Log.Write("debug", e);
-				Console.WriteLine("String signing failed:");
-				Console.WriteLine(e);
+				Log.Write("debug", "Failed to sign string with exception: {0}", e);
+				Console.WriteLine("String signing failed: {0}", e);
 				return null;
 			}
 		}
@@ -242,54 +235,27 @@ namespace OpenRA
 			}
 			catch (Exception e)
 			{
-				Log.Write("debug", "Failed to verify signature with exception:");
-				Log.Write("debug", e);
-				Console.WriteLine("Signature validation failed:");
-				Console.WriteLine(e);
+				Log.Write("debug", "Failed to verify signature with exception: {0}", e);
+				Console.WriteLine("Signature validation failed: {0}", e);
 				return false;
 			}
 		}

 		public static string SHA1Hash(Stream data)
 		{
-			using var csp = SHA1.Create();
-			return ToHex(csp.ComputeHash(data), true);
+			using (var csp = SHA1.Create())
+				return new string(csp.ComputeHash(data).SelectMany(a => a.ToString("x2")).ToArray());
 		}

 		public static string SHA1Hash(byte[] data)
 		{
-			using var csp = SHA1.Create();
-			return ToHex(csp.ComputeHash(data), true);
+			using (var csp = SHA1.Create())
+				return new string(csp.ComputeHash(data).SelectMany(a => a.ToString("x2")).ToArray());
 		}

 		public static string SHA1Hash(string data)
 		{
 			return SHA1Hash(Encoding.UTF8.GetBytes(data));
 		}
-
-		public static string ToHex(ReadOnlySpan<byte> source, bool lowerCase = false)
-		{
-			if (source.Length == 0)
-				return string.Empty;
-
-			// excessively avoid stack overflow if source is too large (considering that we're allocating a new string)
-			var buffer = source.Length <= 256 ? stackalloc char[source.Length * 2] : new char[source.Length * 2];
-			return ToHexInternal(source, buffer, lowerCase);
-		}
-
-		static string ToHexInternal(ReadOnlySpan<byte> source, Span<char> buffer, bool lowerCase)
-		{
-			var sourceIndex = 0;
-			var alphabet = lowerCase ? HexLowerAlphabet : HexUpperAlphabet;
-
-			for (var i = 0; i < buffer.Length; i += 2)
-			{
-				var b = source[sourceIndex++];
-				buffer[i] = alphabet[b >> 4];
-				buffer[i + 1] = alphabet[b & 0xF];
-			}
-
-			return new string(buffer);
-		}
 	}
 }
--- a/OpenRA.Game/Effects/AsyncAction.cs
+++ b/OpenRA.Game/Effects/AsyncAction.cs
@@ -0,0 +1,39 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using OpenRA.Graphics;
+
+namespace OpenRA.Effects
+{
+	public class AsyncAction : IEffect
+	{
+		readonly Action a;
+		readonly IAsyncResult ar;
+
+		public AsyncAction(IAsyncResult ar, Action a)
+		{
+			this.a = a;
+			this.ar = ar;
+		}
+
+		public void Tick(World world)
+		{
+			if (ar.IsCompleted)
+			{
+				world.AddFrameEndTask(w => { w.Remove(this); a(); });
+			}
+		}
+
+		public IEnumerable<IRenderable> Render(WorldRenderer r) { yield break; }
+	}
+}
--- a/OpenRA.Game/ExternalMods.cs
+++ b/OpenRA.Game/ExternalMods.cs
@@ -41,7 +41,7 @@ namespace OpenRA

 	public class ExternalMods : IReadOnlyDictionary<string, ExternalMod>
 	{
-		readonly Dictionary<string, ExternalMod> mods = new();
+		readonly Dictionary<string, ExternalMod> mods = new Dictionary<string, ExternalMod>();
 		readonly SheetBuilder sheetBuilder;

 		Sheet CreateSheet()
@@ -66,7 +66,6 @@ namespace OpenRA
 			// Several types of support directory types are available, depending on
 			// how the player has installed and launched the game.
 			// Read registration metadata from all of them
-			var stringPool = new HashSet<string>(); // Reuse common strings in YAML
 			foreach (var source in GetSupportDirs(ModRegistration.User | ModRegistration.System))
 			{
 				var metadataPath = Path.Combine(source, "ModMetadata");
@@ -77,13 +76,13 @@ namespace OpenRA
 				{
 					try
 					{
-						var yaml = MiniYaml.FromFile(path, stringPool: stringPool).First().Value;
+						var yaml = MiniYaml.FromStream(File.OpenRead(path), path).First().Value;
 						LoadMod(yaml, path);
 					}
 					catch (Exception e)
 					{
-						Log.Write("debug", $"Failed to parse mod metadata file '{path}'");
-						Log.Write("debug", e);
+						Log.Write("debug", "Failed to parse mod metadata file '{0}'", path);
+						Log.Write("debug", e.ToString());
 					}
 				}
 			}
@@ -95,17 +94,17 @@ namespace OpenRA

 			if (sheetBuilder != null)
 			{
-				var iconNode = yaml.NodeWithKeyOrDefault("Icon");
+				var iconNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Icon");
 				if (iconNode != null && !string.IsNullOrEmpty(iconNode.Value.Value))
 					using (var stream = new MemoryStream(Convert.FromBase64String(iconNode.Value.Value)))
 						mod.Icon = sheetBuilder.Add(new Png(stream));

-				var icon2xNode = yaml.NodeWithKeyOrDefault("Icon2x");
+				var icon2xNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Icon2x");
 				if (icon2xNode != null && !string.IsNullOrEmpty(icon2xNode.Value.Value))
 					using (var stream = new MemoryStream(Convert.FromBase64String(icon2xNode.Value.Value)))
 						mod.Icon2x = sheetBuilder.Add(new Png(stream), 1f / 2);

-				var icon3xNode = yaml.NodeWithKeyOrDefault("Icon3x");
+				var icon3xNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Icon3x");
 				if (icon3xNode != null && !string.IsNullOrEmpty(icon3xNode.Value.Value))
 					using (var stream = new MemoryStream(Convert.FromBase64String(icon3xNode.Value.Value)))
 						mod.Icon3x = sheetBuilder.Add(new Png(stream), 1f / 3);
@@ -123,7 +122,7 @@ namespace OpenRA
 				return;

 			var key = ExternalMod.MakeKey(mod);
-			var yaml = new MiniYamlNode("Registration", new MiniYaml("", new[]
+			var yaml = new MiniYamlNode("Registration", new MiniYaml("", new List<MiniYamlNode>()
 			{
 				new MiniYamlNode("Id", mod.Id),
 				new MiniYamlNode("Version", mod.Metadata.Version),
@@ -132,21 +131,17 @@ namespace OpenRA
 				new MiniYamlNode("LaunchArgs", new[] { "Game.Mod=" + mod.Id }.Concat(launchArgs).JoinWith(", "))
 			}));

-			var iconNodes = new List<MiniYamlNode>();
-
 			using (var stream = mod.Package.GetStream("icon.png"))
 				if (stream != null)
-					iconNodes.Add(new MiniYamlNode("Icon", Convert.ToBase64String(stream.ReadAllBytes())));
+					yaml.Value.Nodes.Add(new MiniYamlNode("Icon", Convert.ToBase64String(stream.ReadAllBytes())));

 			using (var stream = mod.Package.GetStream("icon-2x.png"))
 				if (stream != null)
-					iconNodes.Add(new MiniYamlNode("Icon2x", Convert.ToBase64String(stream.ReadAllBytes())));
+					yaml.Value.Nodes.Add(new MiniYamlNode("Icon2x", Convert.ToBase64String(stream.ReadAllBytes())));

 			using (var stream = mod.Package.GetStream("icon-3x.png"))
 				if (stream != null)
-					iconNodes.Add(new MiniYamlNode("Icon3x", Convert.ToBase64String(stream.ReadAllBytes())));
-
-			yaml = yaml.WithValue(yaml.Value.WithNodesAppended(iconNodes));
+					yaml.Value.Nodes.Add(new MiniYamlNode("Icon3x", Convert.ToBase64String(stream.ReadAllBytes())));

 			var sources = new HashSet<string>();
 			if (registration.HasFlag(ModRegistration.System))
@@ -179,19 +174,17 @@ namespace OpenRA
 				catch (Exception e)
 				{
 					Log.Write("debug", "Failed to register current mod metadata");
-					Log.Write("debug", e);
+					Log.Write("debug", e.ToString());
 				}
 			}
 		}

 		/// <summary>
 		/// Removes invalid mod registrations:
-		/// <list type="bullet">
-		/// <item>LaunchPath no longer exists.</item>
-		/// <item>LaunchPath and mod id matches the active mod, but the version is different.</item>
-		/// <item>Filename doesn't match internal key.</item>
-		/// <item>Fails to parse as a mod registration.</item>
-		/// </list>
+		/// * LaunchPath no longer exists
+		/// * LaunchPath and mod id matches the active mod, but the version is different
+		/// * Filename doesn't match internal key
+		/// * Fails to parse as a mod registration
 		/// </summary>
 		internal void ClearInvalidRegistrations(ModRegistration registration)
 		{
@@ -206,7 +199,7 @@ namespace OpenRA
 					string modKey = null;
 					try
 					{
-						var yaml = MiniYaml.FromFile(path).First().Value;
+						var yaml = MiniYaml.FromStream(File.OpenRead(path), path).First().Value;
 						var m = FieldLoader.Load<ExternalMod>(yaml);
 						modKey = ExternalMod.MakeKey(m);

@@ -218,8 +211,8 @@ namespace OpenRA
 					}
 					catch (Exception e)
 					{
-						Log.Write("debug", $"Failed to parse mod metadata file '{path}'");
-						Log.Write("debug", e);
+						Log.Write("debug", "Failed to parse mod metadata file '{0}'", path);
+						Log.Write("debug", e.ToString());
 					}

 					// Remove from the ingame mod switcher
@@ -230,12 +223,12 @@ namespace OpenRA
 					try
 					{
 						File.Delete(path);
-						Log.Write("debug", $"Removed invalid mod metadata file '{path}'");
+						Log.Write("debug", "Removed invalid mod metadata file '{0}'", path);
 					}
 					catch (Exception e)
 					{
-						Log.Write("debug", $"Failed to remove mod metadata file '{path}'");
-						Log.Write("debug", e);
+						Log.Write("debug", "Failed to remove mod metadata file '{0}'", path);
+						Log.Write("debug", e.ToString());
 					}
 				}
 			}
@@ -256,13 +249,13 @@ namespace OpenRA
 				}
 				catch (Exception e)
 				{
-					Log.Write("debug", $"Failed to remove mod metadata file '{path}'");
-					Log.Write("debug", e);
+					Log.Write("debug", "Failed to remove mod metadata file '{0}'", path);
+					Log.Write("debug", e.ToString());
 				}
 			}
 		}

-		static IEnumerable<string> GetSupportDirs(ModRegistration registration)
+		IEnumerable<string> GetSupportDirs(ModRegistration registration)
 		{
 			var sources = new HashSet<string>(4);
 			if (registration.HasFlag(ModRegistration.System))
--- a/OpenRA.Game/Exts.cs
+++ b/OpenRA.Game/Exts.cs
@@ -22,14 +22,20 @@ namespace OpenRA
 {
 	public static class Exts
 	{
-		public static string FormatInvariant(this string format, params object[] args)
+		public static bool IsUppercase(this string str)
 		{
-			return string.Format(CultureInfo.InvariantCulture, format, args);
+			return string.Compare(str.ToUpperInvariant(), str, false) == 0;
 		}

-		public static string FormatCurrent(this string format, params object[] args)
+		public static string F(this string fmt, params object[] args)
 		{
-			return string.Format(CultureInfo.CurrentCulture, format, args);
+			return string.Format(fmt, args);
+		}
+
+		public static T WithDefault<T>(T def, Func<T> f)
+		{
+			try { return f(); }
+			catch { return def; }
 		}

 		public static Lazy<T> Lazy<T>(Func<T> p) { return new Lazy<T>(p); }
@@ -39,16 +45,21 @@ namespace OpenRA
 			return a.GetTypes().Select(t => t.Namespace).Distinct().Where(n => n != null);
 		}

-		public static bool HasAttribute<TAttribute>(this MemberInfo mi)
-			where TAttribute : Attribute
+		public static bool HasAttribute<T>(this MemberInfo mi)
 		{
-			return Attribute.IsDefined(mi, typeof(TAttribute));
+			return Attribute.IsDefined(mi, typeof(T));
 		}

-		public static TAttribute[] GetCustomAttributes<TAttribute>(this MemberInfo mi, bool inherit)
-			where TAttribute : Attribute
+		public static T[] GetCustomAttributes<T>(this MemberInfo mi, bool inherit)
+			where T : class
 		{
-			return (TAttribute[])mi.GetCustomAttributes(typeof(TAttribute), inherit);
+			return (T[])mi.GetCustomAttributes(typeof(T), inherit);
+		}
+
+		public static T[] GetCustomAttributes<T>(this ParameterInfo mi)
+			where T : class
+		{
+			return (T[])mi.GetCustomAttributes(typeof(T), true);
 		}

 		public static T Clamp<T>(this T val, T min, T max) where T : IComparable<T>
@@ -108,57 +119,23 @@ namespace OpenRA

 		public static V GetOrAdd<K, V>(this Dictionary<K, V> d, K k, V v)
 		{
-#if NET5_0_OR_GREATER
-			// SAFETY: Dictionary cannot be modified whilst the ref is alive.
-			ref var value = ref System.Runtime.InteropServices.CollectionsMarshal.GetValueRefOrAddDefault(d, k, out var exists);
-			if (!exists)
-				value = v;
-			return value;
-#else
 			if (!d.TryGetValue(k, out var ret))
 				d.Add(k, ret = v);
 			return ret;
-#endif
 		}

 		public static V GetOrAdd<K, V>(this Dictionary<K, V> d, K k, Func<K, V> createFn)
 		{
-			// Cannot use CollectionsMarshal.GetValueRefOrAddDefault here,
-			// the creation function could mutate the dictionary which would invalidate the ref.
 			if (!d.TryGetValue(k, out var ret))
 				d.Add(k, ret = createFn(k));
 			return ret;
 		}

-		public static T GetOrAdd<T>(this HashSet<T> set, T value)
-		{
-			if (!set.TryGetValue(value, out var ret))
-				set.Add(ret = value);
-			return ret;
-		}
-
-		public static T GetOrAdd<T>(this HashSet<T> set, T value, Func<T, T> createFn)
-		{
-			if (!set.TryGetValue(value, out var ret))
-				set.Add(ret = createFn(value));
-			return ret;
-		}
-
 		public static int IndexOf<T>(this T[] array, T value)
 		{
 			return Array.IndexOf(array, value);
 		}

-		public static T FirstOrDefault<T>(this T[] array, Predicate<T> match)
-		{
-			return Array.Find(array, match);
-		}
-
-		public static T FirstOrDefault<T>(this List<T> list, Predicate<T> match)
-		{
-			return list.Find(match);
-		}
-
 		public static T Random<T>(this IEnumerable<T> ts, MersenneTwister r)
 		{
 			return Random(ts, r, true);
@@ -171,8 +148,8 @@ namespace OpenRA

 		static T Random<T>(IEnumerable<T> ts, MersenneTwister r, bool throws)
 		{
-			var xs = ts as IReadOnlyCollection<T>;
-			xs ??= ts.ToList();
+			var xs = ts as ICollection<T>;
+			xs = xs ?? ts.ToList();
 			if (xs.Count == 0)
 			{
 				if (throws)
@@ -326,9 +303,9 @@ namespace OpenRA

 			// Adjust for other rounding modes
 			if (round == ISqrtRoundMode.Nearest && remainder > root)
-				root++;
+				root += 1;
 			else if (round == ISqrtRoundMode.Ceiling && root * root < number)
-				root++;
+				root += 1;

 			return root;
 		}
@@ -367,9 +344,9 @@ namespace OpenRA

 			// Adjust for other rounding modes
 			if (round == ISqrtRoundMode.Nearest && remainder > root)
-				root++;
+				root += 1;
 			else if (round == ISqrtRoundMode.Ceiling && root * root < number)
-				root++;
+				root += 1;

 			return root;
 		}
@@ -379,11 +356,6 @@ namespace OpenRA
 			return number * 46341 / 32768;
 		}

-		public static int MultiplyBySqrtTwoOverTwo(int number)
-		{
-			return (int)(number * 23170L / 32768L);
-		}
-
 		public static int IntegerDivisionRoundingAwayFromZero(int dividend, int divisor)
 		{
 			var quotient = Math.DivRem(dividend, divisor, out var remainder);
@@ -424,8 +396,8 @@ namespace OpenRA
 			string debugName, Func<TKey, string> logKey = null, Func<TElement, string> logValue = null)
 		{
 			// Fall back on ToString() if null functions are provided:
-			logKey ??= s => s.ToString();
-			logValue ??= s => s.ToString();
+			logKey = logKey ?? (s => s.ToString());
+			logValue = logValue ?? (s => s.ToString());

 			// Try to build a dictionary and log all duplicates found (if any):
 			var dupKeys = new Dictionary<TKey, List<string>>();
@@ -521,22 +493,17 @@ namespace OpenRA
 			return result;
 		}

-		public static byte ParseByteInvariant(string s)
-		{
-			return byte.Parse(s, NumberStyles.Integer, NumberFormatInfo.InvariantInfo);
-		}
-
-		public static short ParseInt16Invariant(string s)
-		{
-			return short.Parse(s, NumberStyles.Integer, NumberFormatInfo.InvariantInfo);
-		}
-
-		public static int ParseInt32Invariant(string s)
+		public static int ParseIntegerInvariant(string s)
 		{
 			return int.Parse(s, NumberStyles.Integer, NumberFormatInfo.InvariantInfo);
 		}

-		public static bool TryParseInt32Invariant(string s, out int i)
+		public static byte ParseByte(string s)
+		{
+			return byte.Parse(s, NumberStyles.Integer, NumberFormatInfo.InvariantInfo);
+		}
+
+		public static bool TryParseIntegerInvariant(string s, out int i)
 		{
 			return int.TryParse(s, NumberStyles.Integer, NumberFormatInfo.InvariantInfo, out i);
 		}
@@ -546,29 +513,9 @@ namespace OpenRA
 			return long.TryParse(s, NumberStyles.Integer, NumberFormatInfo.InvariantInfo, out i);
 		}

-		public static string ToStringInvariant(this byte i)
-		{
-			return i.ToString(NumberFormatInfo.InvariantInfo);
-		}
-
-		public static string ToStringInvariant(this byte i, string format)
-		{
-			return i.ToString(format, NumberFormatInfo.InvariantInfo);
-		}
-
-		public static string ToStringInvariant(this int i)
-		{
-			return i.ToString(NumberFormatInfo.InvariantInfo);
-		}
-
-		public static string ToStringInvariant(this int i, string format)
-		{
-			return i.ToString(format, NumberFormatInfo.InvariantInfo);
-		}
-
 		public static bool IsTraitEnabled<T>(this T trait)
 		{
-			return trait is not IDisabledTrait disabledTrait || !disabledTrait.IsTraitDisabled;
+			return !(trait is IDisabledTrait disabledTrait) || !disabledTrait.IsTraitDisabled;
 		}

 		public static T FirstEnabledTraitOrDefault<T>(this IEnumerable<T> ts)
@@ -629,7 +576,7 @@ namespace OpenRA
 			Current = default;
 		}

-		public readonly LineSplitEnumerator GetEnumerator() => this;
+		public LineSplitEnumerator GetEnumerator() => this;

 		public bool MoveNext()
 		{
@@ -648,8 +595,8 @@ namespace OpenRA
 				return true;
 			}

-			Current = span[..index];
-			str = span[(index + 1)..];
+			Current = span.Slice(0, index);
+			str = span.Slice(index + 1);
 			return true;
 		}

--- a/OpenRA.Game/FieldLoader.cs
+++ b/OpenRA.Game/FieldLoader.cs
@@ -56,20 +56,24 @@ namespace OpenRA
 		}

 		public static Func<string, Type, string, object> InvalidValueAction = (s, t, f) =>
+		{
 			throw new YamlException($"FieldLoader: Cannot parse `{s}` into `{f}.{t}` ");
+		};

 		public static Action<string, Type> UnknownFieldAction = (s, f) =>
+		{
 			throw new NotImplementedException($"FieldLoader: Missing field `{s}` on `{f.Name}`");
+		};

 		static readonly ConcurrentCache<Type, FieldLoadInfo[]> TypeLoadInfo =
-			new(BuildTypeLoadInfo);
+			new ConcurrentCache<Type, FieldLoadInfo[]>(BuildTypeLoadInfo);
 		static readonly ConcurrentCache<string, BooleanExpression> BooleanExpressionCache =
-			new(expression => new BooleanExpression(expression));
+			new ConcurrentCache<string, BooleanExpression>(expression => new BooleanExpression(expression));
 		static readonly ConcurrentCache<string, IntegerExpression> IntegerExpressionCache =
-			new(expression => new IntegerExpression(expression));
+			new ConcurrentCache<string, IntegerExpression>(expression => new IntegerExpression(expression));

 		static readonly Dictionary<Type, Func<string, Type, string, MemberInfo, object>> TypeParsers =
-			new()
+			new Dictionary<Type, Func<string, Type, string, MemberInfo, object>>()
 			{
 				{ typeof(int), ParseInt },
 				{ typeof(ushort), ParseUShort },
@@ -87,7 +91,6 @@ namespace OpenRA
 				{ typeof(WAngle), ParseWAngle },
 				{ typeof(WRot), ParseWRot },
 				{ typeof(CPos), ParseCPos },
-				{ typeof(CPos[]), ParseCPosArray },
 				{ typeof(CVec), ParseCVec },
 				{ typeof(CVec[]), ParseCVecArray },
 				{ typeof(BooleanExpression), ParseBooleanExpression },
@@ -104,7 +107,7 @@ namespace OpenRA
 			};

 		static readonly Dictionary<Type, Func<string, Type, string, MiniYaml, MemberInfo, object>> GenericTypeParsers =
-			new()
+			new Dictionary<Type, Func<string, Type, string, MiniYaml, MemberInfo, object>>()
 			{
 				{ typeof(HashSet<>), ParseHashSetOrList },
 				{ typeof(List<>), ParseHashSetOrList },
@@ -113,19 +116,10 @@ namespace OpenRA
 				{ typeof(Nullable<>), ParseNullable },
 			};

-		static readonly object BoxedTrue = true;
-		static readonly object BoxedFalse = false;
-		static readonly object[] BoxedInts = Exts.MakeArray(33, i => (object)i);
-
 		static object ParseInt(string fieldName, Type fieldType, string value, MemberInfo field)
 		{
-			if (Exts.TryParseInt32Invariant(value, out var res))
-			{
-				if (res >= 0 && res < BoxedInts.Length)
-					return BoxedInts[res];
+			if (Exts.TryParseIntegerInvariant(value, out var res))
 				return res;
-			}
-
 			return InvalidValueAction(value, fieldType, fieldName);
 		}

@@ -165,7 +159,7 @@ namespace OpenRA
 		static object ParseColor(string fieldName, Type fieldType, string value, MemberInfo field)
 		{
 			if (value != null && Color.TryParse(value, out var color))
-				return color;
+					return color;

 			return InvalidValueAction(value, fieldType, fieldName);
 		}
@@ -196,11 +190,11 @@ namespace OpenRA
 			if (value != null)
 			{
 				var parts = value.Split(SplitComma);
-				if (parts.Length == 3
-					&& WDist.TryParse(parts[0], out var rx)
-					&& WDist.TryParse(parts[1], out var ry)
-					&& WDist.TryParse(parts[2], out var rz))
-					return new WVec(rx, ry, rz);
+				if (parts.Length == 3)
+				{
+					if (WDist.TryParse(parts[0], out var rx) && WDist.TryParse(parts[1], out var ry) && WDist.TryParse(parts[2], out var rz))
+						return new WVec(rx, ry, rz);
+				}
 			}

 			return InvalidValueAction(value, fieldType, fieldName);
@@ -220,8 +214,8 @@ namespace OpenRA
 				for (var i = 0; i < vecs.Length; ++i)
 				{
 					if (WDist.TryParse(parts[3 * i], out var rx)
-						&& WDist.TryParse(parts[3 * i + 1], out var ry)
-						&& WDist.TryParse(parts[3 * i + 2], out var rz))
+							&& WDist.TryParse(parts[3 * i + 1], out var ry)
+							&& WDist.TryParse(parts[3 * i + 2], out var rz))
 						vecs[i] = new WVec(rx, ry, rz);
 				}

@@ -236,11 +230,13 @@ namespace OpenRA
 			if (value != null)
 			{
 				var parts = value.Split(SplitComma);
-				if (parts.Length == 3
-					&& WDist.TryParse(parts[0], out var rx)
-					&& WDist.TryParse(parts[1], out var ry)
-					&& WDist.TryParse(parts[2], out var rz))
-					return new WPos(rx, ry, rz);
+				if (parts.Length == 3)
+				{
+					if (WDist.TryParse(parts[0], out var rx)
+						&& WDist.TryParse(parts[1], out var ry)
+						&& WDist.TryParse(parts[2], out var rz))
+						return new WPos(rx, ry, rz);
+				}
 			}

 			return InvalidValueAction(value, fieldType, fieldName);
@@ -248,7 +244,7 @@ namespace OpenRA

 		static object ParseWAngle(string fieldName, Type fieldType, string value, MemberInfo field)
 		{
-			if (Exts.TryParseInt32Invariant(value, out var res))
+			if (Exts.TryParseIntegerInvariant(value, out var res))
 				return new WAngle(res);
 			return InvalidValueAction(value, fieldType, fieldName);
 		}
@@ -258,11 +254,13 @@ namespace OpenRA
 			if (value != null)
 			{
 				var parts = value.Split(SplitComma);
-				if (parts.Length == 3
-					&& Exts.TryParseInt32Invariant(parts[0], out var rr)
-					&& Exts.TryParseInt32Invariant(parts[1], out var rp)
-					&& Exts.TryParseInt32Invariant(parts[2], out var ry))
-					return new WRot(new WAngle(rr), new WAngle(rp), new WAngle(ry));
+				if (parts.Length == 3)
+				{
+					if (Exts.TryParseIntegerInvariant(parts[0], out var rr)
+							&& Exts.TryParseIntegerInvariant(parts[1], out var rp)
+							&& Exts.TryParseIntegerInvariant(parts[2], out var ry))
+						return new WRot(new WAngle(rr), new WAngle(rp), new WAngle(ry));
+				}
 			}

 			return InvalidValueAction(value, fieldType, fieldName);
@@ -275,33 +273,10 @@ namespace OpenRA
 				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
 				if (parts.Length == 3)
 					return new CPos(
-						Exts.ParseInt32Invariant(parts[0]),
-						Exts.ParseInt32Invariant(parts[1]),
-						Exts.ParseByteInvariant(parts[2]));
-				return new CPos(Exts.ParseInt32Invariant(parts[0]), Exts.ParseInt32Invariant(parts[1]));
-			}
-
-			return InvalidValueAction(value, fieldType, fieldName);
-		}
-
-		static object ParseCPosArray(string fieldName, Type fieldType, string value, MemberInfo field)
-		{
-			if (value != null)
-			{
-				var parts = value.Split(SplitComma);
-
-				if (parts.Length % 2 != 0)
-					return InvalidValueAction(value, fieldType, fieldName);
-
-				var vecs = new CPos[parts.Length / 2];
-				for (var i = 0; i < vecs.Length; i++)
-				{
-					if (int.TryParse(parts[2 * i], out var rx)
-							&& int.TryParse(parts[2 * i + 1], out var ry))
-						vecs[i] = new CPos(rx, ry);
-				}
-
-				return vecs;
+						Exts.ParseIntegerInvariant(parts[0]),
+						Exts.ParseIntegerInvariant(parts[1]),
+						Exts.ParseByte(parts[2]));
+				return new CPos(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
 			}

 			return InvalidValueAction(value, fieldType, fieldName);
@@ -312,7 +287,7 @@ namespace OpenRA
 			if (value != null)
 			{
 				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
-				return new CVec(Exts.ParseInt32Invariant(parts[0]), Exts.ParseInt32Invariant(parts[1]));
+				return new CVec(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
 			}

 			return InvalidValueAction(value, fieldType, fieldName);
@@ -390,7 +365,7 @@ namespace OpenRA
 		static object ParseBool(string fieldName, Type fieldType, string value, MemberInfo field)
 		{
 			if (bool.TryParse(value.ToLowerInvariant(), out var result))
-				return result ? BoxedTrue : BoxedFalse;
+				return result;

 			return InvalidValueAction(value, fieldType, fieldName);
 		}
@@ -405,7 +380,7 @@ namespace OpenRA

 				var ints = new int2[parts.Length / 2];
 				for (var i = 0; i < ints.Length; i++)
-					ints[i] = new int2(Exts.ParseInt32Invariant(parts[2 * i]), Exts.ParseInt32Invariant(parts[2 * i + 1]));
+					ints[i] = new int2(Exts.ParseIntegerInvariant(parts[2 * i]), Exts.ParseIntegerInvariant(parts[2 * i + 1]));

 				return ints;
 			}
@@ -418,7 +393,7 @@ namespace OpenRA
 			if (value != null)
 			{
 				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
-				return new Size(Exts.ParseInt32Invariant(parts[0]), Exts.ParseInt32Invariant(parts[1]));
+				return new Size(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
 			}

 			return InvalidValueAction(value, fieldType, fieldName);
@@ -432,7 +407,7 @@ namespace OpenRA
 				if (parts.Length != 2)
 					return InvalidValueAction(value, fieldType, fieldName);

-				return new int2(Exts.ParseInt32Invariant(parts[0]), Exts.ParseInt32Invariant(parts[1]));
+				return new int2(Exts.ParseIntegerInvariant(parts[0]), Exts.ParseIntegerInvariant(parts[1]));
 			}

 			return InvalidValueAction(value, fieldType, fieldName);
@@ -480,10 +455,10 @@ namespace OpenRA
 			{
 				var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
 				return new Rectangle(
-					Exts.ParseInt32Invariant(parts[0]),
-					Exts.ParseInt32Invariant(parts[1]),
-					Exts.ParseInt32Invariant(parts[2]),
-					Exts.ParseInt32Invariant(parts[3]));
+					Exts.ParseIntegerInvariant(parts[0]),
+					Exts.ParseIntegerInvariant(parts[1]),
+					Exts.ParseIntegerInvariant(parts[2]),
+					Exts.ParseIntegerInvariant(parts[3]));
 			}

 			return InvalidValueAction(value, fieldType, fieldName);
@@ -498,11 +473,11 @@ namespace OpenRA

 		static object ParseHashSetOrList(string fieldName, Type fieldType, string value, MiniYaml yaml, MemberInfo field)
 		{
+			var set = Activator.CreateInstance(fieldType);
 			if (value == null)
-				return Activator.CreateInstance(fieldType);
+				return set;

 			var parts = value.Split(SplitComma, StringSplitOptions.RemoveEmptyEntries);
-			var set = Activator.CreateInstance(fieldType, parts.Length);
 			var arguments = fieldType.GetGenericArguments();
 			var addMethod = fieldType.GetMethod(nameof(List<object>.Add), arguments);
 			var addArgs = new object[1];
@@ -517,10 +492,7 @@ namespace OpenRA

 		static object ParseDictionary(string fieldName, Type fieldType, string value, MiniYaml yaml, MemberInfo field)
 		{
-			if (yaml == null)
-				return Activator.CreateInstance(fieldType);
-
-			var dict = Activator.CreateInstance(fieldType, yaml.Nodes.Length);
+			var dict = Activator.CreateInstance(fieldType);
 			var arguments = fieldType.GetGenericArguments();
 			var addMethod = fieldType.GetMethod(nameof(Dictionary<object, object>.Add), arguments);
 			var addArgs = new object[2];
@@ -551,7 +523,7 @@ namespace OpenRA
 			if (string.IsNullOrEmpty(value))
 				return null;

-			var innerType = fieldType.GetGenericArguments()[0];
+			var innerType = fieldType.GetGenericArguments().First();
 			var innerValue = GetValue("Nullable<T>", innerType, value, field);
 			return fieldType.GetConstructor(new[] { innerType }).Invoke(new[] { innerValue });
 		}
@@ -559,7 +531,7 @@ namespace OpenRA
 		public static void Load(object self, MiniYaml my)
 		{
 			var loadInfo = TypeLoadInfo[self.GetType()];
-			List<string> missing = null;
+			var missing = new List<string>();

 			Dictionary<string, MiniYaml> md = null;

@@ -567,14 +539,14 @@ namespace OpenRA
 			{
 				object val;

-				md ??= my.ToDictionary();
+				if (md == null)
+					md = my.ToDictionary();
 				if (fli.Loader != null)
 				{
 					if (!fli.Attribute.Required || md.ContainsKey(fli.YamlName))
 						val = fli.Loader(my);
 					else
 					{
-						missing ??= new List<string>();
 						missing.Add(fli.YamlName);
 						continue;
 					}
@@ -584,11 +556,7 @@ namespace OpenRA
 					if (!TryGetValueFromYaml(fli.YamlName, fli.Field, md, out val))
 					{
 						if (fli.Attribute.Required)
-						{
-							missing ??= new List<string>();
 							missing.Add(fli.YamlName);
-						}
-
 						continue;
 					}
 				}
@@ -596,7 +564,7 @@ namespace OpenRA
 				fli.Field.SetValue(self, val);
 			}

-			if (missing != null)
+			if (missing.Count > 0)
 				throw new MissingFieldsException(missing.ToArray());
 		}

@@ -657,17 +625,12 @@ namespace OpenRA

 		public static object GetValue(string fieldName, Type fieldType, string value, MemberInfo field)
 		{
-			return GetValue(fieldName, fieldType, value, null, field);
+			return GetValue(fieldName, fieldType, new MiniYaml(value), field);
 		}

 		public static object GetValue(string fieldName, Type fieldType, MiniYaml yaml, MemberInfo field)
 		{
-			return GetValue(fieldName, fieldType, yaml.Value, yaml, field);
-		}
-
-		static object GetValue(string fieldName, Type fieldType, string value, MiniYaml yaml, MemberInfo field)
-		{
-			value = value?.Trim();
+			var value = yaml.Value?.Trim();
 			if (fieldType.IsGenericType)
 			{
 				if (GenericTypeParsers.TryGetValue(fieldType.GetGenericTypeDefinition(), out var parseFuncGeneric))
@@ -791,7 +754,7 @@ namespace OpenRA
 		[AttributeUsage(AttributeTargets.Field)]
 		public class SerializeAttribute : Attribute
 		{
-			public static readonly SerializeAttribute Default = new(true);
+			public static readonly SerializeAttribute Default = new SerializeAttribute(true);

 			public bool IsDefault => this == Default;

--- a/OpenRA.Game/FieldSaver.cs
+++ b/OpenRA.Game/FieldSaver.cs
@@ -15,7 +15,6 @@ using System.ComponentModel;
 using System.Globalization;
 using System.Linq;
 using System.Reflection;
-using System.Text;
 using OpenRA.Primitives;

 namespace OpenRA
@@ -59,7 +58,7 @@ namespace OpenRA

 			return new MiniYaml(
 				null,
-				fields.Select(info => new MiniYamlNode(info.YamlName, FormatValue(o, info.Field))));
+				fields.Select(info => new MiniYamlNode(info.YamlName, FormatValue(o, info.Field))).ToList());
 		}

 		public static MiniYamlNode SaveField(object o, string field)
@@ -85,7 +84,7 @@ namespace OpenRA
 			// This is only for documentation generation
 			if (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Dictionary<,>))
 			{
-				var result = new StringBuilder();
+				var result = "";
 				var dict = (System.Collections.IDictionary)v;
 				foreach (var kvp in dict)
 				{
@@ -95,10 +94,10 @@ namespace OpenRA
 					var formattedKey = FormatValue(key);
 					var formattedValue = FormatValue(value);

-					result.Append($"{formattedKey}: {formattedValue}{Environment.NewLine}");
+					result += $"{formattedKey}: {formattedValue}{Environment.NewLine}";
 				}

-				return result.ToString();
+				return result;
 			}

 			if (v is DateTime d)
--- a/OpenRA.Game/FileFormats/Png.cs
+++ b/OpenRA.Game/FileFormats/Png.cs
@@ -16,7 +16,6 @@ using System.Linq;
 using System.Net;
 using System.Text;
 using ICSharpCode.SharpZipLib.Checksum;
-using ICSharpCode.SharpZipLib.Zip.Compression;
 using ICSharpCode.SharpZipLib.Zip.Compression.Streams;
 using OpenRA.Graphics;
 using OpenRA.Primitives;
@@ -32,7 +31,7 @@ namespace OpenRA.FileFormats
 		public Color[] Palette { get; }
 		public byte[] Data { get; }
 		public SpriteFrameType Type { get; }
-		public Dictionary<string, string> EmbeddedData = new();
+		public Dictionary<string, string> EmbeddedData = new Dictionary<string, string>();

 		public int PixelStride => Type == SpriteFrameType.Indexed8 ? 1 : Type == SpriteFrameType.Rgb24 ? 3 : 4;

@@ -46,13 +45,12 @@ namespace OpenRA.FileFormats
 			var data = new List<byte>();
 			Type = SpriteFrameType.Rgba32;

-			byte bitDepth = 8;
 			while (true)
 			{
 				var length = IPAddress.NetworkToHostOrder(s.ReadInt32());
-				var type = s.ReadASCII(4);
+				var type = Encoding.UTF8.GetString(s.ReadBytes(4));
 				var content = s.ReadBytes(length);
-				s.ReadInt32(); // crc
+				/*var crc = */s.ReadInt32();

 				if (!headerParsed && type != "IHDR")
 					throw new InvalidDataException("Invalid PNG file - header does not appear first.");
@@ -68,8 +66,8 @@ namespace OpenRA.FileFormats
 							Width = IPAddress.NetworkToHostOrder(ms.ReadInt32());
 							Height = IPAddress.NetworkToHostOrder(ms.ReadInt32());

-							bitDepth = ms.ReadUInt8();
-							var colorType = (PngColorType)ms.ReadUInt8();
+							var bitDepth = ms.ReadUInt8();
+							var colorType = (PngColorType)ms.ReadByte();
 							if (IsPaletted(bitDepth, colorType))
 								Type = SpriteFrameType.Indexed8;
 							else if (colorType == PngColorType.Color)
@@ -77,9 +75,9 @@ namespace OpenRA.FileFormats

 							Data = new byte[Width * Height * PixelStride];

-							var compression = ms.ReadUInt8();
-							ms.ReadUInt8(); // filter
-							var interlace = ms.ReadUInt8();
+							var compression = ms.ReadByte();
+							/*var filter = */ms.ReadByte();
+							var interlace = ms.ReadByte();

 							if (compression != 0)
 								throw new InvalidDataException("Compression method not supported");
@@ -94,10 +92,10 @@ namespace OpenRA.FileFormats

 						case "PLTE":
 						{
-							Palette = new Color[length / 3];
-							for (var i = 0; i < Palette.Length; i++)
+							Palette = new Color[256];
+							for (var i = 0; i < length / 3; i++)
 							{
-								var r = ms.ReadUInt8(); var g = ms.ReadUInt8(); var b = ms.ReadUInt8();
+								var r = ms.ReadByte(); var g = ms.ReadByte(); var b = ms.ReadByte();
 								Palette[i] = Color.FromArgb(r, g, b);
 							}

@@ -110,7 +108,7 @@ namespace OpenRA.FileFormats
 								throw new InvalidDataException("Non-Palette indexed PNG are not supported.");

 							for (var i = 0; i < length; i++)
-								Palette[i] = Color.FromArgb(ms.ReadUInt8(), Palette[i]);
+								Palette[i] = Color.FromArgb(ms.ReadByte(), Palette[i]);

 							break;
 						}
@@ -138,77 +136,22 @@ namespace OpenRA.FileFormats
 								{
 									var pxStride = PixelStride;
 									var rowStride = Width * pxStride;
-									var pixelsPerByte = 8 / bitDepth;
-									var sourceRowStride = Exts.IntegerDivisionRoundingAwayFromZero(rowStride, pixelsPerByte);

-									Span<byte> prevLine = new byte[rowStride];
+									var prevLine = new byte[rowStride];
 									for (var y = 0; y < Height; y++)
 									{
-										var filter = (PngFilter)ds.ReadUInt8();
-										ds.ReadBytes(Data, y * rowStride, sourceRowStride);
-										var line = Data.AsSpan(y * rowStride, rowStride);
+										var filter = (PngFilter)ds.ReadByte();
+										var line = ds.ReadBytes(rowStride);

-										// If the source has a bit depth of 1, 2 or 4 it packs multiple pixels per byte.
-										// Unpack to bit depth of 8, yielding 1 pixel per byte.
-										// This makes life easier for consumers of palleted data.
-										if (bitDepth < 8)
-										{
-											var mask = 0xFF >> (8 - bitDepth);
-											for (var i = sourceRowStride - 1; i >= 0; i--)
-											{
-												var packed = line[i];
-												for (var j = 0; j < pixelsPerByte; j++)
-												{
-													var dest = i * pixelsPerByte + j;
-													if (dest < line.Length) // Guard against last byte being only partially packed
-														line[dest] = (byte)(packed >> (8 - (j + 1) * bitDepth) & mask);
-												}
-											}
-										}
+										for (var i = 0; i < rowStride; i++)
+											line[i] = i < pxStride
+												? UnapplyFilter(filter, line[i], 0, prevLine[i], 0)
+												: UnapplyFilter(filter, line[i], line[i - pxStride], prevLine[i], prevLine[i - pxStride]);

-										switch (filter)
-										{
-											case PngFilter.None:
-												break;
-											case PngFilter.Sub:
-												for (var i = pxStride; i < rowStride; i++)
-													line[i] += line[i - pxStride];
-												break;
-											case PngFilter.Up:
-												for (var i = 0; i < rowStride; i++)
-													line[i] += prevLine[i];
-												break;
-											case PngFilter.Average:
-												for (var i = 0; i < pxStride; i++)
-													line[i] += Average(0, prevLine[i]);
-												for (var i = pxStride; i < rowStride; i++)
-													line[i] += Average(line[i - pxStride], prevLine[i]);
-												break;
-											case PngFilter.Paeth:
-												for (var i = 0; i < pxStride; i++)
-													line[i] += Paeth(0, prevLine[i], 0);
-												for (var i = pxStride; i < rowStride; i++)
-													line[i] += Paeth(line[i - pxStride], prevLine[i], prevLine[i - pxStride]);
-												break;
-											default:
-												throw new InvalidOperationException("Unsupported Filter");
-										}
+										Array.Copy(line, 0, Data, y * rowStride, rowStride);

 										prevLine = line;
 									}
-
-									static byte Average(byte a, byte b) => (byte)((a + b) / 2);
-
-									static byte Paeth(byte a, byte b, byte c)
-									{
-										var p = a + b - c;
-										var pa = Math.Abs(p - a);
-										var pb = Math.Abs(p - b);
-										var pc = Math.Abs(p - c);
-
-										return (pa <= pb && pa <= pc) ? a :
-											(pb <= pc) ? b : c;
-									}
 								}
 							}

@@ -285,13 +228,38 @@ namespace OpenRA.FileFormats
 			return isPng;
 		}

+		static byte UnapplyFilter(PngFilter f, byte x, byte a, byte b, byte c)
+		{
+			switch (f)
+			{
+				case PngFilter.None: return x;
+				case PngFilter.Sub: return (byte)(x + a);
+				case PngFilter.Up: return (byte)(x + b);
+				case PngFilter.Average: return (byte)(x + (a + b) / 2);
+				case PngFilter.Paeth: return (byte)(x + Paeth(a, b, c));
+				default:
+					throw new InvalidOperationException("Unsupported Filter");
+			}
+		}
+
+		static byte Paeth(byte a, byte b, byte c)
+		{
+			var p = a + b - c;
+			var pa = Math.Abs(p - a);
+			var pb = Math.Abs(p - b);
+			var pc = Math.Abs(p - c);
+
+			return (pa <= pb && pa <= pc) ? a :
+				(pb <= pc) ? b : c;
+		}
+
 		[Flags]
-		enum PngColorType : byte { Indexed = 1, Color = 2, Alpha = 4 }
-		enum PngFilter : byte { None, Sub, Up, Average, Paeth }
+		enum PngColorType { Indexed = 1, Color = 2, Alpha = 4 }
+		enum PngFilter { None, Sub, Up, Average, Paeth }

 		static bool IsPaletted(byte bitDepth, PngColorType colorType)
 		{
-			if (bitDepth <= 8 && colorType == (PngColorType.Indexed | PngColorType.Color))
+			if (bitDepth == 8 && colorType == (PngColorType.Indexed | PngColorType.Color))
 				return true;

 			if (bitDepth == 8 && colorType == (PngColorType.Color | PngColorType.Alpha))
@@ -303,16 +271,16 @@ namespace OpenRA.FileFormats
 			throw new InvalidDataException("Unknown pixel format");
 		}

-		static void WritePngChunk(Stream output, string type, Stream input)
+		void WritePngChunk(Stream output, string type, Stream input)
 		{
 			input.Position = 0;

 			var typeBytes = Encoding.ASCII.GetBytes(type);
 			output.Write(IPAddress.HostToNetworkOrder((int)input.Length));
-			output.Write(typeBytes);
+			output.WriteArray(typeBytes);

 			var data = input.ReadAllBytes();
-			output.Write(data);
+			output.WriteArray(data);

 			var crc32 = new Crc32();
 			crc32.Update(typeBytes);
@@ -324,7 +292,7 @@ namespace OpenRA.FileFormats
 		{
 			using (var output = new MemoryStream())
 			{
-				output.Write(Signature);
+				output.WriteArray(Signature);
 				using (var header = new MemoryStream())
 				{
 					header.Write(IPAddress.HostToNetworkOrder(Width));
@@ -372,14 +340,13 @@ namespace OpenRA.FileFormats

 				using (var data = new MemoryStream())
 				{
-					using (var compressed = new DeflaterOutputStream(data, new Deflater(Deflater.BEST_COMPRESSION)))
+					using (var compressed = new DeflaterOutputStream(data))
 					{
 						var rowStride = Width * PixelStride;
 						for (var y = 0; y < Height; y++)
 						{
-							// Assuming no filtering for simplicity
-							const byte FilterType = 0;
-							compressed.WriteByte(FilterType);
+							// Write uncompressed scanlines for simplicity
+							compressed.WriteByte(0);
 							compressed.Write(Data, y * rowStride, rowStride);
 						}

@@ -394,7 +361,7 @@ namespace OpenRA.FileFormats
 				{
 					using (var text = new MemoryStream())
 					{
-						text.Write(Encoding.ASCII.GetBytes(kv.Key + (char)0 + kv.Value));
+						text.WriteArray(Encoding.ASCII.GetBytes(kv.Key + (char)0 + kv.Value));
 						WritePngChunk(output, "tEXt", text);
 					}
 				}
--- a/OpenRA.Game/FileFormats/ReplayMetadata.cs
+++ b/OpenRA.Game/FileFormats/ReplayMetadata.cs
@@ -47,8 +47,8 @@ namespace OpenRA.FileFormats
 				throw new NotSupportedException($"Metadata version {version} is not supported");

 			// Read game info (max 100K limit as a safeguard against corrupted files)
-			var data = fs.ReadLengthPrefixedString(Encoding.UTF8, 1024 * 100);
-			GameInfo = GameInformation.Deserialize(data, path);
+			var data = fs.ReadString(Encoding.UTF8, 1024 * 100);
+			GameInfo = GameInformation.Deserialize(data);
 		}

 		public void Write(BinaryWriter writer)
@@ -62,7 +62,7 @@ namespace OpenRA.FileFormats
 			{
 				// Write lobby info data
 				writer.Flush();
-				dataLength += writer.BaseStream.WriteLengthPrefixedString(Encoding.UTF8, GameInfo.Serialize());
+				dataLength += writer.BaseStream.WriteString(Encoding.UTF8, GameInfo.Serialize());
 			}

 			// Write total length & end marker
--- a/OpenRA.Game/FileSystem/FileSystem.cs
+++ b/OpenRA.Game/FileSystem/FileSystem.cs
@@ -29,16 +29,16 @@ namespace OpenRA.FileSystem
 	public class FileSystem : IReadOnlyFileSystem
 	{
 		public IEnumerable<IReadOnlyPackage> MountedPackages => mountedPackages.Keys;
-		readonly Dictionary<IReadOnlyPackage, int> mountedPackages = new();
-		readonly Dictionary<string, IReadOnlyPackage> explicitMounts = new();
+		readonly Dictionary<IReadOnlyPackage, int> mountedPackages = new Dictionary<IReadOnlyPackage, int>();
+		readonly Dictionary<string, IReadOnlyPackage> explicitMounts = new Dictionary<string, IReadOnlyPackage>();
 		readonly string modID;

 		// Mod packages that should not be disposed
-		readonly List<IReadOnlyPackage> modPackages = new();
+		readonly List<IReadOnlyPackage> modPackages = new List<IReadOnlyPackage>();
 		readonly IReadOnlyDictionary<string, Manifest> installedMods;
 		readonly IPackageLoader[] packageLoaders;

-		Cache<string, List<IReadOnlyPackage>> fileIndex = new(_ => new List<IReadOnlyPackage>());
+		Cache<string, List<IReadOnlyPackage>> fileIndex = new Cache<string, List<IReadOnlyPackage>>(_ => new List<IReadOnlyPackage>());

 		public FileSystem(string modID, IReadOnlyDictionary<string, Manifest> installedMods, IPackageLoader[] packageLoaders)
 		{
@@ -83,16 +83,16 @@ namespace OpenRA.FileSystem

 		public void Mount(string name, string explicitName = null)
 		{
-			var optional = name.StartsWith('~');
+			var optional = name.StartsWith("~", StringComparison.Ordinal);
 			if (optional)
-				name = name[1..];
+				name = name.Substring(1);

 			try
 			{
 				IReadOnlyPackage package;
-				if (name.StartsWith('$'))
+				if (name.StartsWith("$", StringComparison.Ordinal))
 				{
-					name = name[1..];
+					name = name.Substring(1);

 					if (!installedMods.TryGetValue(name, out var mod))
 						throw new InvalidOperationException($"Could not load mod '{name}'. Available mods: {installedMods.Keys.JoinWith(", ")}");
@@ -109,8 +109,10 @@ namespace OpenRA.FileSystem

 				Mount(package, explicitName);
 			}
-			catch when (optional)
+			catch
 			{
+				if (!optional)
+					throw;
 			}
 		}

@@ -159,7 +161,9 @@ namespace OpenRA.FileSystem
 					explicitMounts.Remove(key);

 				// Mod packages aren't owned by us, so we shouldn't dispose them
-				if (!modPackages.Remove(package))
+				if (modPackages.Contains(package))
+					modPackages.Remove(package);
+				else
 					package.Dispose();
 			}
 			else
@@ -186,12 +190,6 @@ namespace OpenRA.FileSystem
 			UnmountAll();
 			foreach (var kv in manifest.Packages)
 				Mount(kv.Key, kv.Value);
-
-			mountedPackages.TrimExcess();
-			explicitMounts.TrimExcess();
-			modPackages.TrimExcess();
-			foreach (var packages in fileIndex.Values)
-				packages.TrimExcess();
 		}

 		Stream GetFromCache(string filename)
@@ -213,9 +211,9 @@ namespace OpenRA.FileSystem
 		public bool TryGetPackageContaining(string path, out IReadOnlyPackage package, out string filename)
 		{
 			var explicitSplit = path.IndexOf('|');
-			if (explicitSplit > 0 && explicitMounts.TryGetValue(path[..explicitSplit], out package))
+			if (explicitSplit > 0 && explicitMounts.TryGetValue(path.Substring(0, explicitSplit), out package))
 			{
-				filename = path[(explicitSplit + 1)..];
+				filename = path.Substring(explicitSplit + 1);
 				return true;
 			}

@@ -228,11 +226,14 @@ namespace OpenRA.FileSystem
 		public bool TryOpen(string filename, out Stream s)
 		{
 			var explicitSplit = filename.IndexOf('|');
-			if (explicitSplit > 0 && explicitMounts.TryGetValue(filename[..explicitSplit], out var explicitPackage))
+			if (explicitSplit > 0)
 			{
-				s = explicitPackage.GetStream(filename[(explicitSplit + 1)..]);
-				if (s != null)
-					return true;
+				if (explicitMounts.TryGetValue(filename.Substring(0, explicitSplit), out var explicitPackage))
+				{
+					s = explicitPackage.GetStream(filename.Substring(explicitSplit + 1));
+					if (s != null)
+						return true;
+				}
 			}

 			s = GetFromCache(filename);
@@ -261,16 +262,16 @@ namespace OpenRA.FileSystem
 		public bool Exists(string filename)
 		{
 			var explicitSplit = filename.IndexOf('|');
-			if (explicitSplit > 0 &&
-				explicitMounts.TryGetValue(filename[..explicitSplit], out var explicitPackage) &&
-				explicitPackage.Contains(filename[(explicitSplit + 1)..]))
-				return true;
+			if (explicitSplit > 0)
+				if (explicitMounts.TryGetValue(filename.Substring(0, explicitSplit), out var explicitPackage))
+					if (explicitPackage.Contains(filename.Substring(explicitSplit + 1)))
+						return true;

 			return fileIndex.ContainsKey(filename);
 		}

 		/// <summary>
-		/// Returns true if the given filename references an external mod via an explicit mount.
+		/// Returns true if the given filename references an external mod via an explicit mount
 		/// </summary>
 		public bool IsExternalModFile(string filename)
 		{
@@ -278,7 +279,7 @@ namespace OpenRA.FileSystem
 			if (explicitSplit < 0)
 				return false;

-			if (!explicitMounts.TryGetValue(filename[..explicitSplit], out var explicitPackage))
+			if (!explicitMounts.TryGetValue(filename.Substring(0, explicitSplit), out var explicitPackage))
 				return false;

 			if (installedMods[modID].Package == explicitPackage)
@@ -294,21 +295,21 @@ namespace OpenRA.FileSystem
 		public static string ResolveAssemblyPath(string path, Manifest manifest, InstalledMods installedMods)
 		{
 			var explicitSplit = path.IndexOf('|');
-			if (explicitSplit > 0 && !path.StartsWith('^'))
+			if (explicitSplit > 0 && !path.StartsWith("^"))
 			{
-				var parent = path[..explicitSplit];
-				var filename = path[(explicitSplit + 1)..];
+				var parent = path.Substring(0, explicitSplit);
+				var filename = path.Substring(explicitSplit + 1);

 				var parentPath = manifest.Packages.FirstOrDefault(kv => kv.Value == parent).Key;
 				if (parentPath == null)
 					return null;

-				if (parentPath.StartsWith('$'))
+				if (parentPath.StartsWith("$", StringComparison.Ordinal))
 				{
-					if (!installedMods.TryGetValue(parentPath[1..], out var mod))
+					if (!installedMods.TryGetValue(parentPath.Substring(1), out var mod))
 						return null;

-					if (mod.Package is not Folder)
+					if (!(mod.Package is Folder))
 						return null;

 					path = Path.Combine(mod.Package.Name, filename);
@@ -328,7 +329,7 @@ namespace OpenRA.FileSystem
 			if (resolved == null)
 				return null;

-			foreach (var name in path[resolved.Length..].Split(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar))
+			foreach (var name in path.Substring(resolved.Length).Split(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar))
 			{
 				// Filter out paths of the form /foo/bar/./baz
 				if (name == ".")
--- a/OpenRA.Game/FileSystem/Folder.cs
+++ b/OpenRA.Game/FileSystem/Folder.cs
@@ -18,22 +18,24 @@ namespace OpenRA.FileSystem
 {
 	public sealed class Folder : IReadWritePackage
 	{
-		public string Name { get; }
+		readonly string path;

 		public Folder(string path)
 		{
-			Name = path;
+			this.path = path;
 			if (!Directory.Exists(path))
 				Directory.CreateDirectory(path);
 		}

+		public string Name => path;
+
 		public IEnumerable<string> Contents
 		{
 			get
 			{
 				// Order may vary on different file systems and it matters for hashing.
-				return Directory.GetFiles(Name, "*", SearchOption.TopDirectoryOnly)
-					.Concat(Directory.GetDirectories(Name))
+				return Directory.GetFiles(path, "*", SearchOption.TopDirectoryOnly)
+					.Concat(Directory.GetDirectories(path))
 					.Select(Path.GetFileName)
 					.OrderBy(f => f);
 			}
@@ -41,18 +43,14 @@ namespace OpenRA.FileSystem

 		public Stream GetStream(string filename)
 		{
-			var combined = Path.Combine(Name, filename);
-			if (!File.Exists(combined))
-				return null;
-
-			try { return File.OpenRead(combined); }
+			try { return File.OpenRead(Path.Combine(path, filename)); }
 			catch { return null; }
 		}

 		public bool Contains(string filename)
 		{
-			var combined = Path.Combine(Name, filename);
-			return combined.StartsWith(Name, StringComparison.Ordinal) && File.Exists(combined);
+			var combined = Path.Combine(path, filename);
+			return combined.StartsWith(path, StringComparison.Ordinal) && File.Exists(combined);
 		}

 		public IReadOnlyPackage OpenPackage(string filename, FileSystem context)
@@ -84,7 +82,7 @@ namespace OpenRA.FileSystem
 			// in FileSystem.OpenPackage.  Their internal name therefore contains the
 			// full parent path too.  We need to be careful to not add a second path
 			// prefix to these hacked packages.
-			var filePath = filename.StartsWith(Name, StringComparison.Ordinal) ? filename : Path.Combine(Name, filename);
+			var filePath = filename.StartsWith(path) ? filename : Path.Combine(path, filename);

 			Directory.CreateDirectory(Path.GetDirectoryName(filePath));
 			using (var s = File.Create(filePath))
@@ -98,7 +96,7 @@ namespace OpenRA.FileSystem
 			// in FileSystem.OpenPackage.  Their internal name therefore contains the
 			// full parent path too.  We need to be careful to not add a second path
 			// prefix to these hacked packages.
-			var filePath = filename.StartsWith(Name, StringComparison.Ordinal) ? filename : Path.Combine(Name, filename);
+			var filePath = filename.StartsWith(path) ? filename : Path.Combine(path, filename);
 			if (Directory.Exists(filePath))
 				Directory.Delete(filePath, true);
 			else if (File.Exists(filePath))
--- a/OpenRA.Game/FileSystem/ZipFile.cs
+++ b/OpenRA.Game/FileSystem/ZipFile.cs
@@ -19,9 +19,9 @@ namespace OpenRA.FileSystem
 {
 	public class ZipFileLoader : IPackageLoader
 	{
-		const uint ZipSignature = 0x04034b50;
+		static readonly uint ZipSignature = 0x04034b50;

-		public class ReadOnlyZipFile : IReadOnlyPackage
+		class ReadOnlyZipFile : IReadOnlyPackage
 		{
 			public string Name { get; protected set; }
 			protected ZipFile pkg;
@@ -55,8 +55,7 @@ namespace OpenRA.FileSystem
 				get
 				{
 					foreach (ZipEntry entry in pkg)
-						if (entry.IsFile)
-							yield return entry.Name;
+						yield return entry.Name;
 				}
 			}

@@ -68,7 +67,6 @@ namespace OpenRA.FileSystem
 			public void Dispose()
 			{
 				pkg?.Close();
-				GC.SuppressFinalize(this);
 			}

 			public IReadOnlyPackage OpenPackage(string filename, FileSystem context)
@@ -94,9 +92,9 @@ namespace OpenRA.FileSystem
 			}
 		}

-		public sealed class ReadWriteZipFile : ReadOnlyZipFile, IReadWritePackage
+		sealed class ReadWriteZipFile : ReadOnlyZipFile, IReadWritePackage
 		{
-			readonly MemoryStream pkgStream = new();
+			readonly MemoryStream pkgStream = new MemoryStream();

 			public ReadWriteZipFile(string filename, bool create = false)
 			{
@@ -118,7 +116,10 @@ namespace OpenRA.FileSystem

 			void Commit()
 			{
-				File.WriteAllBytes(Name, pkgStream.ToArray());
+				var pos = pkgStream.Position;
+				pkgStream.Position = 0;
+				File.WriteAllBytes(Name, pkgStream.ReadBytes((int)pkgStream.Length));
+				pkgStream.Position = pos;
 			}

 			public void Update(string filename, byte[] contents)
@@ -140,22 +141,23 @@ namespace OpenRA.FileSystem

 		sealed class ZipFolder : IReadOnlyPackage
 		{
-			public string Name { get; }
+			public string Name => path;
 			public ReadOnlyZipFile Parent { get; }
+			readonly string path;

 			public ZipFolder(ReadOnlyZipFile parent, string path)
 			{
-				if (path.EndsWith('/'))
-					path = path[..^1];
+				if (path.EndsWith("/", StringComparison.Ordinal))
+					path = path.Substring(0, path.Length - 1);

-				Name = path;
 				Parent = parent;
+				this.path = path;
 			}

 			public Stream GetStream(string filename)
 			{
 				// Zip files use '/' as a path separator
-				return Parent.GetStream(Name + '/' + filename);
+				return Parent.GetStream(path + '/' + filename);
 			}

 			public IEnumerable<string> Contents
@@ -164,9 +166,9 @@ namespace OpenRA.FileSystem
 				{
 					foreach (var entry in Parent.Contents)
 					{
-						if (entry.StartsWith(Name, StringComparison.Ordinal) && entry != Name)
+						if (entry.StartsWith(path, StringComparison.Ordinal) && entry != path)
 						{
-							var filename = entry[(Name.Length + 1)..];
+							var filename = entry.Substring(path.Length + 1);
 							var dirLevels = filename.Split('/').Count(c => !string.IsNullOrEmpty(c));
 							if (dirLevels == 1)
 								yield return filename;
@@ -177,18 +179,18 @@ namespace OpenRA.FileSystem

 			public bool Contains(string filename)
 			{
-				return Parent.Contains(Name + '/' + filename);
+				return Parent.Contains(path + '/' + filename);
 			}

 			public IReadOnlyPackage OpenPackage(string filename, FileSystem context)
 			{
-				return Parent.OpenPackage(Name + '/' + filename, context);
+				return Parent.OpenPackage(path + '/' + filename, context);
 			}

 			public void Dispose() { /* nothing to do */ }
 		}

-		sealed class StaticStreamDataSource : IStaticDataSource
+		class StaticStreamDataSource : IStaticDataSource
 		{
 			readonly Stream s;
 			public StaticStreamDataSource(Stream s)
--- a/OpenRA.Game/Game.cs
+++ b/OpenRA.Game/Game.cs
@@ -48,7 +48,7 @@ namespace OpenRA
 		internal static OrderManager OrderManager;
 		static Server.Server server;

-		public static MersenneTwister CosmeticRandom = new(); // not synced
+		public static MersenneTwister CosmeticRandom = new MersenneTwister(); // not synced

 		public static Renderer Renderer;
 		public static Sound Sound;
@@ -65,7 +65,7 @@ namespace OpenRA
 		{
 			var newConnection = new NetworkConnection(endpoint);
 			if (recordReplay)
-				newConnection.StartRecording(() => TimestampedFilename());
+				newConnection.StartRecording(() => { return TimestampedFilename(); });

 			var om = new OrderManager(newConnection);
 			JoinInner(om);
@@ -86,9 +86,8 @@ namespace OpenRA

 		static void JoinInner(OrderManager om)
 		{
-			// Refresh static classes before the game starts.
+			// Refresh TextNotificationsManager before the game starts.
 			TextNotificationsManager.Clear();
-			UnitOrders.Clear();

 			// HACK: The shellmap World and OrderManager are owned by the main menu's WorldRenderer instead of Game.
 			// This allows us to switch Game.OrderManager from the shellmap to the new network connection when joining
@@ -180,7 +179,6 @@ namespace OpenRA
 		}

 		public static event Action BeforeGameStart = () => { };
-		public static event Action AfterGameStart = () => { };
 		internal static void StartGame(string mapUID, WorldType type)
 		{
 			// Dispose of the old world before creating a new one.
@@ -189,8 +187,13 @@ namespace OpenRA
 			Cursor.SetCursor(null);
 			BeforeGameStart();

+			Map map;
+
+			using (new PerfTimer("PrepareMap"))
+				map = ModData.PrepareMap(mapUID);
+
 			using (new PerfTimer("NewWorld"))
-				OrderManager.World = new World(mapUID, ModData, OrderManager, type);
+				OrderManager.World = new World(ModData, map, OrderManager, type);

 			OrderManager.World.GameOver += FinishBenchmark;

@@ -224,12 +227,6 @@ namespace OpenRA
 			//   Much better to clean up now then to drop frames during gameplay for GC pauses.
 			GCSettings.LargeObjectHeapCompactionMode = GCLargeObjectHeapCompactionMode.CompactOnce;
 			GC.Collect();
-
-			// PostLoadComplete is designed for anything that should trigger at the very end of loading.
-			// e.g. audio notifications that the game is starting.
-			OrderManager.World.PostLoadComplete(worldRenderer);
-
-			AfterGameStart();
 		}

 		public static void RestartGame()
@@ -273,14 +270,15 @@ namespace OpenRA
 		{
 			OrderManager om = null;

-			void LobbyReady()
+			Action lobbyReady = null;
+			lobbyReady = () =>
 			{
-				LobbyInfoChanged -= LobbyReady;
+				LobbyInfoChanged -= lobbyReady;
 				foreach (var o in setupOrders)
 					om.IssueOrder(o);
-			}
+			};

-			LobbyInfoChanged += LobbyReady;
+			LobbyInfoChanged += lobbyReady;

 			om = JoinServer(CreateLocalServer(mapUID), "");
 		}
@@ -423,8 +421,8 @@ namespace OpenRA

 				// Sanitize input from platform-specific launchers
 				// Process.Start requires paths to not be quoted, even if they contain spaces
-				if (launchPath != null && launchPath[0] == '"' && launchPath.Last() == '"')
-					launchPath = launchPath[1..^1];
+				if (launchPath != null && launchPath.First() == '"' && launchPath.Last() == '"')
+					launchPath = launchPath.Substring(1, launchPath.Length - 2);

 				// Metadata registration requires an explicit launch path
 				if (launchPath != null)
@@ -531,11 +529,10 @@ namespace OpenRA
 				.Where(m => m.Status == MapStatus.Available && m.Visibility.HasFlag(MapVisibility.Shellmap))
 				.Select(m => m.Uid);

-			var shellmap = shellmaps.RandomOrDefault(CosmeticRandom);
-			if (shellmap == null)
+			if (!shellmaps.Any())
 				throw new InvalidDataException("No valid shellmaps available");

-			return shellmap;
+			return shellmaps.Random(CosmeticRandom);
 		}

 		public static void SwitchToExternalMod(ExternalMod mod, string[] launchArguments = null, Action onFailed = null)
@@ -572,7 +569,7 @@ namespace OpenRA

 		// Note: These delayed actions should only be used by widgets or disposing objects
 		// - things that depend on a particular world should be queuing them on the world actor.
-		static volatile ActionQueue delayedActions = new();
+		static volatile ActionQueue delayedActions = new ActionQueue();

 		public static void RunAfterTick(Action a) { delayedActions.Add(a, RunTime); }
 		public static void RunAfterDelay(int delayMilliseconds, Action a) { delayedActions.Add(a, RunTime + delayMilliseconds); }
@@ -590,7 +587,7 @@ namespace OpenRA
 				Log.Write("debug", "Taking screenshot " + path);

 				Renderer.SaveScreenshot(path);
-				TextNotificationsManager.Debug(TranslationProvider.GetString(SavedScreenshot, Translation.Arguments("filename", filename)));
+				TextNotificationsManager.Debug(ModData.Translation.GetString(SavedScreenshot, Translation.Arguments("filename", filename)));
 			}
 		}

@@ -609,10 +606,7 @@ namespace OpenRA

 			if (orderManager.LastTickTime.ShouldAdvance(tick))
 			{
-				if (orderManager.GameStarted && orderManager.LocalFrameNumber == 0)
-					PerfHistory.Reset(); // Remove history that occurred whilst the new game was loading.
-
-				using (var sample = new PerfSample("tick_time"))
+				using (new PerfSample("tick_time"))
 				{
 					orderManager.LastTickTime.AdvanceTickTime(tick);

@@ -621,15 +615,14 @@ namespace OpenRA
 					Sync.RunUnsynced(world, orderManager.TickImmediate);

 					if (world == null)
-					{
-						if (orderManager.GameStarted)
-							PerfHistory.Reset(); // Remove old history when a new game starts.
 						return;
-					}

 					if (orderManager.TryTick())
 					{
-						Sync.RunUnsynced(world, () => world.OrderGenerator.Tick(world));
+						Sync.RunUnsynced(world, () =>
+						{
+							world.OrderGenerator.Tick(world);
+						});

 						world.Tick();

@@ -679,7 +672,7 @@ namespace OpenRA
 				// Prepare renderables (i.e. render voxels) before calling BeginFrame
 				using (new PerfSample("render_prepare"))
 				{
-					worldRenderer?.BeginFrame();
+					Renderer.WorldModelRenderer.BeginFrame();

 					// World rendering is disabled while the loading screen is displayed
 					if (worldRenderer != null && !worldRenderer.World.IsLoadingGameSave)
@@ -689,7 +682,7 @@ namespace OpenRA
 					}

 					Ui.PrepareRenderables();
-					worldRenderer?.EndFrame();
+					Renderer.WorldModelRenderer.EndFrame();
 				}

 				// worldRenderer is null during the initial install/download screen
@@ -793,7 +786,7 @@ namespace OpenRA
 				var logicWorld = worldRenderer?.World;

 				// ReplayTimestep = 0 means the replay is paused: we need to keep logicInterval as UI.Timestep to avoid breakage
-				if (logicWorld != null && (!logicWorld.IsReplay || logicWorld.ReplayTimestep != 0))
+				if (logicWorld != null && !(logicWorld.IsReplay && logicWorld.ReplayTimestep == 0))
 					logicInterval = logicWorld == OrderManager.World ? OrderManager.SuggestedTimestep : logicWorld.Timestep;

 				// Ideal time between screen updates
@@ -928,15 +921,15 @@ namespace OpenRA
 		{
 			var endpoints = new List<IPEndPoint>
 			{
-				new(IPAddress.IPv6Any, settings.ListenPort),
-				new(IPAddress.Any, settings.ListenPort)
+				new IPEndPoint(IPAddress.IPv6Any, settings.ListenPort),
+				new IPEndPoint(IPAddress.Any, settings.ListenPort)
 			};
 			server = new Server.Server(endpoints, settings, ModData, ServerType.Multiplayer);

 			return server.GetEndpointForLocalConnection();
 		}

-		public static ConnectionTarget CreateLocalServer(string map, bool isSkirmish = false)
+		public static ConnectionTarget CreateLocalServer(string map)
 		{
 			var settings = new ServerSettings()
 			{
@@ -950,9 +943,9 @@ namespace OpenRA
 			// This would break the Restart button, which relies on the PlayerIndex always being the same for local servers
 			var endpoints = new List<IPEndPoint>
 			{
-				new(IPAddress.Loopback, 0)
+				new IPEndPoint(IPAddress.Loopback, 0)
 			};
-			server = new Server.Server(endpoints, settings, ModData, isSkirmish ? ServerType.Skirmish : ServerType.Local);
+			server = new Server.Server(endpoints, settings, ModData, ServerType.Local);

 			return server.GetEndpointForLocalConnection();
 		}
--- a/OpenRA.Game/GameInformation.cs
+++ b/OpenRA.Game/GameInformation.cs
@@ -36,7 +36,7 @@ namespace OpenRA
 		public TimeSpan Duration => EndTimeUtc > StartTimeUtc ? EndTimeUtc - StartTimeUtc : TimeSpan.Zero;

 		public IList<Player> Players { get; }
-		public HashSet<int> DisabledSpawnPoints = new();
+		public HashSet<int> DisabledSpawnPoints = new HashSet<int>();
 		public MapPreview MapPreview => Game.ModData.MapCache[MapUid];
 		public IEnumerable<Player> HumanPlayers { get { return Players.Where(p => p.IsHuman); } }
 		public bool IsSinglePlayer => HumanPlayers.Count() == 1;
@@ -49,13 +49,13 @@ namespace OpenRA
 			playersByRuntime = new Dictionary<OpenRA.Player, Player>();
 		}

-		public static GameInformation Deserialize(string data, string path)
+		public static GameInformation Deserialize(string data)
 		{
 			try
 			{
 				var info = new GameInformation();

-				var nodes = MiniYaml.FromString(data, path);
+				var nodes = MiniYaml.FromString(data);
 				foreach (var node in nodes)
 				{
 					var keyParts = node.Key.Split('@');
@@ -85,7 +85,7 @@ namespace OpenRA
 		{
 			var nodes = new List<MiniYamlNode>
 			{
-				new("Root", FieldSaver.Save(this))
+				new MiniYamlNode("Root", FieldSaver.Save(this))
 			};

 			for (var i = 0; i < Players.Count; i++)
--- a/OpenRA.Game/GameRules/ActorInfo.cs
+++ b/OpenRA.Game/GameRules/ActorInfo.cs
@@ -22,7 +22,7 @@ namespace OpenRA
 	/// </summary>
 	public class ActorInfo
 	{
-		public const char AbstractActorPrefix = '^';
+		public const string AbstractActorPrefix = "^";
 		public const char TraitInstanceSeparator = '@';

 		/// <summary>
@@ -32,7 +32,7 @@ namespace OpenRA
 		/// You can remove inherited traits by adding a - in front of them as in -TraitName: to inherit everything, but this trait.
 		/// </summary>
 		public readonly string Name;
-		readonly TypeDictionary traits = new();
+		readonly TypeDictionary traits = new TypeDictionary();
 		List<TraitInfo> constructOrderCache = null;

 		public ActorInfo(ObjectCreator creator, string name, MiniYaml node)
@@ -115,54 +115,45 @@ namespace OpenRA
 			}).ToList();

 			var resolved = source.Where(s => s.Dependencies.Count == 0 && s.OptionalDependencies.Count == 0).ToList();
-			var unresolved = source.ToHashSet();
-			unresolved.ExceptWith(resolved);
+			var unresolved = source.Except(resolved);

-			static bool AreResolvable(Type a, Type b) => a.IsAssignableFrom(b);
+			var testResolve = new Func<Type, Type, bool>((a, b) => a == b || a.IsAssignableFrom(b));

 			// This query detects which unresolved traits can be immediately resolved as all their direct dependencies are met.
 			var more = unresolved.Where(u =>
 				u.Dependencies.All(d => // To be resolvable, all dependencies must be satisfied according to the following conditions:
-					resolved.Exists(r => AreResolvable(d, r.Type)) && // There must exist a resolved trait that meets the dependency.
-					!unresolved.Any(u1 => AreResolvable(d, u1.Type))) && // All matching traits that meet this dependency must be resolved first.
+					resolved.Exists(r => testResolve(d, r.Type)) && // There must exist a resolved trait that meets the dependency.
+					!unresolved.Any(u1 => testResolve(d, u1.Type))) && // All matching traits that meet this dependency must be resolved first.
 				u.OptionalDependencies.All(d => // To be resolvable, all optional dependencies must be satisfied according to the following condition:
-					!unresolved.Any(u1 => AreResolvable(d, u1.Type)))); // All matching traits that meet this optional dependencies must be resolved first.
+					!unresolved.Any(u1 => testResolve(d, u1.Type)))); // All matching traits that meet this optional dependencies must be resolved first.

 			// Continue resolving traits as long as possible.
 			// Each time we resolve some traits, this means dependencies for other traits may then be possible to satisfy in the next pass.
-#pragma warning disable CA1851 // Possible multiple enumerations of 'IEnumerable' collection
-			var readyToResolve = more.ToList();
-			while (readyToResolve.Count != 0)
-			{
-				resolved.AddRange(readyToResolve);
-				unresolved.ExceptWith(readyToResolve);
-				readyToResolve.Clear();
-				readyToResolve.AddRange(more);
-			}
-#pragma warning restore CA1851
+			while (more.Any())
+				resolved.AddRange(more);

-			if (unresolved.Count != 0)
+			if (unresolved.Any())
 			{
-				var exceptionString = "ActorInfo(\"" + Name + "\") failed to initialize because of the following:\n";
-				var missing = unresolved.SelectMany(u => u.Dependencies.Where(d => !source.Any(s => AreResolvable(d, s.Type)))).Distinct();
+				var exceptionString = "ActorInfo(\"" + Name + "\") failed to initialize because of the following:\r\n";
+				var missing = unresolved.SelectMany(u => u.Dependencies.Where(d => !source.Any(s => testResolve(d, s.Type)))).Distinct();

-				exceptionString += "Missing:\n";
+				exceptionString += "Missing:\r\n";
 				foreach (var m in missing)
-					exceptionString += m + " \n";
+					exceptionString += m + " \r\n";

-				exceptionString += "Unresolved:\n";
+				exceptionString += "Unresolved:\r\n";
 				foreach (var u in unresolved)
 				{
 					var deps = u.Dependencies.Where(d => !resolved.Exists(r => r.Type == d));
 					var optDeps = u.OptionalDependencies.Where(d => !resolved.Exists(r => r.Type == d));
 					var allDeps = string.Join(", ", deps.Select(o => o.ToString()).Concat(optDeps.Select(o => $"[{o}]")));
-					exceptionString += $"{u.Type}: {{ {allDeps} }}\n";
+					exceptionString += $"{u.Type}: {{ {allDeps} }}\r\n";
 				}

 				throw new YamlException(exceptionString);
 			}

-			constructOrderCache = resolved.ConvertAll(r => r.Trait);
+			constructOrderCache = resolved.Select(r => r.Trait).ToList();
 			return constructOrderCache;
 		}

@@ -187,7 +178,7 @@ namespace OpenRA
 		public bool HasTraitInfo<T>() where T : ITraitInfoInterface { return traits.Contains<T>(); }
 		public T TraitInfo<T>() where T : ITraitInfoInterface { return traits.Get<T>(); }
 		public T TraitInfoOrDefault<T>() where T : ITraitInfoInterface { return traits.GetOrDefault<T>(); }
-		public IReadOnlyCollection<T> TraitInfos<T>() where T : ITraitInfoInterface { return traits.WithInterface<T>(); }
+		public IEnumerable<T> TraitInfos<T>() where T : ITraitInfoInterface { return traits.WithInterface<T>(); }

 		public BitSet<TargetableType> GetAllTargetTypes()
 		{
--- a/OpenRA.Game/GameRules/MusicInfo.cs
+++ b/OpenRA.Game/GameRules/MusicInfo.cs
@@ -28,14 +28,14 @@ namespace OpenRA.GameRules
 			Title = value.Value;

 			var nd = value.ToDictionary();
-			if (nd.TryGetValue("Hidden", out var yaml))
-				bool.TryParse(yaml.Value, out Hidden);
+			if (nd.ContainsKey("Hidden"))
+				bool.TryParse(nd["Hidden"].Value, out Hidden);

-			if (nd.TryGetValue("VolumeModifier", out yaml))
-				VolumeModifier = FieldLoader.GetValue<float>("VolumeModifier", yaml.Value);
+			if (nd.ContainsKey("VolumeModifier"))
+				VolumeModifier = FieldLoader.GetValue<float>("VolumeModifier", nd["VolumeModifier"].Value);

-			var ext = nd.TryGetValue("Extension", out yaml) ? yaml.Value : "aud";
-			Filename = (nd.TryGetValue("Filename", out yaml) ? yaml.Value : key) + "." + ext;
+			var ext = nd.ContainsKey("Extension") ? nd["Extension"].Value : "aud";
+			Filename = (nd.ContainsKey("Filename") ? nd["Filename"].Value : key) + "." + ext;
 		}

 		public void Load(IReadOnlyFileSystem fileSystem)
--- a/OpenRA.Game/GameRules/Ruleset.cs
+++ b/OpenRA.Game/GameRules/Ruleset.cs
@@ -15,6 +15,7 @@ using System.Linq;
 using System.Threading.Tasks;
 using OpenRA.FileSystem;
 using OpenRA.GameRules;
+using OpenRA.Graphics;
 using OpenRA.Traits;

 namespace OpenRA
@@ -27,6 +28,7 @@ namespace OpenRA
 		public readonly IReadOnlyDictionary<string, SoundInfo> Notifications;
 		public readonly IReadOnlyDictionary<string, MusicInfo> Music;
 		public readonly ITerrainInfo TerrainInfo;
+		public readonly SequenceProvider Sequences;
 		public readonly IReadOnlyDictionary<string, MiniYamlNode> ModelSequences;

 		public Ruleset(
@@ -36,6 +38,7 @@ namespace OpenRA
 			IReadOnlyDictionary<string, SoundInfo> notifications,
 			IReadOnlyDictionary<string, MusicInfo> music,
 			ITerrainInfo terrainInfo,
+			SequenceProvider sequences,
 			IReadOnlyDictionary<string, MiniYamlNode> modelSequences)
 		{
 			Actors = new ActorInfoDictionary(actors);
@@ -44,6 +47,7 @@ namespace OpenRA
 			Notifications = notifications;
 			Music = music;
 			TerrainInfo = terrainInfo;
+			Sequences = sequences;
 			ModelSequences = modelSequences;

 			foreach (var a in Actors.Values)
@@ -120,11 +124,11 @@ namespace OpenRA
 			var fs = modData.DefaultFileSystem;

 			Ruleset ruleset = null;
-			void LoadRuleset()
+			Action f = () =>
 			{
 				var actors = MergeOrDefault("Manifest,Rules", fs, m.Rules, null, null,
 					k => new ActorInfo(modData.ObjectCreator, k.Key.ToLowerInvariant(), k.Value),
-					filterNode: n => n.Key.StartsWith(ActorInfo.AbstractActorPrefix));
+					filterNode: n => n.Key.StartsWith(ActorInfo.AbstractActorPrefix, StringComparison.Ordinal));

 				var weapons = MergeOrDefault("Manifest,Weapons", fs, m.Weapons, null, null,
 					k => new WeaponInfo(k.Value));
@@ -141,15 +145,15 @@ namespace OpenRA
 				var modelSequences = MergeOrDefault("Manifest,ModelSequences", fs, m.ModelSequences, null, null,
 					k => k);

-				// The default ruleset does not include a preferred tileset
-				ruleset = new Ruleset(actors, weapons, voices, notifications, music, null, modelSequences);
-			}
+				// The default ruleset does not include a preferred tileset or sequence set
+				ruleset = new Ruleset(actors, weapons, voices, notifications, music, null, null, modelSequences);
+			};

 			if (modData.IsOnMainThread)
 			{
 				modData.HandleLoadingProgress();

-				var loader = new Task(LoadRuleset);
+				var loader = new Task(f);
 				loader.Start();

 				// Animate the loadscreen while we wait
@@ -157,7 +161,7 @@ namespace OpenRA
 					modData.HandleLoadingProgress();
 			}
 			else
-				LoadRuleset();
+				f();

 			return ruleset;
 		}
@@ -166,23 +170,24 @@ namespace OpenRA
 		{
 			var dr = modData.DefaultRules;
 			var terrainInfo = modData.DefaultTerrainInfo[tileSet];
+			var sequences = modData.DefaultSequences[tileSet];

-			return new Ruleset(dr.Actors, dr.Weapons, dr.Voices, dr.Notifications, dr.Music, terrainInfo, dr.ModelSequences);
+			return new Ruleset(dr.Actors, dr.Weapons, dr.Voices, dr.Notifications, dr.Music, terrainInfo, sequences, dr.ModelSequences);
 		}

 		public static Ruleset Load(ModData modData, IReadOnlyFileSystem fileSystem, string tileSet,
 			MiniYaml mapRules, MiniYaml mapWeapons, MiniYaml mapVoices, MiniYaml mapNotifications,
-			MiniYaml mapMusic, MiniYaml mapModelSequences)
+			MiniYaml mapMusic, MiniYaml mapSequences, MiniYaml mapModelSequences)
 		{
 			var m = modData.Manifest;
 			var dr = modData.DefaultRules;

 			Ruleset ruleset = null;
-			void LoadRuleset()
+			Action f = () =>
 			{
 				var actors = MergeOrDefault("Rules", fileSystem, m.Rules, mapRules, dr.Actors,
 					k => new ActorInfo(modData.ObjectCreator, k.Key.ToLowerInvariant(), k.Value),
-					filterNode: n => n.Key.StartsWith(ActorInfo.AbstractActorPrefix));
+					filterNode: n => n.Key.StartsWith(ActorInfo.AbstractActorPrefix, StringComparison.Ordinal));

 				var weapons = MergeOrDefault("Weapons", fileSystem, m.Weapons, mapWeapons, dr.Weapons,
 					k => new WeaponInfo(k.Value));
@@ -199,19 +204,23 @@ namespace OpenRA
 				// TODO: Add support for merging custom terrain modifications
 				var terrainInfo = modData.DefaultTerrainInfo[tileSet];

+				// TODO: Top-level dictionary should be moved into the Ruleset instead of in its own object
+				var sequences = mapSequences == null ? modData.DefaultSequences[tileSet] :
+					new SequenceProvider(fileSystem, modData, tileSet, mapSequences);
+
 				var modelSequences = dr.ModelSequences;
 				if (mapModelSequences != null)
 					modelSequences = MergeOrDefault("ModelSequences", fileSystem, m.ModelSequences, mapModelSequences, dr.ModelSequences,
 						k => k);

-				ruleset = new Ruleset(actors, weapons, voices, notifications, music, terrainInfo, modelSequences);
-			}
+				ruleset = new Ruleset(actors, weapons, voices, notifications, music, terrainInfo, sequences, modelSequences);
+			};

 			if (modData.IsOnMainThread)
 			{
 				modData.HandleLoadingProgress();

-				var loader = new Task(LoadRuleset);
+				var loader = new Task(f);
 				loader.Start();

 				// Animate the loadscreen while we wait
@@ -219,17 +228,17 @@ namespace OpenRA
 					modData.HandleLoadingProgress();
 			}
 			else
-				LoadRuleset();
+				f();

 			return ruleset;
 		}

 		static bool AnyCustomYaml(MiniYaml yaml)
 		{
-			return yaml != null && (yaml.Value != null || yaml.Nodes.Length > 0);
+			return yaml != null && (yaml.Value != null || yaml.Nodes.Count > 0);
 		}

-		static bool AnyFlaggedTraits(ModData modData, IEnumerable<MiniYamlNode> actors)
+		static bool AnyFlaggedTraits(ModData modData, List<MiniYamlNode> actors)
 		{
 			foreach (var actorNode in actors)
 			{
@@ -244,7 +253,7 @@ namespace OpenRA
 					}
 					catch (Exception ex)
 					{
-						Log.Write("debug", "Error in AnyFlaggedTraits\n" + ex.ToString());
+						Log.Write("debug", "Error in AnyFlaggedTraits\r\n" + ex.ToString());
 					}
 				}
 			}
@@ -260,18 +269,18 @@ namespace OpenRA
 				return true;

 			// Any trait overrides that aren't explicitly whitelisted are flagged
-			if (mapRules == null)
-				return false;
-
-			if (AnyFlaggedTraits(modData, mapRules.Nodes))
-				return true;
-
-			if (mapRules.Value != null)
+			if (mapRules != null)
 			{
-				var mapFiles = FieldLoader.GetValue<string[]>("value", mapRules.Value);
-				foreach (var f in mapFiles)
-					if (AnyFlaggedTraits(modData, MiniYaml.FromStream(fileSystem.Open(f), f)))
-						return true;
+				if (AnyFlaggedTraits(modData, mapRules.Nodes))
+					return true;
+
+				if (mapRules.Value != null)
+				{
+					var mapFiles = FieldLoader.GetValue<string[]>("value", mapRules.Value);
+					foreach (var f in mapFiles)
+						if (AnyFlaggedTraits(modData, MiniYaml.FromStream(fileSystem.Open(f), f)))
+							return true;
+				}
 			}

 			return false;
--- a/OpenRA.Game/GameRules/SoundInfo.cs
+++ b/OpenRA.Game/GameRules/SoundInfo.cs
@@ -17,14 +17,14 @@ namespace OpenRA.GameRules
 {
 	public class SoundInfo
 	{
-		public readonly Dictionary<string, string[]> Variants = new();
-		public readonly Dictionary<string, string[]> Prefixes = new();
-		public readonly Dictionary<string, string[]> Voices = new();
-		public readonly Dictionary<string, string[]> Notifications = new();
+		public readonly Dictionary<string, string[]> Variants = new Dictionary<string, string[]>();
+		public readonly Dictionary<string, string[]> Prefixes = new Dictionary<string, string[]>();
+		public readonly Dictionary<string, string[]> Voices = new Dictionary<string, string[]>();
+		public readonly Dictionary<string, string[]> Notifications = new Dictionary<string, string[]>();
 		public readonly string DefaultVariant = ".aud";
 		public readonly string DefaultPrefix = "";
-		public readonly HashSet<string> DisableVariants = new();
-		public readonly HashSet<string> DisablePrefixes = new();
+		public readonly HashSet<string> DisableVariants = new HashSet<string>();
+		public readonly HashSet<string> DisablePrefixes = new HashSet<string>();

 		public readonly Lazy<Dictionary<string, SoundPool>> VoicePools;
 		public readonly Lazy<Dictionary<string, SoundPool>> NotificationsPools;
@@ -40,16 +40,16 @@ namespace OpenRA.GameRules
 		static Dictionary<string, SoundPool> ParseSoundPool(MiniYaml y, string key)
 		{
 			var ret = new Dictionary<string, SoundPool>();
-			var classifiction = y.NodeWithKey(key);
+			var classifiction = y.Nodes.First(x => x.Key == key);
 			foreach (var t in classifiction.Value.Nodes)
 			{
 				var volumeModifier = 1f;
-				var volumeModifierNode = t.Value.NodeWithKeyOrDefault(nameof(SoundPool.VolumeModifier));
+				var volumeModifierNode = t.Value.Nodes.FirstOrDefault(x => x.Key == nameof(SoundPool.VolumeModifier));
 				if (volumeModifierNode != null)
 					volumeModifier = FieldLoader.GetValue<float>(volumeModifierNode.Key, volumeModifierNode.Value.Value);

 				var interruptType = SoundPool.DefaultInterruptType;
-				var interruptTypeNode = t.Value.NodeWithKeyOrDefault(nameof(SoundPool.InterruptType));
+				var interruptTypeNode = t.Value.Nodes.FirstOrDefault(x => x.Key == nameof(SoundPool.InterruptType));
 				if (interruptTypeNode != null)
 					interruptType = FieldLoader.GetValue<SoundPool.InterruptType>(interruptTypeNode.Key, interruptTypeNode.Value.Value);

@@ -69,7 +69,7 @@ namespace OpenRA.GameRules
 		public readonly float VolumeModifier;
 		public readonly InterruptType Type;
 		readonly string[] clips;
-		readonly List<string> liveclips = new();
+		readonly List<string> liveclips = new List<string>();

 		public SoundPool(float volumeModifier, InterruptType interruptType, params string[] clips)
 		{
--- a/OpenRA.Game/GameRules/WeaponInfo.cs
+++ b/OpenRA.Game/GameRules/WeaponInfo.cs
@@ -103,16 +103,16 @@ namespace OpenRA.GameRules
 		public readonly bool CanTargetSelf = false;

 		[Desc("What types of targets are affected.")]
-		public readonly BitSet<TargetableType> ValidTargets = new("Ground", "Water");
+		public readonly BitSet<TargetableType> ValidTargets = new BitSet<TargetableType>("Ground", "Water");

 		[Desc("What types of targets are unaffected.", "Overrules ValidTargets.")]
 		public readonly BitSet<TargetableType> InvalidTargets;

-		static readonly BitSet<TargetableType> TargetTypeAir = new("Air");
+		static readonly BitSet<TargetableType> TargetTypeAir = new BitSet<TargetableType>("Air");

 		[Desc("If weapon is not directly targeting an actor and targeted position is above this altitude,",
 			"the weapon will ignore terrain target types and only check TargetTypeAir for validity.")]
-		public readonly WDist AirThreshold = new(128);
+		public readonly WDist AirThreshold = new WDist(128);

 		[Desc("Delay in ticks between firing shots from the same ammo magazine. If one entry, it will be used for all bursts.",
 			"If multiple entries, their number needs to match Burst - 1.")]
@@ -128,10 +128,10 @@ namespace OpenRA.GameRules
 		public readonly IProjectileInfo Projectile;

 		[FieldLoader.LoadUsing(nameof(LoadWarheads))]
-		public readonly List<IWarhead> Warheads = new();
+		public readonly List<IWarhead> Warheads = new List<IWarhead>();

 		/// <summary>
-		/// This constructor is used solely for documentation generation.
+		/// This constructor is used solely for documentation generation!
 		/// </summary>
 		public WeaponInfo() { }

@@ -139,14 +139,13 @@ namespace OpenRA.GameRules
 		{
 			// Resolve any weapon-level yaml inheritance or removals
 			// HACK: The "Defaults" sequence syntax prevents us from doing this generally during yaml parsing
-			content = content.WithNodes(MiniYaml.Merge(new IReadOnlyCollection<MiniYamlNode>[] { content.Nodes }));
+			content.Nodes = MiniYaml.Merge(new[] { content.Nodes });
 			FieldLoader.Load(this, content);
 		}

 		static object LoadProjectile(MiniYaml yaml)
 		{
-			var proj = yaml.NodeWithKeyOrDefault("Projectile")?.Value;
-			if (proj == null)
+			if (!yaml.ToDictionary().TryGetValue("Projectile", out var proj))
 				return null;

 			var ret = Game.CreateObject<IProjectileInfo>(proj.Value + "Info");
@@ -160,7 +159,7 @@ namespace OpenRA.GameRules
 		static object LoadWarheads(MiniYaml yaml)
 		{
 			var retList = new List<IWarhead>();
-			foreach (var node in yaml.Nodes.Where(n => n.Key.StartsWith("Warhead", StringComparison.Ordinal)))
+			foreach (var node in yaml.Nodes.Where(n => n.Key.StartsWith("Warhead")))
 			{
 				var ret = Game.CreateObject<IWarhead>(node.Value.Value + "Warhead");
 				if (ret == null)
--- a/OpenRA.Game/GameSpeed.cs
+++ b/OpenRA.Game/GameSpeed.cs
@@ -10,6 +10,7 @@
 #endregion

 using System.Collections.Generic;
+using System.Linq;

 namespace OpenRA
 {
@@ -37,7 +38,7 @@ namespace OpenRA
 		static object LoadSpeeds(MiniYaml y)
 		{
 			var ret = new Dictionary<string, GameSpeed>();
-			var speedsNode = y.NodeWithKeyOrDefault("Speeds");
+			var speedsNode = y.Nodes.FirstOrDefault(n => n.Key == "Speeds");
 			if (speedsNode == null)
 				throw new YamlException("Error parsing GameSpeeds: Missing Speeds node!");

--- a/OpenRA.Game/Graphics/Animation.cs
+++ b/OpenRA.Game/Graphics/Animation.cs
@@ -22,7 +22,7 @@ namespace OpenRA.Graphics
 		public string Name { get; private set; }
 		public bool IsDecoration { get; set; }

-		readonly SequenceSet sequences;
+		readonly SequenceProvider sequenceProvider;
 		readonly Func<WAngle> facingFunc;
 		readonly Func<bool> paused;

@@ -30,7 +30,7 @@ namespace OpenRA.Graphics
 		bool backwards;
 		bool tickAlways;
 		int timeUntilNextFrame;
-		Action tickFunc;
+		Action tickFunc = () => { };

 		public Animation(World world, string name)
 			: this(world, name, () => WAngle.Zero) { }
@@ -43,7 +43,7 @@ namespace OpenRA.Graphics

 		public Animation(World world, string name, Func<WAngle> facingFunc, Func<bool> paused)
 		{
-			sequences = world.Map.Sequences;
+			sequenceProvider = world.Map.Rules.Sequences;
 			Name = name.ToLowerInvariant();
 			this.facingFunc = facingFunc;
 			this.paused = paused;
@@ -61,9 +61,9 @@ namespace OpenRA.Graphics
 			var imageRenderable = new SpriteRenderable(image, pos, offset, CurrentSequence.ZOffset + zOffset, palette, CurrentSequence.Scale, alpha, float3.Ones, tintModifiers, IsDecoration,
 				rotation);

-			var shadow = CurrentSequence.GetShadow(CurrentFrame, facingFunc());
-			if (shadow != null)
+			if (CurrentSequence.ShadowStart >= 0)
 			{
+				var shadow = CurrentSequence.GetShadow(CurrentFrame, facingFunc());
 				var shadowRenderable = new SpriteRenderable(shadow, pos, offset, CurrentSequence.ShadowZOffset + zOffset, palette, CurrentSequence.Scale, 1f, float3.Ones, tintModifiers,
 					true, rotation);
 				return new IRenderable[] { shadowRenderable, imageRenderable };
@@ -80,9 +80,9 @@ namespace OpenRA.Graphics
 			var alpha = CurrentSequence.GetAlpha(CurrentFrame);
 			var imageRenderable = new UISpriteRenderable(Image, WPos.Zero + offset, imagePos, CurrentSequence.ZOffset + zOffset, palette, scale, alpha, rotation);

-			var shadow = CurrentSequence.GetShadow(CurrentFrame, facingFunc());
-			if (shadow != null)
+			if (CurrentSequence.ShadowStart >= 0)
 			{
+				var shadow = CurrentSequence.GetShadow(CurrentFrame, facingFunc());
 				var shadowPos = pos - new int2((int)(scale * shadow.Size.X / 2), (int)(scale * shadow.Size.Y / 2));
 				var shadowRenderable = new UISpriteRenderable(shadow, WPos.Zero + offset, shadowPos, CurrentSequence.ShadowZOffset + zOffset, palette, scale, 1f, rotation);
 				return new IRenderable[] { shadowRenderable, imageRenderable };
@@ -164,7 +164,7 @@ namespace OpenRA.Graphics
 				if (frame >= CurrentSequence.Length)
 				{
 					frame = CurrentSequence.Length - 1;
-					tickFunc = null;
+					tickFunc = () => { };
 					after?.Invoke();
 				}
 			};
@@ -212,13 +212,13 @@ namespace OpenRA.Graphics
 		public void Tick(int t)
 		{
 			if (tickAlways)
-				tickFunc?.Invoke();
+				tickFunc();
 			else
 			{
 				timeUntilNextFrame -= t;
 				while (timeUntilNextFrame <= 0)
 				{
-					tickFunc?.Invoke();
+					tickFunc();
 					timeUntilNextFrame += CurrentSequenceTickOrDefault();
 				}
 			}
@@ -236,11 +236,11 @@ namespace OpenRA.Graphics
 			}
 		}

-		public bool HasSequence(string seq) { return sequences.HasSequence(Name, seq); }
+		public bool HasSequence(string seq) { return sequenceProvider.HasSequence(Name, seq); }

 		public ISpriteSequence GetSequence(string sequenceName)
 		{
-			return sequences.GetSequence(Name, sequenceName);
+			return sequenceProvider.GetSequence(Name, sequenceName);
 		}

 		public string GetRandomExistingSequence(string[] sequences, MersenneTwister random)
--- a/OpenRA.Game/Graphics/ChromeProvider.cs
+++ b/OpenRA.Game/Graphics/ChromeProvider.cs
@@ -49,7 +49,7 @@ namespace OpenRA.Graphics

 			public readonly int[] PanelRegion = null;
 			public readonly PanelSides PanelSides = PanelSides.All;
-			public readonly Dictionary<string, Rectangle> Regions = new();
+			public readonly Dictionary<string, Rectangle> Regions = new Dictionary<string, Rectangle>();
 		}

 		public static IReadOnlyDictionary<string, Collection> Collections => collections;
@@ -77,12 +77,11 @@ namespace OpenRA.Graphics
 			cachedPanelSprites = new Dictionary<string, Sprite[]>();
 			cachedCollectionSheets = new Dictionary<Collection, (Sheet, int)>();

-			var stringPool = new HashSet<string>(); // Reuse common strings in YAML
 			var chrome = MiniYaml.Merge(modData.Manifest.Chrome
-				.Select(s => MiniYaml.FromStream(fileSystem.Open(s), s, stringPool: stringPool)));
+				.Select(s => MiniYaml.FromStream(fileSystem.Open(s), s)));

 			foreach (var c in chrome)
-				if (!c.Key.StartsWith('^'))
+				if (!c.Key.StartsWith("^", StringComparison.Ordinal))
 					LoadCollection(c.Key, c.Value);
 		}

@@ -101,7 +100,9 @@ namespace OpenRA.Graphics

 		static void LoadCollection(string name, MiniYaml yaml)
 		{
-			Game.ModData.LoadScreen?.Display();
+			if (Game.ModData.LoadScreen != null)
+				Game.ModData.LoadScreen.Display();
+
 			collections.Add(name, FieldLoader.Load<Collection>(yaml));
 		}

@@ -235,7 +236,7 @@ namespace OpenRA.Graphics
 			{
 				// PERF: We don't need to search for images if there are no definitions.
 				// PERF: It's more efficient to send an empty array rather than an array of 9 nulls.
-				if (collection.Regions.Count == 0)
+				if (!collection.Regions.Any())
 					return Array.Empty<Sprite>();

 				// Support manual definitions for unusual dialog layouts
@@ -264,13 +265,13 @@ namespace OpenRA.Graphics

 			if (!collections.TryGetValue(collectionName, out var collection))
 			{
-				Log.Write("debug", $"Could not find collection '{collectionName}'");
+				Log.Write("debug", "Could not find collection '{0}'", collectionName);
 				return new Size(0, 0);
 			}

 			if (collection.PanelRegion == null || collection.PanelRegion.Length != 8)
 			{
-				Log.Write("debug", $"Collection '{collectionName}' does not define a valid PanelRegion");
+				Log.Write("debug", "Collection '{0}' does not define a valid PanelRegion", collectionName);
 				return new Size(0, 0);
 			}

--- a/OpenRA.Game/Graphics/CursorManager.cs
+++ b/OpenRA.Game/Graphics/CursorManager.cs
@@ -17,7 +17,7 @@ namespace OpenRA.Graphics
 {
 	public sealed class CursorManager
 	{
-		sealed class Cursor
+		class Cursor
 		{
 			public string Name;
 			public int2 PaddedSize;
@@ -28,7 +28,7 @@ namespace OpenRA.Graphics
 			public IHardwareCursor[] Cursors;
 		}

-		readonly Dictionary<string, Cursor> cursors = new();
+		readonly Dictionary<string, Cursor> cursors = new Dictionary<string, Cursor>();
 		readonly SheetBuilder sheetBuilder;
 		readonly GraphicSettings graphicSettings;

@@ -111,7 +111,8 @@ namespace OpenRA.Graphics
 				var template = kv.Value;
 				for (var i = 0; i < template.Sprites.Length; i++)
 				{
-					template.Cursors[i]?.Dispose();
+					if (template.Cursors[i] != null)
+						template.Cursors[i].Dispose();

 					// Calculate the padding to position the frame within sequenceBounds
 					var paddingTL = -(template.Bounds.Location - template.Sprites[i].Offset.XY.ToInt2());
--- a/OpenRA.Game/Graphics/CursorProvider.cs
+++ b/OpenRA.Game/Graphics/CursorProvider.cs
@@ -24,11 +24,10 @@ namespace OpenRA.Graphics
 		public CursorProvider(ModData modData)
 		{
 			var fileSystem = modData.DefaultFileSystem;
-			var stringPool = new HashSet<string>(); // Reuse common strings in YAML
 			var sequenceYaml = MiniYaml.Merge(modData.Manifest.Cursors.Select(
-				s => MiniYaml.FromStream(fileSystem.Open(s), s, stringPool: stringPool)));
+				s => MiniYaml.FromStream(fileSystem.Open(s), s)));

-			var cursorsYaml = new MiniYaml(null, sequenceYaml).NodeWithKey("Cursors").Value;
+			var nodesDict = new MiniYaml(null, sequenceYaml).ToDictionary();

 			// Overwrite previous definitions if there are duplicates
 			var pals = new Dictionary<string, IProvidesCursorPaletteInfo>();
@@ -36,14 +35,14 @@ namespace OpenRA.Graphics
 				if (p.Palette != null)
 					pals[p.Palette] = p;

-			Palettes = cursorsYaml.Nodes.Select(n => n.Value.Value)
+			Palettes = nodesDict["Cursors"].Nodes.Select(n => n.Value.Value)
 				.Where(p => p != null)
 				.Distinct()
 				.ToDictionary(p => p, p => pals[p].ReadPalette(modData.DefaultFileSystem));

 			var frameCache = new FrameCache(fileSystem, modData.SpriteLoaders);
 			var cursors = new Dictionary<string, CursorSequence>();
-			foreach (var s in cursorsYaml.Nodes)
+			foreach (var s in nodesDict["Cursors"].Nodes)
 				foreach (var sequence in s.Value.Nodes)
 					cursors.Add(sequence.Key, new CursorSequence(frameCache, sequence.Key, s.Key, s.Value.Value, sequence.Value));

--- a/OpenRA.Game/Graphics/CursorSequence.cs
+++ b/OpenRA.Game/Graphics/CursorSequence.cs
@@ -27,20 +27,19 @@ namespace OpenRA.Graphics
 		{
 			var d = info.ToDictionary();

-			Start = Exts.ParseInt32Invariant(d["Start"].Value);
+			Start = Exts.ParseIntegerInvariant(d["Start"].Value);
 			Palette = palette;
 			Name = name;

 			var cursorSprites = cache[cursorSrc];
 			Frames = cursorSprites.Skip(Start).ToArray();

-			if ((d.TryGetValue("Length", out var yaml) && yaml.Value == "*") ||
-				(d.TryGetValue("End", out yaml) && yaml.Value == "*"))
+			if ((d.ContainsKey("Length") && d["Length"].Value == "*") || (d.ContainsKey("End") && d["End"].Value == "*"))
 				Length = Frames.Length;
-			else if (d.TryGetValue("Length", out yaml))
-				Length = Exts.ParseInt32Invariant(yaml.Value);
-			else if (d.TryGetValue("End", out yaml))
-				Length = Exts.ParseInt32Invariant(yaml.Value) - Start;
+			else if (d.ContainsKey("Length"))
+				Length = Exts.ParseIntegerInvariant(d["Length"].Value);
+			else if (d.ContainsKey("End"))
+				Length = Exts.ParseIntegerInvariant(d["End"].Value) - Start;
 			else
 				Length = 1;

@@ -52,15 +51,15 @@ namespace OpenRA.Graphics
 			if (Length > cursorSprites.Length)
 				throw new YamlException($"Cursor {name}: {nameof(Length)} is greater than the length of the sprite sequence.");

-			if (d.TryGetValue("X", out yaml))
+			if (d.ContainsKey("X"))
 			{
-				Exts.TryParseInt32Invariant(yaml.Value, out var x);
+				Exts.TryParseIntegerInvariant(d["X"].Value, out var x);
 				Hotspot = Hotspot.WithX(x);
 			}

-			if (d.TryGetValue("Y", out yaml))
+			if (d.ContainsKey("Y"))
 			{
-				Exts.TryParseInt32Invariant(yaml.Value, out var y);
+				Exts.TryParseIntegerInvariant(d["Y"].Value, out var y);
 				Hotspot = Hotspot.WithY(y);
 			}
 		}
--- a/OpenRA.Game/Graphics/HardwarePalette.cs
+++ b/OpenRA.Game/Graphics/HardwarePalette.cs
@@ -21,9 +21,9 @@ namespace OpenRA.Graphics
 		public ITexture ColorShifts { get; }

 		public int Height { get; private set; }
-		readonly Dictionary<string, ImmutablePalette> palettes = new();
-		readonly Dictionary<string, MutablePalette> mutablePalettes = new();
-		readonly Dictionary<string, int> indices = new();
+		readonly Dictionary<string, ImmutablePalette> palettes = new Dictionary<string, ImmutablePalette>();
+		readonly Dictionary<string, MutablePalette> mutablePalettes = new Dictionary<string, MutablePalette>();
+		readonly Dictionary<string, int> indices = new Dictionary<string, int>();
 		byte[] buffer = Array.Empty<byte>();
 		float[] colorShiftBuffer = Array.Empty<float>();

@@ -70,7 +70,7 @@ namespace OpenRA.Graphics
 			{
 				Height = Exts.NextPowerOf2(index + 1);
 				Array.Resize(ref buffer, Height * Palette.Size * 4);
-				Array.Resize(ref colorShiftBuffer, Height * 8);
+				Array.Resize(ref colorShiftBuffer, Height * 4);
 			}

 			if (allowModifiers)
@@ -79,9 +79,6 @@ namespace OpenRA.Graphics
 				CopyPaletteToBuffer(index, p);
 		}

-		[System.Diagnostics.CodeAnalysis.SuppressMessage(
-			"Performance", "CA1854:Prefer the 'IDictionary.TryGetValue(TKey, out TValue)' method",
-			Justification = "False positive - indexer is a set not a get.")]
 		public void ReplacePalette(string name, IPalette p)
 		{
 			if (mutablePalettes.ContainsKey(name))
@@ -93,20 +90,19 @@ namespace OpenRA.Graphics
 			CopyBufferToTexture();
 		}

-		public void SetColorShift(string name, float hueOffset, float satOffset, float valueMultiplier, float minHue, float maxHue)
+		public void SetColorShift(string name, float hueOffset, float satOffset, float minHue, float maxHue)
 		{
 			var index = GetPaletteIndex(name);
-			colorShiftBuffer[8 * index + 0] = minHue;
-			colorShiftBuffer[8 * index + 1] = maxHue;
-			colorShiftBuffer[8 * index + 4] = hueOffset;
-			colorShiftBuffer[8 * index + 5] = satOffset;
-			colorShiftBuffer[8 * index + 6] = valueMultiplier;
+			colorShiftBuffer[4 * index + 0] = hueOffset;
+			colorShiftBuffer[4 * index + 1] = satOffset;
+			colorShiftBuffer[4 * index + 2] = minHue;
+			colorShiftBuffer[4 * index + 3] = maxHue;
 		}

 		public bool HasColorShift(string name)
 		{
 			var index = GetPaletteIndex(name);
-			return colorShiftBuffer[8 * index] != 0 || colorShiftBuffer[8 * index + 1] != 0;
+			return colorShiftBuffer[4 * index + 2] != 0 || colorShiftBuffer[4 * index + 3] != 0;
 		}

 		public void Initialize()
@@ -129,7 +125,7 @@ namespace OpenRA.Graphics
 		void CopyBufferToTexture()
 		{
 			Texture.SetData(buffer, Palette.Size, Height);
-			ColorShifts.SetFloatData(colorShiftBuffer, 2, Height);
+			ColorShifts.SetFloatData(colorShiftBuffer, 1, Height);
 		}

 		public void ApplyModifiers(IEnumerable<IPaletteModifier> paletteMods)
--- a/OpenRA.Game/Graphics/MarkerTileRenderable.cs
+++ b/OpenRA.Game/Graphics/MarkerTileRenderable.cs
@@ -1,56 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright (c) The OpenRA Developers and Contributors
- * This file is part of OpenRA, which is free software. It is made
- * available to you under the terms of the GNU General Public License
- * as published by the Free Software Foundation, either version 3 of
- * the License, or (at your option) any later version. For more
- * information, see COPYING.
- */
-#endregion
-
-using System.Linq;
-using OpenRA.Primitives;
-
-namespace OpenRA.Graphics
-{
-	public class MarkerTileRenderable : IRenderable, IFinalizedRenderable
-	{
-		readonly CPos pos;
-		readonly Color color;
-
-		public MarkerTileRenderable(CPos pos, Color color)
-		{
-			this.pos = pos;
-			this.color = color;
-		}
-
-		public WPos Pos => WPos.Zero;
-		public int ZOffset => 0;
-		public bool IsDecoration => true;
-
-		public IRenderable WithZOffset(int newOffset) { return this; }
-
-		public IRenderable OffsetBy(in WVec vec)
-		{
-			return new MarkerTileRenderable(pos, color);
-		}
-
-		public IRenderable AsDecoration() { return this; }
-
-		public IFinalizedRenderable PrepareRender(WorldRenderer wr) { return this; }
-		public void Render(WorldRenderer wr)
-		{
-			var map = wr.World.Map;
-			var r = map.Grid.Ramps[map.Ramp[pos]];
-			var wpos = map.CenterOfCell(pos) - new WVec(0, 0, r.CenterHeightOffset);
-
-			var corners = r.Corners.Select(corner => wr.Viewport.WorldToViewPx(wr.Screen3DPosition(wpos + corner))).ToList();
-
-			Game.Renderer.RgbaColorRenderer.FillRect(corners[0], corners[1], corners[2], corners[3], color);
-		}
-
-		public void RenderDebugGeometry(WorldRenderer wr) { }
-		public Rectangle ScreenBounds(WorldRenderer wr) { return Rectangle.Empty; }
-	}
-}
--- a/OpenRA.Game/Graphics/Model.cs
+++ b/OpenRA.Game/Graphics/Model.cs
@@ -10,8 +10,9 @@
 #endregion

 using System;
+using System.Collections.Generic;
+using OpenRA.FileSystem;
 using OpenRA.Primitives;
-using OpenRA.Traits;

 namespace OpenRA.Graphics
 {
@@ -25,18 +26,10 @@ namespace OpenRA.Graphics
 		float[] Bounds(uint frame);
 		ModelRenderData RenderData(uint section);

-		/// <summary>Returns the smallest rectangle that covers all rotations of all frames in a model.</summary>
+		/// <summary>Returns the smallest rectangle that covers all rotations of all frames in a model</summary>
 		Rectangle AggregateBounds { get; }
 	}

-	public interface IModelWidget
-	{
-		public string Palette { get; }
-		public float Scale { get; }
-		public void Setup(Func<bool> isVisible, Func<string> getPalette, Func<string> getPlayerPalette,
-			Func<float> getScale, Func<IModel> getVoxel, Func<WRot> getRotation);
-	}
-
 	public readonly struct ModelRenderData
 	{
 		public readonly int Start;
@@ -51,13 +44,52 @@ namespace OpenRA.Graphics
 		}
 	}

-	public interface IModelCacheInfo : ITraitInfoInterface { }
-
-	public interface IModelCache
+	public interface IModelCache : IDisposable
 	{
 		IModel GetModel(string model);
 		IModel GetModelSequence(string model, string sequence);
 		bool HasModelSequence(string model, string sequence);
-		IVertexBuffer<ModelVertex> VertexBuffer { get; }
+		IVertexBuffer<Vertex> VertexBuffer { get; }
+	}
+
+	public interface IModelSequenceLoader
+	{
+		Action<string> OnMissingModelError { get; set; }
+		IModelCache CacheModels(IReadOnlyFileSystem fileSystem, ModData modData, IReadOnlyDictionary<string, MiniYamlNode> modelDefinitions);
+	}
+
+	public class PlaceholderModelSequenceLoader : IModelSequenceLoader
+	{
+		public Action<string> OnMissingModelError { get; set; }
+
+		class PlaceholderModelCache : IModelCache
+		{
+			public IVertexBuffer<Vertex> VertexBuffer => throw new NotImplementedException();
+
+			public void Dispose() { }
+
+			public IModel GetModel(string model)
+			{
+				throw new NotImplementedException();
+			}
+
+			public IModel GetModelSequence(string model, string sequence)
+			{
+				throw new NotImplementedException();
+			}
+
+			public bool HasModelSequence(string model, string sequence)
+			{
+				throw new NotImplementedException();
+			}
+		}
+
+		[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "IDE0060:Remove unused parameter", Justification = "Load game API")]
+		public PlaceholderModelSequenceLoader(ModData modData) { }
+
+		public IModelCache CacheModels(IReadOnlyFileSystem fileSystem, ModData modData, IReadOnlyDictionary<string, MiniYamlNode> modelDefinitions)
+		{
+			return new PlaceholderModelCache();
+		}
 	}
 }
--- a/OpenRA.Mods.Cnc/Traits/World/ModelRenderer.cs
+++ b/OpenRA.Mods.Cnc/Traits/World/ModelRenderer.cs
@@ -12,11 +12,9 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using OpenRA.Graphics;
 using OpenRA.Primitives;
-using OpenRA.Traits;

-namespace OpenRA.Mods.Cnc.Traits
+namespace OpenRA.Graphics
 {
 	public class ModelRenderProxy
 	{
@@ -34,19 +32,12 @@ namespace OpenRA.Mods.Cnc.Traits
 		}
 	}

-	[TraitLocation(SystemActors.World | SystemActors.EditorWorld)]
-	[Desc("Render voxels")]
-	public class ModelRendererInfo : TraitInfo, Requires<IModelCacheInfo>
-	{
-		public override object Create(ActorInitializer init) { return new ModelRenderer(this, init.Self); }
-	}
-
-	public sealed class ModelRenderer : IDisposable, IRenderer, INotifyActorDisposing
+	public sealed class ModelRenderer : IDisposable
 	{
 		// Static constants
 		static readonly float[] ShadowDiffuse = new float[] { 0, 0, 0 };
 		static readonly float[] ShadowAmbient = new float[] { 1, 1, 1 };
-		static readonly float2 SpritePadding = new(2, 2);
+		static readonly float2 SpritePadding = new float2(2, 2);
 		static readonly float[] ZeroVector = new float[] { 0, 0, 0, 1 };
 		static readonly float[] ZVector = new float[] { 0, 0, 1, 1 };
 		static readonly float[] FlipMtx = Util.ScaleMatrix(1, -1, 1);
@@ -55,32 +46,28 @@ namespace OpenRA.Mods.Cnc.Traits

 		readonly Renderer renderer;
 		readonly IShader shader;
-		public readonly IModelCache ModelCache;

-		readonly Dictionary<Sheet, IFrameBuffer> mappedBuffers = new();
-		readonly Stack<KeyValuePair<Sheet, IFrameBuffer>> unmappedBuffers = new();
-		readonly List<(Sheet Sheet, Action Func)> doRender = new();
-		readonly int sheetSize;
+		readonly Dictionary<Sheet, IFrameBuffer> mappedBuffers = new Dictionary<Sheet, IFrameBuffer>();
+		readonly Stack<KeyValuePair<Sheet, IFrameBuffer>> unmappedBuffers = new Stack<KeyValuePair<Sheet, IFrameBuffer>>();
+		readonly List<(Sheet Sheet, Action Func)> doRender = new List<(Sheet, Action)>();

 		SheetBuilder sheetBuilderForFrame;
 		bool isInFrame;

-		public void SetPalette(HardwarePalette palette)
+		public ModelRenderer(Renderer renderer, IShader shader)
 		{
-			shader.SetTexture("Palette", palette.Texture);
-			shader.SetVec("PaletteRows", palette.Height);
+			this.renderer = renderer;
+			this.shader = shader;
 		}

-		public ModelRenderer(ModelRendererInfo info, Actor self)
+		public void SetPalette(ITexture palette)
 		{
-			renderer = Game.Renderer;
-			shader = renderer.CreateShader(new ModelShaderBindings());
-			renderer.WorldRenderers = renderer.WorldRenderers.Append(this).ToArray();
+			shader.SetTexture("Palette", palette);
+		}

-			ModelCache = self.Trait<IModelCache>();
-
-			sheetSize = Game.Settings.Graphics.SheetSize;
-			var a = 2f / sheetSize;
+		public void SetViewportParams()
+		{
+			var a = 2f / renderer.SheetSize;
 			var view = new[]
 			{
 				a, 0, 0, 0,
@@ -180,7 +167,8 @@ namespace OpenRA.Mods.Cnc.Traits
 			CalculateSpriteGeometry(tl, br, 1, out var spriteSize, out var spriteOffset);
 			CalculateSpriteGeometry(stl, sbr, 2, out var shadowSpriteSize, out var shadowSpriteOffset);

-			sheetBuilderForFrame ??= new SheetBuilder(SheetType.BGRA, AllocateSheet);
+			if (sheetBuilderForFrame == null)
+				sheetBuilderForFrame = new SheetBuilder(SheetType.BGRA, AllocateSheet);

 			var sprite = sheetBuilderForFrame.Allocate(spriteSize, 0, spriteOffset);
 			var shadowSprite = sheetBuilderForFrame.Allocate(shadowSpriteSize, 0, shadowSpriteOffset);
@@ -189,12 +177,12 @@ namespace OpenRA.Mods.Cnc.Traits
 			var spriteCenter = new float2(sb.Left + sb.Width / 2, sb.Top + sb.Height / 2);
 			var shadowCenter = new float2(ssb.Left + ssb.Width / 2, ssb.Top + ssb.Height / 2);

-			var translateMtx = Util.TranslationMatrix(spriteCenter.X - spriteOffset.X, sheetSize - (spriteCenter.Y - spriteOffset.Y), 0);
-			var shadowTranslateMtx = Util.TranslationMatrix(shadowCenter.X - shadowSpriteOffset.X, sheetSize - (shadowCenter.Y - shadowSpriteOffset.Y), 0);
+			var translateMtx = Util.TranslationMatrix(spriteCenter.X - spriteOffset.X, renderer.SheetSize - (spriteCenter.Y - spriteOffset.Y), 0);
+			var shadowTranslateMtx = Util.TranslationMatrix(shadowCenter.X - shadowSpriteOffset.X, renderer.SheetSize - (shadowCenter.Y - shadowSpriteOffset.Y), 0);
 			var correctionTransform = Util.MatrixMultiply(translateMtx, FlipMtx);
 			var shadowCorrectionTransform = Util.MatrixMultiply(shadowTranslateMtx, ShadowScaleFlipMtx);

-			void RenderFunc()
+			doRender.Add((sprite.Sheet, () =>
 			{
 				foreach (var m in models)
 				{
@@ -226,18 +214,16 @@ namespace OpenRA.Mods.Cnc.Traits
 						// Transform light vector from shadow -> world -> limb coords
 						var lightDirection = ExtractRotationVector(Util.MatrixMultiply(it, lightTransform));

-						Render(rd, ModelCache, Util.MatrixMultiply(transform, t), lightDirection,
-							lightAmbientColor, lightDiffuseColor, color.TextureIndex, normals.TextureIndex);
+						Render(rd, wr.World.ModelCache, Util.MatrixMultiply(transform, t), lightDirection,
+							lightAmbientColor, lightDiffuseColor, color.TextureMidIndex, normals.TextureMidIndex);

 						// Disable shadow normals by forcing zero diffuse and identity ambient light
 						if (m.ShowShadow)
-							Render(rd, ModelCache, Util.MatrixMultiply(shadow, t), lightDirection,
-								ShadowAmbient, ShadowDiffuse, shadowPalette.TextureIndex, normals.TextureIndex);
+							Render(rd, wr.World.ModelCache, Util.MatrixMultiply(shadow, t), lightDirection,
+								ShadowAmbient, ShadowDiffuse, shadowPalette.TextureMidIndex, normals.TextureMidIndex);
 					}
 				}
-			}
-
-			doRender.Add((sprite.Sheet, RenderFunc));
+			}));

 			var screenLightVector = Util.MatrixVectorMultiply(invShadowTransform, ZVector);
 			screenLightVector = Util.MatrixVectorMultiply(cameraTransform, screenLightVector);
@@ -252,9 +238,9 @@ namespace OpenRA.Mods.Cnc.Traits

 			// Width and height must be even to avoid rendering glitches
 			if ((width & 1) == 1)
-				width++;
+				width += 1;
 			if ((height & 1) == 1)
-				height++;
+				height += 1;

 			size = new Size(width, height);
 		}
@@ -282,17 +268,17 @@ namespace OpenRA.Mods.Cnc.Traits
 			IModelCache cache,
 			float[] t, float[] lightDirection,
 			float[] ambientLight, float[] diffuseLight,
-			float colorPaletteTextureIndex, float normalsPaletteTextureIndex)
+			float colorPaletteTextureMidIndex, float normalsPaletteTextureMidIndex)
 		{
 			shader.SetTexture("DiffuseTexture", renderData.Sheet.GetTexture());
-			shader.SetVec("Palettes", colorPaletteTextureIndex, normalsPaletteTextureIndex);
+			shader.SetVec("PaletteRows", colorPaletteTextureMidIndex, normalsPaletteTextureMidIndex);
 			shader.SetMatrix("TransformMatrix", t);
 			shader.SetVec("LightDirection", lightDirection, 4);
 			shader.SetVec("AmbientLight", ambientLight, 3);
 			shader.SetVec("DiffuseLight", diffuseLight, 3);

 			shader.PrepareRender();
-			renderer.DrawBatch(cache.VertexBuffer, shader, renderData.Start, renderData.Count, PrimitiveType.TriangleList);
+			renderer.DrawBatch(cache.VertexBuffer, renderData.Start, renderData.Count, PrimitiveType.TriangleList);
 		}

 		public void BeginFrame()
@@ -313,14 +299,14 @@ namespace OpenRA.Mods.Cnc.Traits
 			Game.Renderer.Flush();
 			fbo.Bind();

-			Game.Renderer.EnableDepthBuffer();
+			Game.Renderer.Context.EnableDepthBuffer();
 			return fbo;
 		}

-		static void DisableFrameBuffer(IFrameBuffer fbo)
+		void DisableFrameBuffer(IFrameBuffer fbo)
 		{
 			Game.Renderer.Flush();
-			Game.Renderer.DisableDepthBuffer();
+			Game.Renderer.Context.DisableDepthBuffer();
 			fbo.Unbind();
 		}

@@ -368,7 +354,8 @@ namespace OpenRA.Mods.Cnc.Traits
 				return kv.Key;
 			}

-			var framebuffer = renderer.CreateFrameBuffer(new Size(sheetSize, sheetSize));
+			var size = new Size(renderer.SheetSize, renderer.SheetSize);
+			var framebuffer = renderer.Context.CreateFrameBuffer(size);
 			var sheet = new Sheet(SheetType.BGRA, framebuffer.Texture);
 			mappedBuffers.Add(sheet, framebuffer);

@@ -385,12 +372,6 @@ namespace OpenRA.Mods.Cnc.Traits

 			mappedBuffers.Clear();
 			unmappedBuffers.Clear();
-			renderer.WorldRenderers = renderer.WorldRenderers.Where(r => r != this).ToArray();
-		}
-
-		void INotifyActorDisposing.Disposing(Actor a)
-		{
-			Dispose();
 		}
 	}
 }
--- a/OpenRA.Game/Graphics/ModelVertex.cs
+++ b/OpenRA.Game/Graphics/ModelVertex.cs
@@ -1,53 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright (c) The OpenRA Developers and Contributors
- * This file is part of OpenRA, which is free software. It is made
- * available to you under the terms of the GNU General Public License
- * as published by the Free Software Foundation, either version 3 of
- * the License, or (at your option) any later version. For more
- * information, see COPYING.
- */
-#endregion
-
-using System.Runtime.InteropServices;
-
-namespace OpenRA.Graphics
-{
-	[StructLayout(LayoutKind.Sequential)]
-	public readonly struct ModelVertex
-	{
-		// 3d position
-		public readonly float X, Y, Z;
-
-		// Primary and secondary texture coordinates or RGBA color
-		public readonly float S, T, U, V;
-
-		// Palette and channel flags
-		public readonly float P, C;
-
-		public ModelVertex(in float3 xyz, float s, float t, float u, float v, float p, float c)
-			: this(xyz.X, xyz.Y, xyz.Z, s, t, u, v, p, c) { }
-
-		public ModelVertex(float x, float y, float z, float s, float t, float u, float v, float p, float c)
-		{
-			X = x; Y = y; Z = z;
-			S = s; T = t;
-			U = u; V = v;
-			P = p; C = c;
-		}
-	}
-
-	public sealed class ModelShaderBindings : ShaderBindings
-	{
-		public ModelShaderBindings()
-			: base("model")
-		{ }
-
-		public override ShaderVertexAttribute[] Attributes { get; } = new[]
-		{
-			new ShaderVertexAttribute("aVertexPosition", ShaderVertexAttributeType.Float, 3, 0),
-			new ShaderVertexAttribute("aVertexTexCoord", ShaderVertexAttributeType.Float, 4, 12),
-			new ShaderVertexAttribute("aVertexTexMetadata", ShaderVertexAttributeType.Float, 2, 28),
-		};
-	}
-}
--- a/OpenRA.Game/Graphics/Palette.cs
+++ b/OpenRA.Game/Graphics/Palette.cs
@@ -30,7 +30,7 @@ namespace OpenRA.Graphics

 		public static Color GetColor(this IPalette palette, int index)
 		{
-			return Color.FromArgb(palette[index]);
+			return Color.FromArgb((int)palette[index]);
 		}

 		public static IPalette AsReadOnly(this IPalette palette)
@@ -40,7 +40,7 @@ namespace OpenRA.Graphics
 			return new ReadOnlyPalette(palette);
 		}

-		sealed class ReadOnlyPalette : IPalette
+		class ReadOnlyPalette : IPalette
 		{
 			readonly IPalette palette;
 			public ReadOnlyPalette(IPalette palette) { this.palette = palette; }
@@ -103,7 +103,7 @@ namespace OpenRA.Graphics
 			: this(p)
 		{
 			for (var i = 0; i < Palette.Size; i++)
-				colors[i] = r.GetRemappedColor(this.GetColor(i), i).ToArgb();
+				colors[i] = (uint)r.GetRemappedColor(this.GetColor(i), i).ToArgb();
 		}

 		public ImmutablePalette(IPalette p)
@@ -142,7 +142,7 @@ namespace OpenRA.Graphics

 		public void SetColor(int index, Color color)
 		{
-			colors[index] = color.ToArgb();
+			colors[index] = (uint)color.ToArgb();
 		}

 		public void SetFromPalette(IPalette p)
@@ -153,7 +153,7 @@ namespace OpenRA.Graphics
 		public void ApplyRemap(IPaletteRemap r)
 		{
 			for (var i = 0; i < Palette.Size; i++)
-				colors[i] = r.GetRemappedColor(this.GetColor(i), i).ToArgb();
+				colors[i] = (uint)r.GetRemappedColor(this.GetColor(i), i).ToArgb();
 		}
 	}
 }
--- a/OpenRA.Game/Graphics/PaletteReference.cs
+++ b/OpenRA.Game/Graphics/PaletteReference.cs
@@ -13,17 +13,19 @@ namespace OpenRA.Graphics
 {
 	public sealed class PaletteReference
 	{
+		readonly float index;
 		readonly HardwarePalette hardwarePalette;

 		public readonly string Name;
 		public IPalette Palette { get; internal set; }
-		public int TextureIndex { get; }
+		public float TextureIndex => index / hardwarePalette.Height;
+		public float TextureMidIndex => (index + 0.5f) / hardwarePalette.Height;

 		public PaletteReference(string name, int index, IPalette palette, HardwarePalette hardwarePalette)
 		{
 			Name = name;
 			Palette = palette;
-			TextureIndex = index;
+			this.index = index;
 			this.hardwarePalette = hardwarePalette;
 		}

--- a/OpenRA.Game/Graphics/PlatformInterfaces.cs
+++ b/OpenRA.Game/Graphics/PlatformInterfaces.cs
@@ -20,12 +20,13 @@ namespace OpenRA
 		Automatic,
 		ANGLE,
 		Modern,
-		Embedded
+		Embedded,
+		Legacy
 	}

 	public interface IPlatform
 	{
-		IPlatformWindow CreateWindow(Size size, WindowMode windowMode, float scaleModifier, int vertexBatchSize, int indexBatchSize, int videoDisplay, GLProfile profile);
+		IPlatformWindow CreateWindow(Size size, WindowMode windowMode, float scaleModifier, int batchSize, int videoDisplay, GLProfile profile, bool enableLegacyGL);
 		ISoundEngine CreateSound(string device);
 		IFont CreateFont(byte[] data);
 	}
@@ -82,18 +83,16 @@ namespace OpenRA

 	public interface IGraphicsContext : IDisposable
 	{
-		IVertexBuffer<T> CreateVertexBuffer<T>(int size) where T : struct;
-		T[] CreateVertices<T>(int size) where T : struct;
-		IIndexBuffer CreateIndexBuffer(uint[] indices);
+		IVertexBuffer<Vertex> CreateVertexBuffer(int size);
+		Vertex[] CreateVertices(int size);
 		ITexture CreateTexture();
 		IFrameBuffer CreateFrameBuffer(Size s);
 		IFrameBuffer CreateFrameBuffer(Size s, Color clearColor);
-		IShader CreateShader(IShaderBindings shaderBindings);
+		IShader CreateShader(string name);
 		void EnableScissor(int x, int y, int width, int height);
 		void DisableScissor();
 		void Present();
 		void DrawPrimitives(PrimitiveType pt, int firstVertex, int numVertices);
-		void DrawElements(int numIndices, int offset);
 		void Clear();
 		void EnableDepthBuffer();
 		void DisableDepthBuffer();
@@ -103,14 +102,7 @@ namespace OpenRA
 		string GLVersion { get; }
 	}

-	public interface IRenderer
-	{
-		void BeginFrame();
-		void EndFrame();
-		void SetPalette(HardwarePalette palette);
-	}
-
-	public interface IVertexBuffer<T> : IDisposable where T : struct
+	public interface IVertexBuffer<T> : IDisposable
 	{
 		void Bind();
 		void SetData(T[] vertices, int length);
@@ -122,11 +114,6 @@ namespace OpenRA
 		void SetData(T[] vertices, int offset, int start, int length);
 	}

-	public interface IIndexBuffer : IDisposable
-	{
-		void Bind();
-	}
-
 	public interface IShader
 	{
 		void SetBool(string name, bool value);
@@ -137,17 +124,6 @@ namespace OpenRA
 		void SetTexture(string param, ITexture texture);
 		void SetMatrix(string param, float[] mtx);
 		void PrepareRender();
-		void Bind();
-	}
-
-	public interface IShaderBindings
-	{
-		string VertexShaderName { get; }
-		string VertexShaderCode { get; }
-		string FragmentShaderName { get; }
-		string FragmentShaderCode { get; }
-		int Stride { get; }
-		ShaderVertexAttribute[] Attributes { get; }
 	}

 	public enum TextureScaleFilter { Nearest, Linear }
@@ -156,7 +132,6 @@ namespace OpenRA
 	{
 		void SetData(byte[] colors, int width, int height);
 		void SetFloatData(float[] data, int width, int height);
-		void SetDataFromReadBuffer(Rectangle rect);
 		byte[] GetData();
 		Size Size { get; }
 		TextureScaleFilter ScaleFilter { get; set; }
--- a/OpenRA.Game/Graphics/PlayerColorRemap.cs
+++ b/OpenRA.Game/Graphics/PlayerColorRemap.cs
@@ -20,14 +20,12 @@ namespace OpenRA.Graphics
 		readonly int[] remapIndices;
 		readonly float hue;
 		readonly float saturation;
-		readonly float value;

-		public PlayerColorRemap(int[] remapIndices, Color color)
+		public PlayerColorRemap(int[] remapIndices, float hue, float saturation)
 		{
 			this.remapIndices = remapIndices;
-
-			var (r, g, b) = color.ToLinear();
-			(hue, saturation, value) = Color.RgbToHsv(r, g, b);
+			this.hue = hue;
+			this.saturation = saturation;
 		}

 		public Color GetRemappedColor(Color original, int index)
@@ -44,7 +42,7 @@ namespace OpenRA.Graphics
 			var value = Math.Max(Math.Max(r, g), b);

 			// Construct the new RGB color
-			(r, g, b) = Color.HsvToRgb(hue, saturation, value * this.value);
+			(r, g, b) = Color.HsvToRgb(hue, saturation, value);

 			// Convert linear back to SRGB and pre-multiply by the alpha
 			return Color.FromLinear(original.A, r, g, b);
--- a/OpenRA.Game/Graphics/RenderPostProcessPassVertex.cs
+++ b/OpenRA.Game/Graphics/RenderPostProcessPassVertex.cs
@@ -1,64 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright (c) The OpenRA Developers and Contributors
- * This file is part of OpenRA, which is free software. It is made
- * available to you under the terms of the GNU General Public License
- * as published by the Free Software Foundation, either version 3 of
- * the License, or (at your option) any later version. For more
- * information, see COPYING.
- */
-#endregion
-
-using System.Runtime.InteropServices;
-
-namespace OpenRA.Graphics
-{
-	[StructLayout(LayoutKind.Sequential)]
-	public readonly struct RenderPostProcessPassVertex
-	{
-		public readonly float X, Y;
-
-		public RenderPostProcessPassVertex(float x, float y)
-		{
-			X = x; Y = y;
-		}
-	}
-
-	[StructLayout(LayoutKind.Sequential)]
-	public readonly struct RenderPostProcessPassTexturedVertex
-	{
-		// 3d position
-		public readonly float X, Y;
-		public readonly float S, T;
-
-		public RenderPostProcessPassTexturedVertex(float x, float y, float s, float t)
-		{
-			X = x; Y = y;
-			S = s; T = t;
-		}
-	}
-
-	public sealed class RenderPostProcessPassShaderBindings : ShaderBindings
-	{
-		public RenderPostProcessPassShaderBindings(string name)
-			: base("postprocess", "postprocess_" + name) { }
-
-		public override ShaderVertexAttribute[] Attributes { get; } = new[]
-		{
-			new ShaderVertexAttribute("aVertexPosition", ShaderVertexAttributeType.Float, 2, 0)
-		};
-	}
-
-	public sealed class RenderPostProcessPassTexturedShaderBindings : ShaderBindings
-	{
-		public RenderPostProcessPassTexturedShaderBindings(string name)
-			: base("postprocess_textured", "postprocess_textured_" + name)
-		{ }
-
-		public override ShaderVertexAttribute[] Attributes { get; } = new[]
-		{
-			new ShaderVertexAttribute("aVertexPosition", ShaderVertexAttributeType.Float, 2, 0),
-			new ShaderVertexAttribute("aVertexTexCoord", ShaderVertexAttributeType.Float, 2, 8),
-		};
-	}
-}
--- a/OpenRA.Game/Graphics/RgbaColorRenderer.cs
+++ b/OpenRA.Game/Graphics/RgbaColorRenderer.cs
@@ -18,10 +18,10 @@ namespace OpenRA.Graphics
 {
 	public class RgbaColorRenderer
 	{
-		static readonly float3 Offset = new(0.5f, 0.5f, 0f);
+		static readonly float3 Offset = new float3(0.5f, 0.5f, 0f);

 		readonly SpriteRenderer parent;
-		readonly Vertex[] vertices = new Vertex[4];
+		readonly Vertex[] vertices = new Vertex[6];

 		public RgbaColorRenderer(SpriteRenderer parent)
 		{
@@ -45,12 +45,14 @@ namespace OpenRA.Graphics
 			var eb = endColor.B / 255.0f;
 			var ea = endColor.A / 255.0f;

-			vertices[0] = new Vertex(start - corner + Offset, sr, sg, sb, sa, 0);
-			vertices[1] = new Vertex(start + corner + Offset, sr, sg, sb, sa, 0);
-			vertices[2] = new Vertex(end + corner + Offset, er, eg, eb, ea, 0);
-			vertices[3] = new Vertex(end - corner + Offset, er, eg, eb, ea, 0);
+			vertices[0] = new Vertex(start - corner + Offset, sr, sg, sb, sa, 0, 0);
+			vertices[1] = new Vertex(start + corner + Offset, sr, sg, sb, sa, 0, 0);
+			vertices[2] = new Vertex(end + corner + Offset, er, eg, eb, ea, 0, 0);
+			vertices[3] = new Vertex(end + corner + Offset, er, eg, eb, ea, 0, 0);
+			vertices[4] = new Vertex(end - corner + Offset, er, eg, eb, ea, 0, 0);
+			vertices[5] = new Vertex(start - corner + Offset, sr, sg, sb, sa, 0, 0);

-			parent.DrawRGBAQuad(vertices, blendMode);
+			parent.DrawRGBAVertices(vertices, blendMode);
 		}

 		public void DrawLine(in float3 start, in float3 end, float width, Color color, BlendMode blendMode = BlendMode.Alpha)
@@ -64,19 +66,21 @@ namespace OpenRA.Graphics
 			var b = color.B / 255.0f;
 			var a = color.A / 255.0f;

-			vertices[0] = new Vertex(start - corner + Offset, r, g, b, a, 0);
-			vertices[1] = new Vertex(start + corner + Offset, r, g, b, a, 0);
-			vertices[2] = new Vertex(end + corner + Offset, r, g, b, a, 0);
-			vertices[3] = new Vertex(end - corner + Offset, r, g, b, a, 0);
-			parent.DrawRGBAQuad(vertices, blendMode);
+			vertices[0] = new Vertex(start - corner + Offset, r, g, b, a, 0, 0);
+			vertices[1] = new Vertex(start + corner + Offset, r, g, b, a, 0, 0);
+			vertices[2] = new Vertex(end + corner + Offset, r, g, b, a, 0, 0);
+			vertices[3] = new Vertex(end + corner + Offset, r, g, b, a, 0, 0);
+			vertices[4] = new Vertex(end - corner + Offset, r, g, b, a, 0, 0);
+			vertices[5] = new Vertex(start - corner + Offset, r, g, b, a, 0, 0);
+			parent.DrawRGBAVertices(vertices, blendMode);
 		}

 		/// <summary>
 		/// Calculate the 2D intersection of two lines.
 		/// Will behave badly if the lines are parallel.
-		/// Z position is the average of a and b (ignores actual intersection point if it exists).
+		/// Z position is the average of a and b (ignores actual intersection point if it exists)
 		/// </summary>
-		static float3 IntersectionOf(in float3 a, in float3 da, in float3 b, in float3 db)
+		float3 IntersectionOf(in float3 a, in float3 da, in float3 b, in float3 db)
 		{
 			var crossA = a.X * (a.Y + da.Y) - a.Y * (a.X + da.X);
 			var crossB = b.X * (b.Y + db.Y) - b.Y * (b.X + db.X);
@@ -134,7 +138,7 @@ namespace OpenRA.Graphics
 			// Segment is part of closed loop
 			if (closed)
 			{
-				var prev = points[^1];
+				var prev = points[points.Length - 1];
 				var prevDir = (start - prev) / (start - prev).XY.Length;
 				var prevCorner = width / 2 * new float3(-prevDir.Y, prevDir.X, prevDir.Z);
 				ca = IntersectionOf(start - prevCorner, prevDir, start - corner, dir);
@@ -153,11 +157,13 @@ namespace OpenRA.Graphics
 				var cd = closed || i < limit - 1 ? IntersectionOf(end - corner, dir, end - nextCorner, nextDir) : end - corner;

 				// Fill segment
-				vertices[0] = new Vertex(ca + Offset, r, g, b, a, 0);
-				vertices[1] = new Vertex(cb + Offset, r, g, b, a, 0);
-				vertices[2] = new Vertex(cc + Offset, r, g, b, a, 0);
-				vertices[3] = new Vertex(cd + Offset, r, g, b, a, 0);
-				parent.DrawRGBAQuad(vertices, blendMode);
+				vertices[0] = new Vertex(ca + Offset, r, g, b, a, 0, 0);
+				vertices[1] = new Vertex(cb + Offset, r, g, b, a, 0, 0);
+				vertices[2] = new Vertex(cc + Offset, r, g, b, a, 0, 0);
+				vertices[3] = new Vertex(cc + Offset, r, g, b, a, 0, 0);
+				vertices[4] = new Vertex(cd + Offset, r, g, b, a, 0, 0);
+				vertices[5] = new Vertex(ca + Offset, r, g, b, a, 0, 0);
+				parent.DrawRGBAVertices(vertices, blendMode);

 				// Advance line segment
 				end = next;
@@ -194,6 +200,20 @@ namespace OpenRA.Graphics
 			DrawPolygon(new[] { tl, tr, br, bl }, width, color, blendMode);
 		}

+		public void FillTriangle(in float3 a, in float3 b, in float3 c, Color color, BlendMode blendMode = BlendMode.Alpha)
+		{
+			color = Util.PremultiplyAlpha(color);
+			var cr = color.R / 255.0f;
+			var cg = color.G / 255.0f;
+			var cb = color.B / 255.0f;
+			var ca = color.A / 255.0f;
+
+			vertices[0] = new Vertex(a + Offset, cr, cg, cb, ca, 0, 0);
+			vertices[1] = new Vertex(b + Offset, cr, cg, cb, ca, 0, 0);
+			vertices[2] = new Vertex(c + Offset, cr, cg, cb, ca, 0, 0);
+			parent.DrawRGBAVertices(vertices, blendMode);
+		}
+
 		public void FillRect(in float3 tl, in float3 br, Color color, BlendMode blendMode = BlendMode.Alpha)
 		{
 			var tr = new float3(br.X, tl.Y, tl.Z);
@@ -209,11 +229,13 @@ namespace OpenRA.Graphics
 			var cb = color.B / 255.0f;
 			var ca = color.A / 255.0f;

-			vertices[0] = new Vertex(a + Offset, cr, cg, cb, ca, 0);
-			vertices[1] = new Vertex(b + Offset, cr, cg, cb, ca, 0);
-			vertices[2] = new Vertex(c + Offset, cr, cg, cb, ca, 0);
-			vertices[3] = new Vertex(d + Offset, cr, cg, cb, ca, 0);
-			parent.DrawRGBAQuad(vertices, blendMode);
+			vertices[0] = new Vertex(a + Offset, cr, cg, cb, ca, 0, 0);
+			vertices[1] = new Vertex(b + Offset, cr, cg, cb, ca, 0, 0);
+			vertices[2] = new Vertex(c + Offset, cr, cg, cb, ca, 0, 0);
+			vertices[3] = new Vertex(c + Offset, cr, cg, cb, ca, 0, 0);
+			vertices[4] = new Vertex(d + Offset, cr, cg, cb, ca, 0, 0);
+			vertices[5] = new Vertex(a + Offset, cr, cg, cb, ca, 0, 0);
+			parent.DrawRGBAVertices(vertices, blendMode);
 		}

 		public void FillRect(in float3 a, in float3 b, in float3 c, in float3 d, Color topLeftColor, Color topRightColor, Color bottomRightColor, Color bottomLeftColor, BlendMode blendMode = BlendMode.Alpha)
@@ -221,9 +243,11 @@ namespace OpenRA.Graphics
 			vertices[0] = VertexWithColor(a + Offset, topLeftColor);
 			vertices[1] = VertexWithColor(b + Offset, topRightColor);
 			vertices[2] = VertexWithColor(c + Offset, bottomRightColor);
-			vertices[3] = VertexWithColor(d + Offset, bottomLeftColor);
+			vertices[3] = VertexWithColor(c + Offset, bottomRightColor);
+			vertices[4] = VertexWithColor(d + Offset, bottomLeftColor);
+			vertices[5] = VertexWithColor(a + Offset, topLeftColor);

-			parent.DrawRGBAQuad(vertices, blendMode);
+			parent.DrawRGBAVertices(vertices, blendMode);
 		}

 		static Vertex VertexWithColor(in float3 xyz, Color color)
@@ -234,7 +258,7 @@ namespace OpenRA.Graphics
 			var cb = color.B / 255.0f;
 			var ca = color.A / 255.0f;

-			return new Vertex(xyz, cr, cg, cb, ca, 0);
+			return new Vertex(xyz, cr, cg, cb, ca, 0, 0);
 		}

 		public void FillEllipse(in float3 tl, in float3 br, Color color, BlendMode blendMode = BlendMode.Alpha)
--- a/OpenRA.Game/Graphics/SequenceProvider.cs
+++ b/OpenRA.Game/Graphics/SequenceProvider.cs
@@ -0,0 +1,152 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using OpenRA.FileSystem;
+using OpenRA.Primitives;
+
+namespace OpenRA.Graphics
+{
+	using Sequences = IReadOnlyDictionary<string, Lazy<IReadOnlyDictionary<string, ISpriteSequence>>>;
+	using UnitSequences = Lazy<IReadOnlyDictionary<string, ISpriteSequence>>;
+
+	public interface ISpriteSequence
+	{
+		string Name { get; }
+		int Start { get; }
+		int Length { get; }
+		int Stride { get; }
+		int Facings { get; }
+		int InterpolatedFacings { get; }
+		int Tick { get; }
+		int ZOffset { get; }
+		int ShadowStart { get; }
+		int ShadowZOffset { get; }
+		int[] Frames { get; }
+		Rectangle Bounds { get; }
+		bool IgnoreWorldTint { get; }
+		float Scale { get; }
+
+		Sprite GetSprite(int frame);
+		Sprite GetSprite(int frame, WAngle facing);
+		(Sprite, WAngle) GetSpriteWithRotation(int frame, WAngle facing);
+		Sprite GetShadow(int frame, WAngle facing);
+		float GetAlpha(int frame);
+	}
+
+	public interface ISpriteSequenceLoader
+	{
+		IReadOnlyDictionary<string, ISpriteSequence> ParseSequences(ModData modData, string tileSet, SpriteCache cache, MiniYamlNode node);
+	}
+
+	public class SequenceProvider : IDisposable
+	{
+		readonly ModData modData;
+		readonly string tileSet;
+		readonly Lazy<Sequences> sequences;
+		readonly Lazy<SpriteCache> spriteCache;
+		public SpriteCache SpriteCache => spriteCache.Value;
+
+		readonly Dictionary<string, UnitSequences> sequenceCache = new Dictionary<string, UnitSequences>();
+
+		public SequenceProvider(IReadOnlyFileSystem fileSystem, ModData modData, string tileSet, MiniYaml additionalSequences)
+		{
+			this.modData = modData;
+			this.tileSet = tileSet;
+			sequences = Exts.Lazy(() =>
+			{
+				using (new Support.PerfTimer("LoadSequences"))
+					return Load(fileSystem, additionalSequences);
+			});
+
+			spriteCache = Exts.Lazy(() => new SpriteCache(fileSystem, modData.SpriteLoaders));
+		}
+
+		public ISpriteSequence GetSequence(string unitName, string sequenceName)
+		{
+			if (!sequences.Value.TryGetValue(unitName, out var unitSeq))
+				throw new InvalidOperationException($"Unit `{unitName}` does not have any sequences defined.");
+
+			if (!unitSeq.Value.TryGetValue(sequenceName, out var seq))
+				throw new InvalidOperationException($"Unit `{unitName}` does not have a sequence named `{sequenceName}`");
+
+			return seq;
+		}
+
+		public IEnumerable<string> Images => sequences.Value.Keys;
+
+		public bool HasSequence(string unitName)
+		{
+			return sequences.Value.ContainsKey(unitName);
+		}
+
+		public bool HasSequence(string unitName, string sequenceName)
+		{
+			if (!sequences.Value.TryGetValue(unitName, out var unitSeq))
+				throw new InvalidOperationException($"Unit `{unitName}` does not have any sequences defined.");
+
+			return unitSeq.Value.ContainsKey(sequenceName);
+		}
+
+		public IEnumerable<string> Sequences(string unitName)
+		{
+			if (!sequences.Value.TryGetValue(unitName, out var unitSeq))
+				throw new InvalidOperationException($"Unit `{unitName}` does not have any sequences defined.");
+
+			return unitSeq.Value.Keys;
+		}
+
+		Sequences Load(IReadOnlyFileSystem fileSystem, MiniYaml additionalSequences)
+		{
+			var nodes = MiniYaml.Load(fileSystem, modData.Manifest.Sequences, additionalSequences);
+			var items = new Dictionary<string, UnitSequences>();
+			foreach (var node in nodes)
+			{
+				// Nodes starting with ^ are inheritable but never loaded directly
+				if (node.Key.StartsWith(ActorInfo.AbstractActorPrefix, StringComparison.Ordinal))
+					continue;
+
+				var key = node.Value.ToLines(node.Key).JoinWith("|");
+
+				if (sequenceCache.TryGetValue(key, out var t))
+					items.Add(node.Key, t);
+				else
+				{
+					t = Exts.Lazy(() => modData.SpriteSequenceLoader.ParseSequences(modData, tileSet, SpriteCache, node));
+					sequenceCache.Add(key, t);
+					items.Add(node.Key, t);
+				}
+			}
+
+			return items;
+		}
+
+		public void Preload()
+		{
+			foreach (var sb in SpriteCache.SheetBuilders.Values)
+				sb.Current.CreateBuffer();
+
+			foreach (var unitSeq in sequences.Value.Values)
+				foreach (var seq in unitSeq.Value.Values) { }
+
+			foreach (var sb in SpriteCache.SheetBuilders.Values)
+				sb.Current.ReleaseBuffer();
+		}
+
+		public void Dispose()
+		{
+			if (spriteCache.IsValueCreated)
+				foreach (var sb in SpriteCache.SheetBuilders.Values)
+					sb.Dispose();
+		}
+	}
+}
--- a/OpenRA.Game/Graphics/SequenceSet.cs
+++ b/OpenRA.Game/Graphics/SequenceSet.cs
@@ -1,119 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright (c) The OpenRA Developers and Contributors
- * This file is part of OpenRA, which is free software. It is made
- * available to you under the terms of the GNU General Public License
- * as published by the Free Software Foundation, either version 3 of
- * the License, or (at your option) any later version. For more
- * information, see COPYING.
- */
-#endregion
-
-using System;
-using System.Collections.Generic;
-using OpenRA.FileSystem;
-using OpenRA.Primitives;
-
-namespace OpenRA.Graphics
-{
-	public interface ISpriteSequence
-	{
-		string Name { get; }
-		int Length { get; }
-		int Facings { get; }
-		int Tick { get; }
-		int ZOffset { get; }
-		int ShadowZOffset { get; }
-		Rectangle Bounds { get; }
-		bool IgnoreWorldTint { get; }
-		float Scale { get; }
-		void ResolveSprites(SpriteCache cache);
-		Sprite GetSprite(int frame);
-		Sprite GetSprite(int frame, WAngle facing);
-		(Sprite Sprite, WAngle Rotation) GetSpriteWithRotation(int frame, WAngle facing);
-		Sprite GetShadow(int frame, WAngle facing);
-		float GetAlpha(int frame);
-	}
-
-	public interface ISpriteSequenceLoader
-	{
-		int BgraSheetSize { get; }
-		int IndexedSheetSize { get; }
-		IReadOnlyDictionary<string, ISpriteSequence> ParseSequences(ModData modData, string tileSet, SpriteCache cache, MiniYamlNode node);
-	}
-
-	public sealed class SequenceSet : IDisposable
-	{
-		readonly ModData modData;
-		readonly string tileSet;
-		readonly IReadOnlyDictionary<string, IReadOnlyDictionary<string, ISpriteSequence>> images;
-		public SpriteCache SpriteCache { get; }
-
-		public SequenceSet(IReadOnlyFileSystem fileSystem, ModData modData, string tileSet, MiniYaml additionalSequences)
-		{
-			this.modData = modData;
-			this.tileSet = tileSet;
-			SpriteCache = new SpriteCache(fileSystem, modData.SpriteLoaders, modData.SpriteSequenceLoader.BgraSheetSize, modData.SpriteSequenceLoader.IndexedSheetSize);
-			using (new Support.PerfTimer("LoadSequences"))
-				images = Load(fileSystem, additionalSequences);
-		}
-
-		public ISpriteSequence GetSequence(string image, string sequence)
-		{
-			if (!images.TryGetValue(image, out var sequences))
-				throw new InvalidOperationException($"Image `{image}` does not have any sequences defined.");
-
-			if (!sequences.TryGetValue(sequence, out var seq))
-				throw new InvalidOperationException($"Image `{image}` does not have a sequence named `{sequence}`.");
-
-			return seq;
-		}
-
-		public IEnumerable<string> Images => images.Keys;
-
-		public bool HasSequence(string image, string sequence)
-		{
-			if (!images.TryGetValue(image, out var sequences))
-				throw new InvalidOperationException($"Image `{image}` does not have any sequences defined.");
-
-			return sequences.ContainsKey(sequence);
-		}
-
-		public IEnumerable<string> Sequences(string image)
-		{
-			if (!images.TryGetValue(image, out var sequences))
-				throw new InvalidOperationException($"Image `{image}` does not have any sequences defined.");
-
-			return sequences.Keys;
-		}
-
-		IReadOnlyDictionary<string, IReadOnlyDictionary<string, ISpriteSequence>> Load(IReadOnlyFileSystem fileSystem, MiniYaml additionalSequences)
-		{
-			var nodes = MiniYaml.Load(fileSystem, modData.Manifest.Sequences, additionalSequences);
-			var images = new Dictionary<string, IReadOnlyDictionary<string, ISpriteSequence>>();
-			foreach (var node in nodes)
-			{
-				// Nodes starting with ^ are inheritable but never loaded directly
-				if (node.Key.StartsWith(ActorInfo.AbstractActorPrefix))
-					continue;
-
-				images[node.Key] = modData.SpriteSequenceLoader.ParseSequences(modData, tileSet, SpriteCache, node);
-			}
-
-			return images;
-		}
-
-		public void LoadSprites()
-		{
-			SpriteCache.LoadReservations(modData);
-			foreach (var sequences in images.Values)
-				foreach (var sequence in sequences)
-					sequence.Value.ResolveSprites(SpriteCache);
-		}
-
-		public void Dispose()
-		{
-			SpriteCache.Dispose();
-		}
-	}
-}
--- a/OpenRA.Game/Graphics/ShaderBindings.cs
+++ b/OpenRA.Game/Graphics/ShaderBindings.cs
@@ -1,70 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright (c) The OpenRA Developers and Contributors
- * This file is part of OpenRA, which is free software. It is made
- * available to you under the terms of the GNU General Public License
- * as published by the Free Software Foundation, either version 3 of
- * the License, or (at your option) any later version. For more
- * information, see COPYING.
- */
-#endregion
-
-using System.IO;
-using System.Linq;
-
-namespace OpenRA.Graphics
-{
-	public enum ShaderVertexAttributeType
-	{
-		// Assign the underlying OpenGL type values
-		// to simplify enum use in the shader
-		Float = 0x1406, // GL_FLOAT
-		Int = 0x1404, // GL_INT
-		UInt = 0x1405 // GL_UNSIGNED_INT
-	}
-
-	public readonly struct ShaderVertexAttribute
-	{
-		public readonly string Name;
-		public readonly ShaderVertexAttributeType Type;
-		public readonly int Components;
-		public readonly int Offset;
-
-		public ShaderVertexAttribute(string name, ShaderVertexAttributeType type, int components, int offset)
-		{
-			Name = name;
-			Type = type;
-			Components = components;
-			Offset = offset;
-		}
-	}
-
-	public abstract class ShaderBindings : IShaderBindings
-	{
-		public string VertexShaderName { get; }
-		public string VertexShaderCode { get; }
-		public string FragmentShaderName { get; }
-		public string FragmentShaderCode { get; }
-		public int Stride { get; }
-
-		public abstract ShaderVertexAttribute[] Attributes { get; }
-
-		protected ShaderBindings(string name)
-			: this(name, name) { }
-
-		protected ShaderBindings(string vertexName, string fragmentName)
-		{
-			Stride = Attributes.Sum(a => a.Components * 4);
-			VertexShaderName = vertexName;
-			VertexShaderCode = GetShaderCode(VertexShaderName + ".vert");
-			FragmentShaderName = fragmentName;
-			FragmentShaderCode = GetShaderCode(FragmentShaderName + ".frag");
-		}
-
-		public static string GetShaderCode(string filename)
-		{
-			var filepath = Path.Combine(Platform.EngineDir, "glsl", filename);
-			return File.ReadAllText(filepath);
-		}
-	}
-}
--- a/OpenRA.Game/Graphics/SheetBuilder.cs
+++ b/OpenRA.Game/Graphics/SheetBuilder.cs
@@ -34,16 +34,15 @@ namespace OpenRA.Graphics
 	public sealed class SheetBuilder : IDisposable
 	{
 		public readonly SheetType Type;
-		readonly List<Sheet> sheets = new();
+		readonly List<Sheet> sheets = new List<Sheet>();
 		readonly Func<Sheet> allocateSheet;
 		readonly int margin;
+
+		Sheet current;
+		TextureChannel channel;
 		int rowHeight = 0;
 		int2 p;

-		public Sheet Current { get; private set; }
-		public TextureChannel CurrentChannel { get; private set; }
-		public IEnumerable<Sheet> AllSheets => sheets;
-
 		public static Sheet AllocateSheet(SheetType type, int sheetSize)
 		{
 			return new Sheet(type, new Size(sheetSize, sheetSize));
@@ -74,33 +73,33 @@ namespace OpenRA.Graphics

 		public SheetBuilder(SheetType t, Func<Sheet> allocateSheet, int margin = 1)
 		{
-			CurrentChannel = t == SheetType.Indexed ? TextureChannel.Red : TextureChannel.RGBA;
+			channel = t == SheetType.Indexed ? TextureChannel.Red : TextureChannel.RGBA;
 			Type = t;
-			Current = allocateSheet();
-			sheets.Add(Current);
+			current = allocateSheet();
+			sheets.Add(current);
 			this.allocateSheet = allocateSheet;
 			this.margin = margin;
 		}

-		public Sprite Add(ISpriteFrame frame, bool premultiplied = false) { return Add(frame.Data, frame.Type, frame.Size, 0, frame.Offset, premultiplied); }
-		public Sprite Add(byte[] src, SpriteFrameType type, Size size, bool premultiplied = false) { return Add(src, type, size, 0, float3.Zero, premultiplied); }
-		public Sprite Add(byte[] src, SpriteFrameType type, Size size, float zRamp, in float3 spriteOffset, bool premultiplied = false)
+		public Sprite Add(ISpriteFrame frame) { return Add(frame.Data, frame.Type, frame.Size, 0, frame.Offset); }
+		public Sprite Add(byte[] src, SpriteFrameType type, Size size) { return Add(src, type, size, 0, float3.Zero); }
+		public Sprite Add(byte[] src, SpriteFrameType type, Size size, float zRamp, in float3 spriteOffset)
 		{
 			// Don't bother allocating empty sprites
 			if (size.Width == 0 || size.Height == 0)
-				return new Sprite(Current, Rectangle.Empty, 0, spriteOffset, CurrentChannel, BlendMode.Alpha);
+				return new Sprite(current, Rectangle.Empty, 0, spriteOffset, channel, BlendMode.Alpha);

 			var rect = Allocate(size, zRamp, spriteOffset);
-			Util.FastCopyIntoChannel(rect, src, type, premultiplied);
-			Current.CommitBufferedData();
+			Util.FastCopyIntoChannel(rect, src, type);
+			current.CommitBufferedData();
 			return rect;
 		}

 		public Sprite Add(Png src, float scale = 1f)
 		{
-			var rect = Allocate(new Size(src.Width, src.Height), scale);
+			var rect = Allocate(new Size(src.Width, src.Height),  scale);
 			Util.FastCopyIntoSprite(rect, src);
-			Current.CommitBufferedData();
+			current.CommitBufferedData();
 			return rect;
 		}

@@ -116,7 +115,7 @@ namespace OpenRA.Graphics
 		public Sprite Allocate(Size imageSize, float scale = 1f) { return Allocate(imageSize, 0, float3.Zero, scale); }
 		public Sprite Allocate(Size imageSize, float zRamp, in float3 spriteOffset, float scale = 1f)
 		{
-			if (imageSize.Width + p.X + margin > Current.Size.Width)
+			if (imageSize.Width + p.X + margin > current.Size.Width)
 			{
 				p = new int2(0, p.Y + rowHeight + margin);
 				rowHeight = imageSize.Height;
@@ -125,29 +124,33 @@ namespace OpenRA.Graphics
 			if (imageSize.Height > rowHeight)
 				rowHeight = imageSize.Height;

-			if (p.Y + imageSize.Height + margin > Current.Size.Height)
+			if (p.Y + imageSize.Height + margin > current.Size.Height)
 			{
-				var next = NextChannel(CurrentChannel);
+				var next = NextChannel(channel);
 				if (next == null)
 				{
-					Current.ReleaseBuffer();
-					Current = allocateSheet();
-					sheets.Add(Current);
-					CurrentChannel = Type == SheetType.Indexed ? TextureChannel.Red : TextureChannel.RGBA;
+					current.ReleaseBuffer();
+					current = allocateSheet();
+					sheets.Add(current);
+					channel = Type == SheetType.Indexed ? TextureChannel.Red : TextureChannel.RGBA;
 				}
 				else
-					CurrentChannel = next.Value;
+					channel = next.Value;

 				rowHeight = imageSize.Height;
 				p = int2.Zero;
 			}

-			var rect = new Sprite(Current, new Rectangle(p.X + margin, p.Y + margin, imageSize.Width, imageSize.Height), zRamp, spriteOffset, CurrentChannel, BlendMode.Alpha, scale);
+			var rect = new Sprite(current, new Rectangle(p.X + margin, p.Y + margin, imageSize.Width, imageSize.Height), zRamp, spriteOffset, channel, BlendMode.Alpha, scale);
 			p += new int2(imageSize.Width + margin, 0);

 			return rect;
 		}

+		public Sheet Current => current;
+		public TextureChannel CurrentChannel => channel;
+		public IEnumerable<Sheet> AllSheets => sheets;
+
 		public void Dispose()
 		{
 			foreach (var sheet in sheets)
--- a/OpenRA.Game/Graphics/Sprite.cs
+++ b/OpenRA.Game/Graphics/Sprite.cs
@@ -42,11 +42,11 @@ namespace OpenRA.Graphics
 			// in rendering a line of texels that sample outside the sprite rectangle.
 			// Insetting the texture coordinates by a small fraction of a pixel avoids this
 			// with negligible impact on the 1:1 rendering case.
-			const float Inset = 1 / 128f;
-			Left = (Math.Min(bounds.Left, bounds.Right) + Inset) / sheet.Size.Width;
-			Top = (Math.Min(bounds.Top, bounds.Bottom) + Inset) / sheet.Size.Height;
-			Right = (Math.Max(bounds.Left, bounds.Right) - Inset) / sheet.Size.Width;
-			Bottom = (Math.Max(bounds.Top, bounds.Bottom) - Inset) / sheet.Size.Height;
+			var inset = 1 / 128f;
+			Left = (Math.Min(bounds.Left, bounds.Right) + inset) / sheet.Size.Width;
+			Top = (Math.Min(bounds.Top, bounds.Bottom) + inset) / sheet.Size.Height;
+			Right = (Math.Max(bounds.Left, bounds.Right) - inset) / sheet.Size.Width;
+			Bottom = (Math.Max(bounds.Top, bounds.Bottom) - inset) / sheet.Size.Height;
 		}
 	}

--- a/OpenRA.Game/Graphics/SpriteCache.cs
+++ b/OpenRA.Game/Graphics/SpriteCache.cs
@@ -1,170 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright (c) The OpenRA Developers and Contributors
- * This file is part of OpenRA, which is free software. It is made
- * available to you under the terms of the GNU General Public License
- * as published by the Free Software Foundation, either version 3 of
- * the License, or (at your option) any later version. For more
- * information, see COPYING.
- */
-#endregion
-
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using OpenRA.FileSystem;
-using OpenRA.Primitives;
-
-namespace OpenRA.Graphics
-{
-	public sealed class SpriteCache : IDisposable
-	{
-		public readonly Dictionary<SheetType, SheetBuilder> SheetBuilders;
-		readonly ISpriteLoader[] loaders;
-		readonly IReadOnlyFileSystem fileSystem;
-
-		readonly Dictionary<int, (int[] Frames, MiniYamlNode.SourceLocation Location, Func<ISpriteFrame, ISpriteFrame> AdjustFrame, bool Premultiplied)> spriteReservations = new();
-		readonly Dictionary<string, List<int>> reservationsByFilename = new();
-
-		readonly Dictionary<int, Sprite[]> resolvedSprites = new();
-
-		readonly Dictionary<int, (string Filename, MiniYamlNode.SourceLocation Location)> missingFiles = new();
-
-		int nextReservationToken = 1;
-
-		public SpriteCache(IReadOnlyFileSystem fileSystem, ISpriteLoader[] loaders, int bgraSheetSize, int indexedSheetSize, int bgraSheetMargin = 1, int indexedSheetMargin = 1)
-		{
-			SheetBuilders = new Dictionary<SheetType, SheetBuilder>
-			{
-				{ SheetType.Indexed, new SheetBuilder(SheetType.Indexed, indexedSheetSize, indexedSheetMargin) },
-				{ SheetType.BGRA, new SheetBuilder(SheetType.BGRA, bgraSheetSize, bgraSheetMargin) }
-			};
-
-			this.fileSystem = fileSystem;
-			this.loaders = loaders;
-		}
-
-		public int ReserveSprites(string filename, IEnumerable<int> frames, MiniYamlNode.SourceLocation location, Func<ISpriteFrame, ISpriteFrame> adjustFrame = null, bool premultiplied = false)
-		{
-			var token = nextReservationToken++;
-			spriteReservations[token] = (frames?.ToArray(), location, adjustFrame, premultiplied);
-			reservationsByFilename.GetOrAdd(filename, _ => new List<int>()).Add(token);
-			return token;
-		}
-
-		static ISpriteFrame[] GetFrames(IReadOnlyFileSystem fileSystem, string filename, ISpriteLoader[] loaders, out TypeDictionary metadata)
-		{
-			metadata = null;
-			if (!fileSystem.TryOpen(filename, out var stream))
-				return null;
-
-			using (stream)
-			{
-				foreach (var loader in loaders)
-					if (loader.TryParseSprite(stream, filename, out var frames, out metadata))
-						return frames;
-
-				return null;
-			}
-		}
-
-		public void LoadReservations(ModData modData)
-		{
-			foreach (var sb in SheetBuilders.Values)
-				sb.Current.CreateBuffer();
-
-			var pendingResolve = new List<(
-				string Filename,
-				int FrameIndex,
-				bool Premultiplied,
-				Func<ISpriteFrame, ISpriteFrame> AdjustFrame,
-				ISpriteFrame Frame,
-				Sprite[] SpritesForToken)>();
-			foreach (var (filename, tokens) in reservationsByFilename)
-			{
-				modData.LoadScreen?.Display();
-				var loadedFrames = GetFrames(fileSystem, filename, loaders, out _);
-				foreach (var token in tokens)
-				{
-					if (spriteReservations.TryGetValue(token, out var rs))
-					{
-						if (loadedFrames != null)
-						{
-							var resolved = new Sprite[loadedFrames.Length];
-							resolvedSprites[token] = resolved;
-							var frames = rs.Frames ?? Enumerable.Range(0, loadedFrames.Length);
-
-							foreach (var i in frames)
-							{
-								var frame = loadedFrames[i];
-								if (rs.AdjustFrame != null)
-									frame = rs.AdjustFrame(frame);
-								pendingResolve.Add((filename, i, rs.Premultiplied, rs.AdjustFrame, frame, resolved));
-							}
-						}
-						else
-						{
-							resolvedSprites[token] = null;
-							missingFiles[token] = (filename, rs.Location);
-						}
-					}
-				}
-			}
-
-			spriteReservations.Clear();
-			spriteReservations.TrimExcess();
-			reservationsByFilename.Clear();
-			reservationsByFilename.TrimExcess();
-
-			// When the sheet builder is adding sprites, it reserves height for the tallest sprite seen along the row.
-			// We can achieve better sheet packing by keeping sprites with similar heights together.
-			var orderedPendingResolve = pendingResolve.OrderBy(x => x.Frame.Size.Height);
-
-			var spriteCache = new Dictionary<(
-				string Filename,
-				int FrameIndex,
-				bool Premultiplied,
-				Func<ISpriteFrame, ISpriteFrame> AdjustFrame),
-				Sprite>(pendingResolve.Count);
-			foreach (var (filename, frameIndex, premultiplied, adjustFrame, frame, spritesForToken) in orderedPendingResolve)
-			{
-				// Premultiplied and non-premultiplied sprites must be cached separately
-				// to cover the case where the same image is requested in both versions.
-				spritesForToken[frameIndex] = spriteCache.GetOrAdd(
-					(filename, frameIndex, premultiplied, adjustFrame),
-					_ =>
-					{
-						var sheetBuilder = SheetBuilders[SheetBuilder.FrameTypeToSheetType(frame.Type)];
-						return sheetBuilder.Add(frame, premultiplied);
-					});
-
-				modData.LoadScreen?.Display();
-			}
-
-			foreach (var sb in SheetBuilders.Values)
-				sb.Current.ReleaseBuffer();
-		}
-
-		public Sprite[] ResolveSprites(int token)
-		{
-			if (!resolvedSprites.Remove(token, out var resolved))
-				throw new InvalidOperationException($"{nameof(token)} {token} has either already been resolved, or was never reserved via {nameof(ReserveSprites)}");
-
-			resolvedSprites.TrimExcess();
-
-			if (missingFiles.TryGetValue(token, out var r))
-				throw new FileNotFoundException($"{r.Location}: {r.Filename} not found", r.Filename);
-
-			return resolved;
-		}
-
-		public IEnumerable<(string Filename, MiniYamlNode.SourceLocation Location)> MissingFiles => missingFiles.Values.ToHashSet();
-
-		public void Dispose()
-		{
-			foreach (var sb in SheetBuilders.Values)
-				sb.Dispose();
-		}
-	}
-}
--- a/OpenRA.Game/Graphics/SpriteFont.cs
+++ b/OpenRA.Game/Graphics/SpriteFont.cs
@@ -123,7 +123,7 @@ namespace OpenRA.Graphics
 			}
 		}

-		static float2 Rotate(float2 v, float sina, float cosa, float2 offset)
+		float2 Rotate(float2 v, float sina, float cosa, float2 offset)
 		{
 			return new float2(
 				v.X * cosa - v.Y * sina + offset.X,
@@ -427,7 +427,7 @@ namespace OpenRA.Graphics
 		}
 	}

-	sealed class GlyphInfo
+	class GlyphInfo
 	{
 		public float Advance;
 		public int2 Offset;
--- a/OpenRA.Game/Graphics/SpriteLoader.cs
+++ b/OpenRA.Game/Graphics/SpriteLoader.cs
@@ -9,7 +9,10 @@
 */
 #endregion

+using System;
+using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using OpenRA.FileSystem;
 using OpenRA.Primitives;

@@ -18,34 +21,24 @@ namespace OpenRA.Graphics
 	/// <summary>
 	/// Describes the format of the pixel data in a ISpriteFrame.
 	/// Note that the channel order is defined for little-endian bytes, so BGRA corresponds
-	/// to a 32bit ARGB value, such as that returned by Color.ToArgb().
+	/// to a 32bit ARGB value, such as that returned by Color.ToArgb()!
 	/// </summary>
 	public enum SpriteFrameType
 	{
-		/// <summary>
-		/// 8 bit index into an external palette.
-		/// </summary>
+		// 8 bit index into an external palette
 		Indexed8,

-		/// <summary>
-		/// 32 bit color such as returned by Color.ToArgb() or the bmp file format
-		/// (remember that little-endian systems place the little bits in the first byte).
-		/// </summary>
+		// 32 bit color such as returned by Color.ToArgb() or the bmp file format
+		// (remember that little-endian systems place the little bits in the first byte!)
 		Bgra32,

-		/// <summary>
-		/// Like BGRA, but without an alpha channel.
-		/// </summary>
+		// Like BGRA, but without an alpha channel
 		Bgr24,

-		/// <summary>
-		/// 32 bit color in big-endian format, like png.
-		/// </summary>
+		// 32 bit color in big-endian format, like png
 		Rgba32,

-		/// <summary>
-		/// Like RGBA, but without an alpha channel.
-		/// </summary>
+		// Like RGBA, but without an alpha channel
 		Rgb24
 	}

@@ -74,6 +67,94 @@ namespace OpenRA.Graphics
 		bool DisableExportPadding { get; }
 	}

+	public class SpriteCache
+	{
+		public readonly Cache<SheetType, SheetBuilder> SheetBuilders;
+		readonly ISpriteLoader[] loaders;
+		readonly IReadOnlyFileSystem fileSystem;
+
+		readonly Dictionary<string, List<Sprite[]>> sprites = new Dictionary<string, List<Sprite[]>>();
+		readonly Dictionary<string, ISpriteFrame[]> unloadedFrames = new Dictionary<string, ISpriteFrame[]>();
+		readonly Dictionary<string, TypeDictionary> metadata = new Dictionary<string, TypeDictionary>();
+
+		public SpriteCache(IReadOnlyFileSystem fileSystem, ISpriteLoader[] loaders)
+		{
+			SheetBuilders = new Cache<SheetType, SheetBuilder>(t => new SheetBuilder(t));
+
+			this.fileSystem = fileSystem;
+			this.loaders = loaders;
+		}
+
+		/// <summary>
+		/// Returns the first set of sprites with the given filename.
+		/// If getUsedFrames is defined then the indices returned by the function call
+		/// are guaranteed to be loaded.  The value of other indices in the returned
+		/// array are undefined and should never be accessed.
+		/// </summary>
+		public Sprite[] this[string filename, Func<int, IEnumerable<int>> getUsedFrames = null]
+		{
+			get
+			{
+				var allSprites = sprites.GetOrAdd(filename);
+				var sprite = allSprites.FirstOrDefault();
+
+				if (!unloadedFrames.TryGetValue(filename, out var unloaded))
+					unloaded = null;
+
+				// This is the first time that the file has been requested
+				// Load all of the frames into the unused buffer and initialize
+				// the loaded cache (initially empty)
+				if (sprite == null)
+				{
+					unloaded = FrameLoader.GetFrames(fileSystem, filename, loaders, out var fileMetadata);
+					unloadedFrames[filename] = unloaded;
+					metadata[filename] = fileMetadata;
+
+					sprite = new Sprite[unloaded.Length];
+					allSprites.Add(sprite);
+				}
+
+				// HACK: The sequence code relies on side-effects from getUsedFrames
+				var indices = getUsedFrames != null ? getUsedFrames(sprite.Length) :
+					Enumerable.Range(0, sprite.Length);
+
+				// Load any unused frames into the SheetBuilder
+				if (unloaded != null)
+				{
+					foreach (var i in indices)
+					{
+						if (unloaded[i] != null)
+						{
+							sprite[i] = SheetBuilders[SheetBuilder.FrameTypeToSheetType(unloaded[i].Type)].Add(unloaded[i]);
+							unloaded[i] = null;
+						}
+					}
+
+					// All frames have been loaded
+					if (unloaded.All(f => f == null))
+						unloadedFrames.Remove(filename);
+				}
+
+				return sprite;
+			}
+		}
+
+		/// <summary>
+		/// Returns a TypeDictionary containing any metadata defined by the frame
+		/// or null if the frame does not define metadata.
+		/// </summary>
+		public TypeDictionary FrameMetadata(string filename)
+		{
+			if (!metadata.TryGetValue(filename, out var fileMetadata))
+			{
+				FrameLoader.GetFrames(fileSystem, filename, loaders, out fileMetadata);
+				metadata[filename] = fileMetadata;
+			}
+
+			return fileMetadata;
+		}
+	}
+
 	public class FrameCache
 	{
 		readonly Cache<string, ISpriteFrame[]> frames;
--- a/OpenRA.Game/Graphics/SpriteRenderable.cs
+++ b/OpenRA.Game/Graphics/SpriteRenderable.cs
@@ -21,95 +21,102 @@ namespace OpenRA.Graphics

 		readonly Sprite sprite;
 		readonly WPos pos;
+		readonly WVec offset;
+		readonly int zOffset;
+		readonly PaletteReference palette;
 		readonly float scale;
 		readonly WAngle rotation = WAngle.Zero;
+		readonly float3 tint;
+		readonly TintModifiers tintModifiers;
+		readonly float alpha;
+		readonly bool isDecoration;

 		public SpriteRenderable(Sprite sprite, WPos pos, WVec offset, int zOffset, PaletteReference palette, float scale, float alpha,
 			float3 tint, TintModifiers tintModifiers, bool isDecoration, WAngle rotation)
 		{
 			this.sprite = sprite;
 			this.pos = pos;
-			Offset = offset;
-			ZOffset = zOffset;
-			Palette = palette;
+			this.offset = offset;
+			this.zOffset = zOffset;
+			this.palette = palette;
 			this.scale = scale;
 			this.rotation = rotation;
-			Tint = tint;
-			IsDecoration = isDecoration;
-			TintModifiers = tintModifiers;
-			Alpha = alpha;
+			this.tint = tint;
+			this.isDecoration = isDecoration;
+			this.tintModifiers = tintModifiers;
+			this.alpha = alpha;

 			// PERF: Remove useless palette assignments for RGBA sprites
 			// HACK: This is working around the fact that palettes are defined on traits rather than sequences
 			// and can be removed once this has been fixed
 			if (sprite.Channel == TextureChannel.RGBA && !(palette?.HasColorShift ?? false))
-				Palette = null;
+				this.palette = null;
 		}

 		public SpriteRenderable(Sprite sprite, WPos pos, WVec offset, int zOffset, PaletteReference palette, float scale, float alpha,
 			float3 tint, TintModifiers tintModifiers, bool isDecoration)
 			: this(sprite, pos, offset, zOffset, palette, scale, alpha, tint, tintModifiers, isDecoration, WAngle.Zero) { }

-		public WPos Pos => pos + Offset;
-		public WVec Offset { get; }
-		public PaletteReference Palette { get; }
-		public int ZOffset { get; }
-		public bool IsDecoration { get; }
+		public WPos Pos => pos + offset;
+		public WVec Offset => offset;
+		public PaletteReference Palette => palette;
+		public int ZOffset => zOffset;
+		public bool IsDecoration => isDecoration;

-		public float Alpha { get; }
-		public float3 Tint { get; }
-		public TintModifiers TintModifiers { get; }
+		public float Alpha => alpha;
+		public float3 Tint => tint;
+		public TintModifiers TintModifiers => tintModifiers;

 		public IPalettedRenderable WithPalette(PaletteReference newPalette)
 		{
-			return new SpriteRenderable(sprite, pos, Offset, ZOffset, newPalette, scale, Alpha, Tint, TintModifiers, IsDecoration, rotation);
+			return new SpriteRenderable(sprite, pos, offset, zOffset, newPalette, scale, alpha, tint, tintModifiers, isDecoration, rotation);
 		}

 		public IRenderable WithZOffset(int newOffset)
 		{
-			return new SpriteRenderable(sprite, pos, Offset, newOffset, Palette, scale, Alpha, Tint, TintModifiers, IsDecoration, rotation);
+			return new SpriteRenderable(sprite, pos, offset, newOffset, palette, scale, alpha, tint, tintModifiers, isDecoration, rotation);
 		}

 		public IRenderable OffsetBy(in WVec vec)
 		{
-			return new SpriteRenderable(sprite, pos + vec, Offset, ZOffset, Palette, scale, Alpha, Tint, TintModifiers, IsDecoration, rotation);
+			return new SpriteRenderable(sprite, pos + vec, offset, zOffset, palette, scale, alpha, tint, tintModifiers, isDecoration, rotation);
 		}

 		public IRenderable AsDecoration()
 		{
-			return new SpriteRenderable(sprite, pos, Offset, ZOffset, Palette, scale, Alpha, Tint, TintModifiers, true, rotation);
+			return new SpriteRenderable(sprite, pos, offset, zOffset, palette, scale, alpha, tint, tintModifiers, true, rotation);
 		}

 		public IModifyableRenderable WithAlpha(float newAlpha)
 		{
-			return new SpriteRenderable(sprite, pos, Offset, ZOffset, Palette, scale, newAlpha, Tint, TintModifiers, IsDecoration, rotation);
+			return new SpriteRenderable(sprite, pos, offset, zOffset, palette, scale, newAlpha, tint, tintModifiers, isDecoration, rotation);
 		}

 		public IModifyableRenderable WithTint(in float3 newTint, TintModifiers newTintModifiers)
 		{
-			return new SpriteRenderable(sprite, pos, Offset, ZOffset, Palette, scale, Alpha, newTint, newTintModifiers, IsDecoration, rotation);
+			return new SpriteRenderable(sprite, pos, offset, zOffset, palette, scale, alpha, newTint, newTintModifiers, isDecoration, rotation);
 		}

 		float3 ScreenPosition(WorldRenderer wr)
 		{
 			var s = 0.5f * scale * sprite.Size;
-			return wr.Screen3DPxPosition(pos) + wr.ScreenPxOffset(Offset) - new float3((int)s.X, (int)s.Y, s.Z);
+			return wr.Screen3DPxPosition(pos) + wr.ScreenPxOffset(offset) - new float3((int)s.X, (int)s.Y, s.Z);
 		}

 		public IFinalizedRenderable PrepareRender(WorldRenderer wr) { return this; }
 		public void Render(WorldRenderer wr)
 		{
 			var wsr = Game.Renderer.WorldSpriteRenderer;
-			var t = Alpha * Tint;
-			if (wr.TerrainLighting != null && (TintModifiers & TintModifiers.IgnoreWorldTint) == 0)
+			var t = alpha * tint;
+			if (wr.TerrainLighting != null && (tintModifiers & TintModifiers.IgnoreWorldTint) == 0)
 				t *= wr.TerrainLighting.TintAt(pos);

 			// Shader interprets negative alpha as a flag to use the tint colour directly instead of multiplying the sprite colour
-			var a = Alpha;
-			if ((TintModifiers & TintModifiers.ReplaceColor) != 0)
+			var a = alpha;
+			if ((tintModifiers & TintModifiers.ReplaceColor) != 0)
 				a *= -1;

-			wsr.DrawSprite(sprite, Palette, ScreenPosition(wr), scale, t, a, rotation.RendererRadians());
+			wsr.DrawSprite(sprite, palette, ScreenPosition(wr), scale, t, a, rotation.RendererRadians());
 		}

 		public void RenderDebugGeometry(WorldRenderer wr)
--- a/OpenRA.Game/Graphics/SpriteRenderer.cs
+++ b/OpenRA.Game/Graphics/SpriteRenderer.cs
@@ -11,7 +11,6 @@

 using System;
 using System.Collections.Generic;
-using System.Runtime.InteropServices;
 using OpenRA.Primitives;

 namespace OpenRA.Graphics
@@ -20,7 +19,6 @@ namespace OpenRA.Graphics
 	{
 		public const int SheetCount = 8;
 		static readonly string[] SheetIndexToTextureName = Exts.MakeArray(SheetCount, i => $"Texture{i}");
-		static readonly int UintSize = Marshal.SizeOf(typeof(uint));

 		readonly Renderer renderer;
 		readonly IShader shader;
@@ -29,21 +27,21 @@ namespace OpenRA.Graphics
 		readonly Sheet[] sheets = new Sheet[SheetCount];

 		BlendMode currentBlend = BlendMode.Alpha;
-		int vertexCount = 0;
-		int sheetCount = 0;
+		int nv = 0;
+		int ns = 0;

 		public SpriteRenderer(Renderer renderer, IShader shader)
 		{
 			this.renderer = renderer;
 			this.shader = shader;
-			vertices = renderer.Context.CreateVertices<Vertex>(renderer.TempVertexBufferSize);
+			vertices = renderer.Context.CreateVertices(renderer.TempBufferSize);
 		}

 		public void Flush()
 		{
-			if (vertexCount > 0)
+			if (nv > 0)
 			{
-				for (var i = 0; i < sheetCount; i++)
+				for (var i = 0; i < ns; i++)
 				{
 					shader.SetTexture(SheetIndexToTextureName[i], sheets[i].GetTexture());
 					sheets[i] = null;
@@ -52,11 +50,12 @@ namespace OpenRA.Graphics
 				renderer.Context.SetBlendMode(currentBlend);
 				shader.PrepareRender();

-				renderer.DrawQuadBatch(ref vertices, shader, vertexCount);
+				// PERF: The renderer may choose to replace vertices with a different temporary buffer.
+				renderer.DrawBatch(ref vertices, nv, PrimitiveType.TriangleList);
 				renderer.Context.SetBlendMode(BlendMode.None);

-				vertexCount = 0;
-				sheetCount = 0;
+				nv = 0;
+				ns = 0;
 			}
 		}

@@ -64,7 +63,7 @@ namespace OpenRA.Graphics
 		{
 			renderer.CurrentBatchRenderer = this;

-			if (s.BlendMode != currentBlend || vertexCount + 4 > renderer.TempVertexBufferSize)
+			if (s.BlendMode != currentBlend || nv + 6 > renderer.TempBufferSize)
 				Flush();

 			currentBlend = s.BlendMode;
@@ -72,7 +71,7 @@ namespace OpenRA.Graphics
 			// Check if the sheet (or secondary data sheet) have already been mapped
 			var sheet = s.Sheet;
 			var sheetIndex = 0;
-			for (; sheetIndex < sheetCount; sheetIndex++)
+			for (; sheetIndex < ns; sheetIndex++)
 				if (sheets[sheetIndex] == sheet)
 					break;

@@ -81,7 +80,7 @@ namespace OpenRA.Graphics
 			if (ss != null)
 			{
 				var secondarySheet = ss.SecondarySheet;
-				for (; secondarySheetIndex < sheetCount; secondarySheetIndex++)
+				for (; secondarySheetIndex < ns; secondarySheetIndex++)
 					if (sheets[secondarySheetIndex] == secondarySheet)
 						break;

@@ -100,22 +99,22 @@ namespace OpenRA.Graphics
 				secondarySheetIndex = ss != null && ss.SecondarySheet != sheet ? 1 : 0;
 			}

-			if (sheetIndex >= sheetCount)
+			if (sheetIndex >= ns)
 			{
 				sheets[sheetIndex] = sheet;
-				sheetCount++;
+				ns++;
 			}

-			if (secondarySheetIndex >= sheetCount && ss != null)
+			if (secondarySheetIndex >= ns && ss != null)
 			{
 				sheets[secondarySheetIndex] = ss.SecondarySheet;
-				sheetCount++;
+				ns++;
 			}

 			return new int2(sheetIndex, secondarySheetIndex);
 		}

-		static int ResolveTextureIndex(Sprite s, PaletteReference pal)
+		float ResolveTextureIndex(Sprite s, PaletteReference pal)
 		{
 			if (pal == null)
 				return 0;
@@ -129,20 +128,20 @@ namespace OpenRA.Graphics
 			return pal.TextureIndex;
 		}

-		internal void DrawSprite(Sprite s, int paletteTextureIndex, in float3 location, in float3 scale, float rotation = 0f)
+		internal void DrawSprite(Sprite s, float paletteTextureIndex, in float3 location, in float3 scale, float rotation = 0f)
 		{
 			var samplers = SetRenderStateForSprite(s);
-			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, vertexCount, scale * s.Size, float3.Ones,
+			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, nv, scale * s.Size, float3.Ones,
 								1f, rotation);
-			vertexCount += 4;
+			nv += 6;
 		}

-		internal void DrawSprite(Sprite s, int paletteTextureIndex, in float3 location, float scale, float rotation = 0f)
+		internal void DrawSprite(Sprite s, float paletteTextureIndex, in float3 location, float scale, float rotation = 0f)
 		{
 			var samplers = SetRenderStateForSprite(s);
-			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, vertexCount, scale * s.Size, float3.Ones,
+			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, nv, scale * s.Size, float3.Ones,
 								1f, rotation);
-			vertexCount += 4;
+			nv += 6;
 		}

 		public void DrawSprite(Sprite s, PaletteReference pal, in float3 location, float scale = 1f, float rotation = 0f)
@@ -150,13 +149,13 @@ namespace OpenRA.Graphics
 			DrawSprite(s, ResolveTextureIndex(s, pal), location, scale, rotation);
 		}

-		internal void DrawSprite(Sprite s, int paletteTextureIndex, in float3 location, float scale, in float3 tint, float alpha,
+		internal void DrawSprite(Sprite s, float paletteTextureIndex, in float3 location, float scale, in float3 tint, float alpha,
 			float rotation = 0f)
 		{
 			var samplers = SetRenderStateForSprite(s);
-			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, vertexCount, scale * s.Size, tint, alpha,
+			Util.FastCreateQuad(vertices, location + scale * s.Offset, s, samplers, paletteTextureIndex, nv, scale * s.Size, tint, alpha,
 								rotation);
-			vertexCount += 4;
+			nv += 6;
 		}

 		public void DrawSprite(Sprite s, PaletteReference pal, in float3 location, float scale, in float3 tint, float alpha,
@@ -165,14 +164,14 @@ namespace OpenRA.Graphics
 			DrawSprite(s, ResolveTextureIndex(s, pal), location, scale, tint, alpha, rotation);
 		}

-		internal void DrawSprite(Sprite s, int paletteTextureIndex, in float3 a, in float3 b, in float3 c, in float3 d, in float3 tint, float alpha)
+		internal void DrawSprite(Sprite s, float paletteTextureIndex, in float3 a, in float3 b, in float3 c, in float3 d, in float3 tint, float alpha)
 		{
 			var samplers = SetRenderStateForSprite(s);
-			Util.FastCreateQuad(vertices, a, b, c, d, s, samplers, paletteTextureIndex, tint, alpha, vertexCount);
-			vertexCount += 4;
+			Util.FastCreateQuad(vertices, a, b, c, d, s, samplers, paletteTextureIndex, tint, alpha, nv);
+			nv += 6;
 		}

-		public void DrawVertexBuffer(IVertexBuffer<Vertex> buffer, IIndexBuffer indices, int start, int length, IEnumerable<Sheet> sheets, BlendMode blendMode)
+		public void DrawVertexBuffer(IVertexBuffer<Vertex> buffer, int start, int length, PrimitiveType type, IEnumerable<Sheet> sheets, BlendMode blendMode)
 		{
 			var i = 0;
 			foreach (var s in sheets)
@@ -186,7 +185,7 @@ namespace OpenRA.Graphics

 			renderer.Context.SetBlendMode(blendMode);
 			shader.PrepareRender();
-			renderer.DrawQuadBatch(buffer, indices, shader, length, UintSize * start);
+			renderer.DrawBatch(buffer, start, length, type);
 			renderer.Context.SetBlendMode(BlendMode.None);
 		}

@@ -197,32 +196,29 @@ namespace OpenRA.Graphics
 		}

 		// For RGBAColorRenderer
-		internal void DrawRGBAQuad(Vertex[] v, BlendMode blendMode)
+		internal void DrawRGBAVertices(Vertex[] v, BlendMode blendMode)
 		{
 			renderer.CurrentBatchRenderer = this;

-			if (currentBlend != blendMode || vertexCount + 4 > renderer.TempVertexBufferSize)
+			if (currentBlend != blendMode || nv + v.Length > renderer.TempBufferSize)
 				Flush();

 			currentBlend = blendMode;
-
-			Array.Copy(v, 0, vertices, vertexCount, v.Length);
-			vertexCount += 4;
+			Array.Copy(v, 0, vertices, nv, v.Length);
+			nv += v.Length;
 		}

-		public void SetPalette(HardwarePalette palette)
+		public void SetPalette(ITexture palette, ITexture colorShifts)
 		{
-			shader.SetTexture("Palette", palette.Texture);
-			shader.SetTexture("ColorShifts", palette.ColorShifts);
-			shader.SetVec("PaletteRows", palette.Height);
+			shader.SetTexture("Palette", palette);
+			shader.SetTexture("ColorShifts", colorShifts);
 		}

 		public void SetViewportParams(Size sheetSize, int downscale, float depthMargin, int2 scroll)
 		{
-			// OpenGL only renders x and y coordinates inside [-1, 1] range. We project world coordinates
-			// using p1 to values [0, 2] and then subtract by 1 using p2, where p stands for projection. It's
-			// standard practice for shaders to use a projection matrix, but as we project orthographically
-			// we are able to send less data to the GPU.
+			// Calculate the scale (r1) and offset (r2) that convert from OpenRA viewport pixels
+			// to OpenGL normalized device coordinates (NDC). OpenGL expects coordinates to vary from [-1, 1],
+			// so we rescale viewport pixels to the range [0, 2] using r1 then subtract 1 using r2.
 			var width = 2f / (downscale * sheetSize.Width);
 			var height = 2f / (downscale * sheetSize.Height);

@@ -243,8 +239,8 @@ namespace OpenRA.Graphics
 			var depth = depthMargin != 0f ? 2f / (downscale * (sheetSize.Height + depthMargin)) : 0;
 			shader.SetVec("DepthTextureScale", 128 * depth);
 			shader.SetVec("Scroll", scroll.X, scroll.Y, depthMargin != 0f ? scroll.Y : 0);
-			shader.SetVec("p1", width, height, -depth);
-			shader.SetVec("p2", -1, -1, depthMargin != 0f ? 1 : 0);
+			shader.SetVec("r1", width, height, -depth);
+			shader.SetVec("r2", -1, -1, depthMargin != 0f ? 1 : 0);
 		}

 		public void SetDepthPreview(bool enabled, float contrast, float offset)
--- a/OpenRA.Game/Graphics/TerrainSpriteLayer.cs
+++ b/OpenRA.Game/Graphics/TerrainSpriteLayer.cs
@@ -12,15 +12,12 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Runtime.CompilerServices;

 namespace OpenRA.Graphics
 {
 	public sealed class TerrainSpriteLayer : IDisposable
 	{
-		// PERF: we can reuse the IndexBuffer as all layers have the same size.
-		static readonly ConditionalWeakTable<World, IndexBufferRc> IndexBuffers = new();
-		readonly IndexBufferRc indexBufferWrapper;
+		static readonly int[] CornerVertexMap = { 0, 1, 2, 2, 3, 0 };

 		public readonly BlendMode BlendMode;

@@ -30,9 +27,8 @@ namespace OpenRA.Graphics
 		readonly IVertexBuffer<Vertex> vertexBuffer;
 		readonly Vertex[] vertices;
 		readonly bool[] ignoreTint;
-		readonly HashSet<int> dirtyRows = new();
-		readonly int indexRowStride;
-		readonly int vertexRowStride;
+		readonly HashSet<int> dirtyRows = new HashSet<int>();
+		readonly int rowStride;
 		readonly bool restrictToBounds;

 		readonly WorldRenderer worldRenderer;
@@ -47,25 +43,19 @@ namespace OpenRA.Graphics
 			this.emptySprite = emptySprite;
 			sheets = new Sheet[SpriteRenderer.SheetCount];
 			BlendMode = blendMode;
+
 			map = world.Map;
+			rowStride = 6 * map.MapSize.X;

-			vertexRowStride = 4 * map.MapSize.X;
-			vertices = new Vertex[vertexRowStride * map.MapSize.Y];
-			vertexBuffer = Game.Renderer.Context.CreateVertexBuffer<Vertex>(vertices.Length);
-
-			indexRowStride = 6 * map.MapSize.X;
-			lock (IndexBuffers)
-			{
-				indexBufferWrapper = IndexBuffers.GetValue(world, world => new IndexBufferRc(world));
-				indexBufferWrapper.AddRef();
-			}
-
+			vertices = new Vertex[rowStride * map.MapSize.Y];
 			palettes = new PaletteReference[map.MapSize.X * map.MapSize.Y];
+			vertexBuffer = Game.Renderer.Context.CreateVertexBuffer(vertices.Length);
+
 			wr.PaletteInvalidated += UpdatePaletteIndices;

 			if (wr.TerrainLighting != null)
 			{
-				ignoreTint = new bool[vertexRowStride * map.MapSize.Y];
+				ignoreTint = new bool[rowStride * map.MapSize.Y];
 				wr.TerrainLighting.CellChanged += UpdateTint;
 			}
 		}
@@ -75,9 +65,8 @@ namespace OpenRA.Graphics
 			for (var i = 0; i < vertices.Length; i++)
 			{
 				var v = vertices[i];
-				var p = palettes[i / 4]?.TextureIndex ?? 0;
-				var c = (uint)((p & 0xFFFF) << 16) | (v.C & 0xFFFF);
-				vertices[i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, c, v.R, v.G, v.B, v.A);
+				var p = palettes[i / 6]?.TextureIndex ?? 0;
+				vertices[i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, p, v.C, v.R, v.G, v.B, v.A);
 			}

 			for (var row = 0; row < map.MapSize.Y; row++)
@@ -108,13 +97,13 @@ namespace OpenRA.Graphics

 		void UpdateTint(MPos uv)
 		{
-			var offset = vertexRowStride * uv.V + 4 * uv.U;
+			var offset = rowStride * uv.V + 6 * uv.U;
 			if (ignoreTint[offset])
 			{
-				for (var i = 0; i < 4; i++)
+				for (var i = 0; i < 6; i++)
 				{
 					var v = vertices[offset + i];
-					vertices[offset + i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, v.C, v.A * float3.Ones, v.A);
+					vertices[offset + i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, v.P, v.C, v.A * float3.Ones, v.A);
 				}

 				return;
@@ -125,7 +114,7 @@ namespace OpenRA.Graphics
 			// transparent for isometric tiles
 			var tl = worldRenderer.TerrainLighting;
 			var pos = map.CenterOfCell(uv.ToCPos(map));
-			var step = map.Grid.TileScale / 2;
+			var step = map.Grid.Type == MapGridType.RectangularIsometric ? 724 : 512;
 			var weights = new[]
 			{
 				tl.TintAt(pos + new WVec(-step, -step, 0)),
@@ -136,10 +125,10 @@ namespace OpenRA.Graphics

 			// Apply tint directly to the underlying vertices
 			// This saves us from having to re-query the sprite information, which has not changed
-			for (var i = 0; i < 4; i++)
+			for (var i = 0; i < 6; i++)
 			{
 				var v = vertices[offset + i];
-				vertices[offset + i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, v.C, v.A * weights[i], v.A);
+				vertices[offset + i] = new Vertex(v.X, v.Y, v.Z, v.S, v.T, v.U, v.V, v.P, v.C, v.A * weights[CornerVertexMap[i]], v.A);
 			}

 			dirtyRows.Add(uv.V);
@@ -191,7 +180,7 @@ namespace OpenRA.Graphics
 			if (!map.Tiles.Contains(uv))
 				return;

-			var offset = vertexRowStride * uv.V + 4 * uv.U;
+			var offset = rowStride * uv.V + 6 * uv.U;
 			Util.FastCreateQuad(vertices, pos, sprite, samplers, palette?.TextureIndex ?? 0, offset, scale * sprite.Size, alpha * float3.Ones, alpha);
 			palettes[uv.V * map.MapSize.X + uv.U] = palette;

@@ -220,13 +209,13 @@ namespace OpenRA.Graphics
 				if (!dirtyRows.Remove(row))
 					continue;

-				var rowOffset = vertexRowStride * row;
-				vertexBuffer.SetData(vertices, rowOffset, rowOffset, vertexRowStride);
+				var rowOffset = rowStride * row;
+				vertexBuffer.SetData(vertices, rowOffset, rowOffset, rowStride);
 			}

 			Game.Renderer.WorldSpriteRenderer.DrawVertexBuffer(
-				vertexBuffer, indexBufferWrapper.Buffer, indexRowStride * firstRow,
-				indexRowStride * (lastRow - firstRow), sheets, BlendMode);
+				vertexBuffer, rowStride * firstRow, rowStride * (lastRow - firstRow),
+				PrimitiveType.TriangleList, sheets, BlendMode);

 			Game.Renderer.Flush();
 		}
@@ -238,29 +227,6 @@ namespace OpenRA.Graphics
 				worldRenderer.TerrainLighting.CellChanged -= UpdateTint;

 			vertexBuffer.Dispose();
-
-			lock (IndexBuffers)
-				indexBufferWrapper.Dispose();
-		}
-
-		sealed class IndexBufferRc : IDisposable
-		{
-			public IIndexBuffer Buffer;
-			int count;
-
-			public IndexBufferRc(World world)
-			{
-				Buffer = Game.Renderer.Context.CreateIndexBuffer(Util.CreateQuadIndices(world.Map.MapSize.X * world.Map.MapSize.Y));
-			}
-
-			public void AddRef() { count++; }
-
-			public void Dispose()
-			{
-				count--;
-				if (count == 0)
-					Buffer.Dispose();
-			}
 		}
 	}
 }
--- a/OpenRA.Game/Graphics/UISpriteRenderable.cs
+++ b/OpenRA.Game/Graphics/UISpriteRenderable.cs
@@ -16,7 +16,10 @@ namespace OpenRA.Graphics
 	public class UISpriteRenderable : IRenderable, IPalettedRenderable, IFinalizedRenderable
 	{
 		readonly Sprite sprite;
+		readonly WPos effectiveWorldPos;
 		readonly int2 screenPos;
+		readonly int zOffset;
+		readonly PaletteReference palette;
 		readonly float scale;
 		readonly float alpha;
 		readonly float rotation = 0f;
@@ -24,10 +27,10 @@ namespace OpenRA.Graphics
 		public UISpriteRenderable(Sprite sprite, WPos effectiveWorldPos, int2 screenPos, int zOffset, PaletteReference palette, float scale = 1f, float alpha = 1f, float rotation = 0f)
 		{
 			this.sprite = sprite;
-			Pos = effectiveWorldPos;
+			this.effectiveWorldPos = effectiveWorldPos;
 			this.screenPos = screenPos;
-			ZOffset = zOffset;
-			Palette = palette;
+			this.zOffset = zOffset;
+			this.palette = palette;
 			this.scale = scale;
 			this.alpha = alpha;
 			this.rotation = rotation;
@@ -36,18 +39,18 @@ namespace OpenRA.Graphics
 			// HACK: This is working around the fact that palettes are defined on traits rather than sequences
 			// and can be removed once this has been fixed
 			if (sprite.Channel == TextureChannel.RGBA && !(palette?.HasColorShift ?? false))
-				Palette = null;
+				this.palette = null;
 		}

 		// Does not exist in the world, so a world positions don't make sense
-		public WPos Pos { get; }
+		public WPos Pos => effectiveWorldPos;
 		public WVec Offset => WVec.Zero;
 		public bool IsDecoration => true;

-		public PaletteReference Palette { get; }
-		public int ZOffset { get; }
+		public PaletteReference Palette => palette;
+		public int ZOffset => zOffset;

-		public IPalettedRenderable WithPalette(PaletteReference newPalette) { return new UISpriteRenderable(sprite, Pos, screenPos, ZOffset, newPalette, scale, alpha, rotation); }
+		public IPalettedRenderable WithPalette(PaletteReference newPalette) { return new UISpriteRenderable(sprite, effectiveWorldPos, screenPos, zOffset, newPalette, scale, alpha, rotation); }
 		public IRenderable WithZOffset(int newOffset) { return this; }
 		public IRenderable OffsetBy(in WVec vec) { return this; }
 		public IRenderable AsDecoration() { return this; }
@@ -55,7 +58,7 @@ namespace OpenRA.Graphics
 		public IFinalizedRenderable PrepareRender(WorldRenderer wr) { return this; }
 		public void Render(WorldRenderer wr)
 		{
-			Game.Renderer.SpriteRenderer.DrawSprite(sprite, Palette, screenPos, scale, float3.Ones, alpha, rotation);
+			Game.Renderer.SpriteRenderer.DrawSprite(sprite, palette, screenPos, scale, float3.Ones, alpha, rotation);
 		}

 		public void RenderDebugGeometry(WorldRenderer wr)
--- a/OpenRA.Game/Graphics/Util.cs
+++ b/OpenRA.Game/Graphics/Util.cs
@@ -10,7 +10,6 @@
 #endregion

 using System;
-using System.Runtime.InteropServices;
 using OpenRA.FileFormats;
 using OpenRA.Primitives;

@@ -21,17 +20,7 @@ namespace OpenRA.Graphics
 		// yes, our channel order is nuts.
 		static readonly int[] ChannelMasks = { 2, 1, 0, 3 };

-		public static uint[] CreateQuadIndices(int quads)
-		{
-			var indices = new uint[quads * 6];
-			ReadOnlySpan<uint> cornerVertexMap = stackalloc uint[] { 0, 1, 2, 2, 3, 0 };
-			for (var i = 0; i < indices.Length; i++)
-				indices[i] = cornerVertexMap[i % 6] + (uint)(4 * (i / 6));
-
-			return indices;
-		}
-
-		public static void FastCreateQuad(Vertex[] vertices, in float3 o, Sprite r, int2 samplers, int paletteTextureIndex, int nv,
+		public static void FastCreateQuad(Vertex[] vertices, in float3 o, Sprite r, int2 samplers, float paletteTextureIndex, int nv,
 			in float3 size, in float3 tint, float alpha, float rotation = 0f)
 		{
 			float3 a, b, c, d;
@@ -73,7 +62,7 @@ namespace OpenRA.Graphics

 		public static void FastCreateQuad(Vertex[] vertices,
 			in float3 a, in float3 b, in float3 c, in float3 d,
-			Sprite r, int2 samplers, int paletteTextureIndex,
+			Sprite r, int2 samplers, float paletteTextureIndex,
 			in float3 tint, float alpha, int nv)
 		{
 			float sl = 0;
@@ -95,33 +84,76 @@ namespace OpenRA.Graphics
 				attribC |= samplers.Y << 9;
 			}

-			attribC |= (paletteTextureIndex & 0xFFFF) << 16;
-
-			var uAttribC = (uint)attribC;
-			vertices[nv] = new Vertex(a, r.Left, r.Top, sl, st, uAttribC, tint, alpha);
-			vertices[nv + 1] = new Vertex(b, r.Right, r.Top, sr, st, uAttribC, tint, alpha);
-			vertices[nv + 2] = new Vertex(c, r.Right, r.Bottom, sr, sb, uAttribC, tint, alpha);
-			vertices[nv + 3] = new Vertex(d, r.Left, r.Bottom, sl, sb, uAttribC, tint, alpha);
+			var fAttribC = (float)attribC;
+			vertices[nv] = new Vertex(a, r.Left, r.Top, sl, st, paletteTextureIndex, fAttribC, tint, alpha);
+			vertices[nv + 1] = new Vertex(b, r.Right, r.Top, sr, st, paletteTextureIndex, fAttribC, tint, alpha);
+			vertices[nv + 2] = new Vertex(c, r.Right, r.Bottom, sr, sb, paletteTextureIndex, fAttribC, tint, alpha);
+			vertices[nv + 3] = new Vertex(c, r.Right, r.Bottom, sr, sb, paletteTextureIndex, fAttribC, tint, alpha);
+			vertices[nv + 4] = new Vertex(d, r.Left, r.Bottom, sl, sb, paletteTextureIndex, fAttribC, tint, alpha);
+			vertices[nv + 5] = new Vertex(a, r.Left, r.Top, sl, st, paletteTextureIndex, fAttribC, tint, alpha);
 		}

-		public static void FastCopyIntoChannel(Sprite dest, byte[] src, SpriteFrameType srcType, bool premultiplied = false)
+		public static void FastCopyIntoChannel(Sprite dest, byte[] src, SpriteFrameType srcType)
 		{
 			var destData = dest.Sheet.GetData();
-			var stride = dest.Sheet.Size.Width;
-			var x = dest.Bounds.Left;
-			var y = dest.Bounds.Top;
 			var width = dest.Bounds.Width;
 			var height = dest.Bounds.Height;

 			if (dest.Channel == TextureChannel.RGBA)
 			{
-				CopyIntoRgba(src, srcType, premultiplied, destData, x, y, width, height, stride);
+				var destStride = dest.Sheet.Size.Width;
+				unsafe
+				{
+					// Cast the data to an int array so we can copy the src data directly
+					fixed (byte* bd = &destData[0])
+					{
+						var data = (int*)bd;
+						var x = dest.Bounds.Left;
+						var y = dest.Bounds.Top;
+
+						var k = 0;
+						for (var j = 0; j < height; j++)
+						{
+							for (var i = 0; i < width; i++)
+							{
+								byte r, g, b, a;
+								switch (srcType)
+								{
+									case SpriteFrameType.Bgra32:
+									case SpriteFrameType.Bgr24:
+									{
+										b = src[k++];
+										g = src[k++];
+										r = src[k++];
+										a = srcType == SpriteFrameType.Bgra32 ? src[k++] : (byte)255;
+										break;
+									}
+
+									case SpriteFrameType.Rgba32:
+									case SpriteFrameType.Rgb24:
+									{
+										r = src[k++];
+										g = src[k++];
+										b = src[k++];
+										a = srcType == SpriteFrameType.Rgba32 ? src[k++] : (byte)255;
+										break;
+									}
+
+									default:
+										throw new InvalidOperationException($"Unknown SpriteFrameType {srcType}");
+								}
+
+								var cc = Color.FromArgb(a, r, g, b);
+								data[(y + j) * destStride + x + i] = PremultiplyAlpha(cc).ToArgb();
+							}
+						}
+					}
+				}
 			}
 			else
 			{
-				// Copy into single channel of destination.
-				var destStride = stride * 4;
-				var destOffset = destStride * y + x * 4 + ChannelMasks[(int)dest.Channel];
+				var destStride = dest.Sheet.Size.Width * 4;
+				var destOffset = destStride * dest.Bounds.Top + dest.Bounds.Left * 4 + ChannelMasks[(int)dest.Channel];
 				var destSkip = destStride - 4 * width;

 				var srcOffset = 0;
@@ -138,127 +170,64 @@ namespace OpenRA.Graphics
 			}
 		}

-		static void CopyIntoRgba(
-			byte[] src, SpriteFrameType srcType, bool premultiplied, byte[] dest, int x, int y, int width, int height, int stride)
-		{
-			var si = 0;
-			var di = y * stride + x;
-			var d = MemoryMarshal.Cast<byte, uint>(dest);
-
-			// SpriteFrameType.Brga32 is a common source format, and it matches the destination format.
-			// Provide a fast past that just performs memory copies.
-			if (srcType == SpriteFrameType.Bgra32)
-			{
-				var s = MemoryMarshal.Cast<byte, uint>(src);
-				for (var h = 0; h < height; h++)
-				{
-					s[si..(si + width)].CopyTo(d[di..(di + width)]);
-
-					if (!premultiplied)
-					{
-						for (var w = 0; w < width; w++)
-						{
-							d[di] = PremultiplyAlpha(Color.FromArgb(d[di])).ToArgb();
-							di++;
-						}
-
-						di -= width;
-					}
-
-					si += width;
-					di += stride;
-				}
-
-				return;
-			}
-
-			for (var h = 0; h < height; h++)
-			{
-				for (var w = 0; w < width; w++)
-				{
-					byte r, g, b, a;
-					switch (srcType)
-					{
-						case SpriteFrameType.Bgra32:
-						case SpriteFrameType.Bgr24:
-							b = src[si++];
-							g = src[si++];
-							r = src[si++];
-							a = srcType == SpriteFrameType.Bgra32 ? src[si++] : byte.MaxValue;
-							break;
-
-						case SpriteFrameType.Rgba32:
-						case SpriteFrameType.Rgb24:
-							r = src[si++];
-							g = src[si++];
-							b = src[si++];
-							a = srcType == SpriteFrameType.Rgba32 ? src[si++] : byte.MaxValue;
-							break;
-
-						default:
-							throw new InvalidOperationException($"Unknown SpriteFrameType {srcType}");
-					}
-
-					var c = Color.FromArgb(a, r, g, b);
-					if (!premultiplied)
-						c = PremultiplyAlpha(c);
-					d[di++] = c.ToArgb();
-				}
-
-				di += stride - width;
-			}
-		}
-
 		public static void FastCopyIntoSprite(Sprite dest, Png src)
 		{
 			var destData = dest.Sheet.GetData();
-			var stride = dest.Sheet.Size.Width;
-			var x = dest.Bounds.Left;
-			var y = dest.Bounds.Top;
+			var destStride = dest.Sheet.Size.Width;
 			var width = dest.Bounds.Width;
 			var height = dest.Bounds.Height;

-			var si = 0;
-			var di = y * stride + x;
-			var d = MemoryMarshal.Cast<byte, uint>(destData);
-
-			for (var h = 0; h < height; h++)
+			unsafe
 			{
-				for (var w = 0; w < width; w++)
+				// Cast the data to an int array so we can copy the src data directly
+				fixed (byte* bd = &destData[0])
 				{
-					Color c;
-					switch (src.Type)
+					var data = (int*)bd;
+					var x = dest.Bounds.Left;
+					var y = dest.Bounds.Top;
+
+					var k = 0;
+					for (var j = 0; j < height; j++)
 					{
-						case SpriteFrameType.Indexed8:
-							c = src.Palette[src.Data[si++]];
-							break;
+						for (var i = 0; i < width; i++)
+						{
+							Color cc;
+							switch (src.Type)
+							{
+								case SpriteFrameType.Indexed8:
+								{
+									cc = src.Palette[src.Data[k++]];
+									break;
+								}

-						case SpriteFrameType.Rgba32:
-						case SpriteFrameType.Rgb24:
-							var r = src.Data[si++];
-							var g = src.Data[si++];
-							var b = src.Data[si++];
-							var a = src.Type == SpriteFrameType.Rgba32 ? src.Data[si++] : byte.MaxValue;
-							c = Color.FromArgb(a, r, g, b);
-							break;
+								case SpriteFrameType.Rgba32:
+								case SpriteFrameType.Rgb24:
+								{
+									var r = src.Data[k++];
+									var g = src.Data[k++];
+									var b = src.Data[k++];
+									var a = src.Type == SpriteFrameType.Rgba32 ? src.Data[k++] : (byte)255;
+									cc = Color.FromArgb(a, r, g, b);
+									break;
+								}

-						// PNGs don't support BGR[A], so no need to include them here
-						default:
-							throw new InvalidOperationException($"Unknown SpriteFrameType {src.Type}");
+								// Pngs don't support BGR[A], so no need to include them here
+								default:
+									throw new InvalidOperationException($"Unknown SpriteFrameType {src.Type}");
+							}
+
+							data[(y + j) * destStride + x + i] = PremultiplyAlpha(cc).ToArgb();
+						}
 					}
-
-					d[di++] = PremultiplyAlpha(c).ToArgb();
 				}
-
-				di += stride - width;
 			}
 		}

 		/// <summary>Rotates a quad about its center in the x-y plane.</summary>
-		/// <param name="tl">The top left vertex of the quad.</param>
-		/// <param name="size">A float3 containing the X, Y, and Z lengths of the quad.</param>
-		/// <param name="rotation">The number of radians to rotate by.</param>
-		/// <returns>An array of four vertices representing the rotated quad (top-left, top-right, bottom-right, bottom-left).</returns>
+		/// <param name="tl">The top left vertex of the quad</param>
+		/// <param name="size">A float3 containing the X, Y, and Z lengths of the quad</param>
+		/// <param name="rotation">The number of radians to rotate by</param>
+		/// <returns>An array of four vertices representing the rotated quad (top-left, top-right, bottom-right, bottom-left)</returns>
 		public static float3[] RotateQuad(float3 tl, float3 size, float rotation)
 		{
 			var center = tl + 0.5f * size;
@@ -289,15 +258,15 @@ namespace OpenRA.Graphics
 		/// <summary>
 		/// Returns the bounds of an object. Used for determining which objects need to be rendered on screen, and which do not.
 		/// </summary>
-		/// <param name="offset">The top left vertex of the object.</param>
-		/// <param name="size">A float 3 containing the X, Y, and Z lengths of the object.</param>
-		/// <param name="rotation">The angle to rotate the object by (use 0f if there is no rotation).</param>
+		/// <param name="offset">The top left vertex of the object</param>
+		/// <param name="size">A float 3 containing the X, Y, and Z lengths of the object</param>
+		/// <param name="rotation">The angle to rotate the object by (use 0f if there is no rotation)</param>
 		public static Rectangle BoundingRectangle(float3 offset, float3 size, float rotation)
 		{
 			if (rotation == 0f)
 				return new Rectangle((int)offset.X, (int)offset.Y, (int)size.X, (int)size.Y);

-			var rotatedQuad = RotateQuad(offset, size, rotation);
+			var rotatedQuad = Util.RotateQuad(offset, size, rotation);
 			var minX = rotatedQuad[0].X;
 			var maxX = rotatedQuad[0].X;
 			var minY = rotatedQuad[0].Y;
@@ -336,5 +305,239 @@ namespace OpenRA.Graphics
 				(int)((byte)(t * a2 * c2.G + 0.5f) + (1 - t) * (byte)(a1 * c1.G + 0.5f)),
 				(int)((byte)(t * a2 * c2.B + 0.5f) + (1 - t) * (byte)(a1 * c1.B + 0.5f))));
 		}
+
+		public static float[] IdentityMatrix()
+		{
+			return Exts.MakeArray(16, j => (j % 5 == 0) ? 1.0f : 0);
+		}
+
+		public static float[] ScaleMatrix(float sx, float sy, float sz)
+		{
+			var mtx = IdentityMatrix();
+			mtx[0] = sx;
+			mtx[5] = sy;
+			mtx[10] = sz;
+			return mtx;
+		}
+
+		public static float[] TranslationMatrix(float x, float y, float z)
+		{
+			var mtx = IdentityMatrix();
+			mtx[12] = x;
+			mtx[13] = y;
+			mtx[14] = z;
+			return mtx;
+		}
+
+		public static float[] MatrixMultiply(float[] lhs, float[] rhs)
+		{
+			var mtx = new float[16];
+			for (var i = 0; i < 4; i++)
+				for (var j = 0; j < 4; j++)
+				{
+					mtx[4 * i + j] = 0;
+					for (var k = 0; k < 4; k++)
+						mtx[4 * i + j] += lhs[4 * k + j] * rhs[4 * i + k];
+				}
+
+			return mtx;
+		}
+
+		public static float[] MatrixVectorMultiply(float[] mtx, float[] vec)
+		{
+			var ret = new float[4];
+			for (var j = 0; j < 4; j++)
+			{
+				ret[j] = 0;
+				for (var k = 0; k < 4; k++)
+					ret[j] += mtx[4 * k + j] * vec[k];
+			}
+
+			return ret;
+		}
+
+		public static float[] MatrixInverse(float[] m)
+		{
+			var mtx = new float[16];
+
+			mtx[0] = m[5] * m[10] * m[15] -
+				m[5] * m[11] * m[14] -
+				m[9] * m[6] * m[15] +
+				m[9] * m[7] * m[14] +
+				m[13] * m[6] * m[11] -
+				m[13] * m[7] * m[10];
+
+			mtx[4] = -m[4] * m[10] * m[15] +
+				m[4] * m[11] * m[14] +
+				m[8] * m[6] * m[15] -
+				m[8] * m[7] * m[14] -
+				m[12] * m[6] * m[11] +
+				m[12] * m[7] * m[10];
+
+			mtx[8] = m[4] * m[9] * m[15] -
+				m[4] * m[11] * m[13] -
+				m[8] * m[5] * m[15] +
+				m[8] * m[7] * m[13] +
+				m[12] * m[5] * m[11] -
+				m[12] * m[7] * m[9];
+
+			mtx[12] = -m[4] * m[9] * m[14] +
+				m[4] * m[10] * m[13] +
+				m[8] * m[5] * m[14] -
+				m[8] * m[6] * m[13] -
+				m[12] * m[5] * m[10] +
+				m[12] * m[6] * m[9];
+
+			mtx[1] = -m[1] * m[10] * m[15] +
+				m[1] * m[11] * m[14] +
+				m[9] * m[2] * m[15] -
+				m[9] * m[3] * m[14] -
+				m[13] * m[2] * m[11] +
+				m[13] * m[3] * m[10];
+
+			mtx[5] = m[0] * m[10] * m[15] -
+				m[0] * m[11] * m[14] -
+				m[8] * m[2] * m[15] +
+				m[8] * m[3] * m[14] +
+				m[12] * m[2] * m[11] -
+				m[12] * m[3] * m[10];
+
+			mtx[9] = -m[0] * m[9] * m[15] +
+				m[0] * m[11] * m[13] +
+				m[8] * m[1] * m[15] -
+				m[8] * m[3] * m[13] -
+				m[12] * m[1] * m[11] +
+				m[12] * m[3] * m[9];
+
+			mtx[13] = m[0] * m[9] * m[14] -
+				m[0] * m[10] * m[13] -
+				m[8] * m[1] * m[14] +
+				m[8] * m[2] * m[13] +
+				m[12] * m[1] * m[10] -
+				m[12] * m[2] * m[9];
+
+			mtx[2] = m[1] * m[6] * m[15] -
+				m[1] * m[7] * m[14] -
+				m[5] * m[2] * m[15] +
+				m[5] * m[3] * m[14] +
+				m[13] * m[2] * m[7] -
+				m[13] * m[3] * m[6];
+
+			mtx[6] = -m[0] * m[6] * m[15] +
+				m[0] * m[7] * m[14] +
+				m[4] * m[2] * m[15] -
+				m[4] * m[3] * m[14] -
+				m[12] * m[2] * m[7] +
+				m[12] * m[3] * m[6];
+
+			mtx[10] = m[0] * m[5] * m[15] -
+				m[0] * m[7] * m[13] -
+				m[4] * m[1] * m[15] +
+				m[4] * m[3] * m[13] +
+				m[12] * m[1] * m[7] -
+				m[12] * m[3] * m[5];
+
+			mtx[14] = -m[0] * m[5] * m[14] +
+				m[0] * m[6] * m[13] +
+				m[4] * m[1] * m[14] -
+				m[4] * m[2] * m[13] -
+				m[12] * m[1] * m[6] +
+				m[12] * m[2] * m[5];
+
+			mtx[3] = -m[1] * m[6] * m[11] +
+				m[1] * m[7] * m[10] +
+				m[5] * m[2] * m[11] -
+				m[5] * m[3] * m[10] -
+				m[9] * m[2] * m[7] +
+				m[9] * m[3] * m[6];
+
+			mtx[7] = m[0] * m[6] * m[11] -
+				m[0] * m[7] * m[10] -
+				m[4] * m[2] * m[11] +
+				m[4] * m[3] * m[10] +
+				m[8] * m[2] * m[7] -
+				m[8] * m[3] * m[6];
+
+			mtx[11] = -m[0] * m[5] * m[11] +
+				m[0] * m[7] * m[9] +
+				m[4] * m[1] * m[11] -
+				m[4] * m[3] * m[9] -
+				m[8] * m[1] * m[7] +
+				m[8] * m[3] * m[5];
+
+			mtx[15] = m[0] * m[5] * m[10] -
+				m[0] * m[6] * m[9] -
+				m[4] * m[1] * m[10] +
+				m[4] * m[2] * m[9] +
+				m[8] * m[1] * m[6] -
+				m[8] * m[2] * m[5];
+
+			var det = m[0] * mtx[0] + m[1] * mtx[4] + m[2] * mtx[8] + m[3] * mtx[12];
+			if (det == 0)
+				return null;
+
+			for (var i = 0; i < 16; i++)
+				mtx[i] *= 1 / det;
+
+			return mtx;
+		}
+
+		public static float[] MakeFloatMatrix(Int32Matrix4x4 imtx)
+		{
+			var multipler = 1f / imtx.M44;
+			return new[]
+			{
+				imtx.M11 * multipler,
+				imtx.M12 * multipler,
+				imtx.M13 * multipler,
+				imtx.M14 * multipler,
+
+				imtx.M21 * multipler,
+				imtx.M22 * multipler,
+				imtx.M23 * multipler,
+				imtx.M24 * multipler,
+
+				imtx.M31 * multipler,
+				imtx.M32 * multipler,
+				imtx.M33 * multipler,
+				imtx.M34 * multipler,
+
+				imtx.M41 * multipler,
+				imtx.M42 * multipler,
+				imtx.M43 * multipler,
+				imtx.M44 * multipler,
+			};
+		}
+
+		public static float[] MatrixAABBMultiply(float[] mtx, float[] bounds)
+		{
+			// Corner offsets
+			var ix = new uint[] { 0, 0, 0, 0, 3, 3, 3, 3 };
+			var iy = new uint[] { 1, 1, 4, 4, 1, 1, 4, 4 };
+			var iz = new uint[] { 2, 5, 2, 5, 2, 5, 2, 5 };
+
+			// Vectors to opposing corner
+			var ret = new[]
+			{
+				float.MaxValue, float.MaxValue, float.MaxValue,
+				float.MinValue, float.MinValue, float.MinValue
+			};
+
+			// Transform vectors and find new bounding box
+			for (var i = 0; i < 8; i++)
+			{
+				var vec = new[] { bounds[ix[i]], bounds[iy[i]], bounds[iz[i]], 1 };
+				var tvec = MatrixVectorMultiply(mtx, vec);
+
+				ret[0] = Math.Min(ret[0], tvec[0] / tvec[3]);
+				ret[1] = Math.Min(ret[1], tvec[1] / tvec[3]);
+				ret[2] = Math.Min(ret[2], tvec[2] / tvec[3]);
+				ret[3] = Math.Max(ret[3], tvec[0] / tvec[3]);
+				ret[4] = Math.Max(ret[4], tvec[1] / tvec[3]);
+				ret[5] = Math.Max(ret[5], tvec[2] / tvec[3]);
+			}
+
+			return ret;
+		}
 	}
 }
--- a/OpenRA.Game/Graphics/Vertex.cs
+++ b/OpenRA.Game/Graphics/Vertex.cs
@@ -23,42 +23,27 @@ namespace OpenRA.Graphics
 		public readonly float S, T, U, V;

 		// Palette and channel flags
-		public readonly uint C;
+		public readonly float P, C;

 		// Color tint
 		public readonly float R, G, B, A;

-		public Vertex(in float3 xyz, float s, float t, float u, float v, uint c)
-			: this(xyz.X, xyz.Y, xyz.Z, s, t, u, v, c, float3.Ones, 1f) { }
+		public Vertex(in float3 xyz, float s, float t, float u, float v, float p, float c)
+			: this(xyz.X, xyz.Y, xyz.Z, s, t, u, v, p, c, float3.Ones, 1f) { }

-		public Vertex(in float3 xyz, float s, float t, float u, float v, uint c, in float3 tint, float a)
-			: this(xyz.X, xyz.Y, xyz.Z, s, t, u, v, c, tint.X, tint.Y, tint.Z, a) { }
+		public Vertex(in float3 xyz, float s, float t, float u, float v, float p, float c, in float3 tint, float a)
+			: this(xyz.X, xyz.Y, xyz.Z, s, t, u, v, p, c, tint.X, tint.Y, tint.Z, a) { }

-		public Vertex(float x, float y, float z, float s, float t, float u, float v, uint c, in float3 tint, float a)
-			: this(x, y, z, s, t, u, v, c, tint.X, tint.Y, tint.Z, a) { }
+		public Vertex(float x, float y, float z, float s, float t, float u, float v, float p, float c, in float3 tint, float a)
+			: this(x, y, z, s, t, u, v, p, c, tint.X, tint.Y, tint.Z, a) { }

-		public Vertex(float x, float y, float z, float s, float t, float u, float v, uint c, float r, float g, float b, float a)
+		public Vertex(float x, float y, float z, float s, float t, float u, float v, float p, float c, float r, float g, float b, float a)
 		{
 			X = x; Y = y; Z = z;
 			S = s; T = t;
 			U = u; V = v;
-			C = c;
+			P = p; C = c;
 			R = r; G = g; B = b; A = a;
 		}
 	}
-
-	public sealed class CombinedShaderBindings : ShaderBindings
-	{
-		public CombinedShaderBindings()
-			: base("combined")
-		{ }
-
-		public override ShaderVertexAttribute[] Attributes { get; } = new[]
-		{
-			new ShaderVertexAttribute("aVertexPosition", ShaderVertexAttributeType.Float, 3, 0),
-			new ShaderVertexAttribute("aVertexTexCoord", ShaderVertexAttributeType.Float, 4, 12),
-			new ShaderVertexAttribute("aVertexAttributes", ShaderVertexAttributeType.UInt, 1, 28),
-			new ShaderVertexAttribute("aVertexTint", ShaderVertexAttributeType.Float, 4, 32)
-		};
-	}
 }
--- a/OpenRA.Game/Graphics/Viewport.cs
+++ b/OpenRA.Game/Graphics/Viewport.cs
@@ -53,7 +53,7 @@ namespace OpenRA.Graphics

 		public WPos CenterPosition => worldRenderer.ProjectedPosition(CenterLocation);

-		public Rectangle Rectangle => new(TopLeft, new Size(viewportSize.X, viewportSize.Y));
+		public Rectangle Rectangle => new Rectangle(TopLeft, new Size(viewportSize.X, viewportSize.Y));
 		public int2 TopLeft => CenterLocation - viewportSize / 2;
 		public int2 BottomRight => CenterLocation + viewportSize / 2;
 		int2 viewportSize;
@@ -66,6 +66,9 @@ namespace OpenRA.Graphics
 		WorldViewport lastViewportDistance;

 		float zoom = 1f;
+		float minZoom = 1f;
+		float maxZoom = 2f;
+
 		bool unlockMinZoom;
 		float unlockedMinZoomScale;
 		float unlockedMinZoom = 1f;
@@ -83,13 +86,12 @@ namespace OpenRA.Graphics
 			}
 		}

-		public float MinZoom { get; private set; } = 1f;
-		public float MaxZoom { get; private set; } = 2f;
+		public float MinZoom => minZoom;

 		public void AdjustZoom(float dz)
 		{
 			// Exponential ensures that equal positive and negative steps have the same effect
-			Zoom = (zoom * (float)Math.Exp(dz)).Clamp(unlockMinZoom ? unlockedMinZoom : MinZoom, MaxZoom);
+			Zoom = (zoom * (float)Math.Exp(dz)).Clamp(unlockMinZoom ? unlockedMinZoom : minZoom, maxZoom);
 		}

 		public void AdjustZoom(float dz, int2 center)
@@ -103,10 +105,10 @@ namespace OpenRA.Graphics
 		public void ToggleZoom()
 		{
 			// Unlocked zooms always reset to the default zoom
-			if (zoom < MinZoom)
-				Zoom = MinZoom;
+			if (zoom < minZoom)
+				Zoom = minZoom;
 			else
-				Zoom = zoom > MinZoom ? MinZoom : MaxZoom;
+				Zoom = zoom > minZoom ? minZoom : maxZoom;
 		}

 		public void UnlockMinimumZoom(float scale)
@@ -119,6 +121,23 @@ namespace OpenRA.Graphics
 		public static long LastMoveRunTime = 0;
 		public static int2 LastMousePos;

+		float ClosestTo(float[] collection, float target)
+		{
+			var closestValue = collection.First();
+			var subtractResult = Math.Abs(closestValue - target);
+
+			foreach (var element in collection)
+			{
+				if (Math.Abs(element - target) < subtractResult)
+				{
+					subtractResult = Math.Abs(element - target);
+					closestValue = element;
+				}
+			}
+
+			return closestValue;
+		}
+
 		public ScrollDirection GetBlockedDirections()
 		{
 			var ret = ScrollDirection.None;
@@ -172,7 +191,7 @@ namespace OpenRA.Graphics
 				UpdateViewportZooms();
 		}

-		static float CalculateMinimumZoom(float minHeight, float maxHeight)
+		float CalculateMinimumZoom(float minHeight, float maxHeight)
 		{
 			var h = Game.Renderer.NativeResolution.Height;

@@ -208,14 +227,14 @@ namespace OpenRA.Graphics

 			var vd = graphicSettings.ViewportDistance;
 			if (viewportSizes.AllowNativeZoom && vd == WorldViewport.Native)
-				MinZoom = viewportSizes.DefaultScale;
+				minZoom = viewportSizes.DefaultScale;
 			else
 			{
 				var range = viewportSizes.GetSizeRange(vd);
-				MinZoom = CalculateMinimumZoom(range.X, range.Y) * viewportSizes.DefaultScale;
+				minZoom = CalculateMinimumZoom(range.X, range.Y) * viewportSizes.DefaultScale;
 			}

-			MaxZoom = Math.Min(MinZoom * viewportSizes.MaxZoomScale, Game.Renderer.NativeResolution.Height * viewportSizes.DefaultScale / viewportSizes.MaxZoomWindowHeight);
+			maxZoom = Math.Min(minZoom * viewportSizes.MaxZoomScale, Game.Renderer.NativeResolution.Height * viewportSizes.DefaultScale / viewportSizes.MaxZoomWindowHeight);

 			if (unlockMinZoom)
 			{
@@ -223,19 +242,19 @@ namespace OpenRA.Graphics
 				// TODO: Allow zooming out until the full map is visible
 				// We need to improve our viewport scroll handling to center the map as we zoom out
 				// before this will work well enough to enable
-				unlockedMinZoom = MinZoom * unlockedMinZoomScale;
+				unlockedMinZoom = minZoom * unlockedMinZoomScale;
 			}

 			if (resetCurrentZoom)
-				Zoom = MinZoom;
+				Zoom = minZoom;
 			else
-				Zoom = Zoom.Clamp(MinZoom, MaxZoom);
+				Zoom = Zoom.Clamp(minZoom, maxZoom);

-			var maxSize = 1f / (unlockMinZoom ? unlockedMinZoom : MinZoom) * new float2(Game.Renderer.NativeResolution);
+			var maxSize = (1f / (unlockMinZoom ? unlockedMinZoom : minZoom) * new float2(Game.Renderer.NativeResolution));
 			Game.Renderer.SetMaximumViewportSize(new Size((int)maxSize.X, (int)maxSize.Y));

 			foreach (var t in worldRenderer.World.WorldActor.TraitsImplementing<INotifyViewportZoomExtentsChanged>())
-				t.ViewportZoomExtentsChanged(MinZoom, MaxZoom);
+				t.ViewportZoomExtentsChanged(minZoom, maxZoom);
 		}

 		public CPos ViewToWorld(int2 view)
@@ -278,27 +297,15 @@ namespace OpenRA.Graphics
 			return worldRenderer.World.Map.CellContaining(worldRenderer.ProjectedPosition(ViewToWorldPx(view)));
 		}

-		/// <summary>Returns an unfiltered list of all cells that could potentially contain the mouse cursor.</summary>
+		/// <summary> Returns an unfiltered list of all cells that could potentially contain the mouse cursor</summary>
 		IEnumerable<MPos> CandidateMouseoverCells(int2 world)
 		{
 			var map = worldRenderer.World.Map;
-			var tileScale = map.Grid.TileScale / 2;
 			var minPos = worldRenderer.ProjectedPosition(world);

-			// Find all the cells that could potentially have been clicked.
-			MPos a;
-			MPos b;
-			if (map.Grid.Type == MapGridType.RectangularIsometric)
-			{
-				// TODO: this generates too many cells.
-				a = map.CellContaining(minPos - new WVec(tileScale, 0, 0)).ToMPos(map.Grid.Type);
-				b = map.CellContaining(minPos + new WVec(tileScale, tileScale * map.Grid.MaximumTerrainHeight, 0)).ToMPos(map.Grid.Type);
-			}
-			else
-			{
-				a = map.CellContaining(minPos).ToMPos(map.Grid.Type);
-				b = map.CellContaining(minPos + new WVec(0, tileScale * map.Grid.MaximumTerrainHeight, 0)).ToMPos(map.Grid.Type);
-			}
+			// Find all the cells that could potentially have been clicked
+			var a = map.CellContaining(minPos - new WVec(1024, 0, 0)).ToMPos(map.Grid.Type);
+			var b = map.CellContaining(minPos + new WVec(512, 512 * map.Grid.MaximumTerrainHeight, 0)).ToMPos(map.Grid.Type);

 			for (var v = b.V; v >= a.V; v--)
 				for (var u = b.U; u >= a.U; u--)
@@ -306,18 +313,15 @@ namespace OpenRA.Graphics
 		}

 		public int2 ViewToWorldPx(int2 view) { return (graphicSettings.UIScale / Zoom * view.ToFloat2()).ToInt2() + TopLeft; }
-		public int2 WorldToViewPx(int2 world) { return (Zoom / graphicSettings.UIScale * (world - TopLeft).ToFloat2()).ToInt2(); }
-		public int2 WorldToViewPx(in float3 world) { return (Zoom / graphicSettings.UIScale * (world - TopLeft).XY).ToInt2(); }
+		public int2 WorldToViewPx(int2 world) { return ((Zoom / graphicSettings.UIScale) * (world - TopLeft).ToFloat2()).ToInt2(); }
+		public int2 WorldToViewPx(in float3 world) { return ((Zoom / graphicSettings.UIScale) * (world - TopLeft).XY).ToInt2(); }

 		public void Center(IEnumerable<Actor> actors)
 		{
-			var actorsCollection = actors as IReadOnlyCollection<Actor>;
-			actorsCollection ??= actors.ToList();
-
-			if (actorsCollection.Count == 0)
+			if (!actors.Any())
 				return;

-			Center(actorsCollection.Select(a => a.CenterPosition).Average());
+			Center(actors.Select(a => a.CenterPosition).Average());
 		}

 		public void Center(WPos pos)
--- a/OpenRA.Game/Graphics/WorldRenderer.cs
+++ b/OpenRA.Game/Graphics/WorldRenderer.cs
@@ -31,27 +31,25 @@ namespace OpenRA.Graphics

 		public event Action PaletteInvalidated = null;

-		readonly HashSet<Actor> onScreenActors = new();
-		readonly HardwarePalette palette = new();
-		readonly Dictionary<string, PaletteReference> palettes = new();
+		readonly HashSet<Actor> onScreenActors = new HashSet<Actor>();
+		readonly HardwarePalette palette = new HardwarePalette();
+		readonly Dictionary<string, PaletteReference> palettes = new Dictionary<string, PaletteReference>();
 		readonly IRenderTerrain terrainRenderer;
 		readonly Lazy<DebugVisualizations> debugVis;
 		readonly Func<string, PaletteReference> createPaletteReference;
 		readonly bool enableDepthBuffer;

-		readonly List<IFinalizedRenderable> preparedRenderables = new();
-		readonly List<IFinalizedRenderable> preparedOverlayRenderables = new();
-		readonly List<IFinalizedRenderable> preparedAnnotationRenderables = new();
+		readonly List<IFinalizedRenderable> preparedRenderables = new List<IFinalizedRenderable>();
+		readonly List<IFinalizedRenderable> preparedOverlayRenderables = new List<IFinalizedRenderable>();
+		readonly List<IFinalizedRenderable> preparedAnnotationRenderables = new List<IFinalizedRenderable>();

-		readonly List<IRenderable> renderablesBuffer = new();
-		readonly IRenderer[] renderers;
-		readonly IRenderPostProcessPass[] postProcessPasses;
+		readonly List<IRenderable> renderablesBuffer = new List<IRenderable>();

 		internal WorldRenderer(ModData modData, World world)
 		{
 			World = world;
 			TileSize = World.Map.Grid.TileSize;
-			TileScale = World.Map.Grid.TileScale;
+			TileScale = World.Map.Grid.Type == MapGridType.RectangularIsometric ? 1448 : 1024;
 			Viewport = new Viewport(this, world.Map);

 			createPaletteReference = CreatePaletteReference;
@@ -68,24 +66,9 @@ namespace OpenRA.Graphics
 			palette.Initialize();

 			TerrainLighting = world.WorldActor.TraitOrDefault<ITerrainLighting>();
-			renderers = world.WorldActor.TraitsImplementing<IRenderer>().ToArray();
 			terrainRenderer = world.WorldActor.TraitOrDefault<IRenderTerrain>();

 			debugVis = Exts.Lazy(() => world.WorldActor.TraitOrDefault<DebugVisualizations>());
-
-			postProcessPasses = world.WorldActor.TraitsImplementing<IRenderPostProcessPass>().ToArray();
-		}
-
-		public void BeginFrame()
-		{
-			foreach (var r in renderers)
-				r.BeginFrame();
-		}
-
-		public void EndFrame()
-		{
-			foreach (var r in renderers)
-				r.EndFrame();
 		}

 		public void UpdatePalettesForPlayer(string internalName, Color color, bool replaceExisting)
@@ -104,7 +87,7 @@ namespace OpenRA.Graphics
 		{
 			// HACK: This is working around the fact that palettes are defined on traits rather than sequences
 			// and can be removed once this has been fixed.
-			return string.IsNullOrEmpty(name) ? null : palettes.GetOrAdd(name, createPaletteReference);
+			return name == null ? null : palettes.GetOrAdd(name, createPaletteReference);
 		}

 		public void AddPalette(string name, ImmutablePalette pal, bool allowModifiers = false, bool allowOverwrite = false)
@@ -126,13 +109,13 @@ namespace OpenRA.Graphics
 			palette.ReplacePalette(name, pal);

 			// Update cached PlayerReference if one exists
-			if (palettes.TryGetValue(name, out var paletteReference))
-				paletteReference.Palette = pal;
+			if (palettes.ContainsKey(name))
+				palettes[name].Palette = pal;
 		}

-		public void SetPaletteColorShift(string name, float hueOffset, float satOffset, float valueModifier, float minHue, float maxHue)
+		public void SetPaletteColorShift(string name, float hueOffset, float satOffset, float minHue, float maxHue)
 		{
-			palette.SetColorShift(name, hueOffset, satOffset, valueModifier, minHue, maxHue);
+			palette.SetColorShift(name, hueOffset, satOffset, minHue, maxHue);
 		}

 		// PERF: Avoid LINQ.
@@ -194,7 +177,7 @@ namespace OpenRA.Graphics

 			foreach (var e in World.Effects)
 			{
-				if (e is not IEffectAboveShroud ea)
+				if (!(e is IEffectAboveShroud ea))
 					continue;

 				foreach (var renderable in ea.RenderAboveShroud(this))
@@ -235,7 +218,7 @@ namespace OpenRA.Graphics

 			foreach (var e in World.Effects)
 			{
-				if (e is not IEffectAnnotation ea)
+				if (!(e is IEffectAnnotation ea))
 					continue;

 				foreach (var renderAnnotation in ea.RenderAnnotation(this))
@@ -287,8 +270,6 @@ namespace OpenRA.Graphics
 			if (enableDepthBuffer)
 				Game.Renderer.ClearDepthBuffer();

-			ApplyPostProcessing(PostProcessPassType.AfterActors);
-
 			World.ApplyToActorsWithTrait<IRenderAboveWorld>((actor, trait) =>
 			{
 				if (actor.IsInWorld && !actor.Disposed)
@@ -298,8 +279,6 @@ namespace OpenRA.Graphics
 			if (enableDepthBuffer)
 				Game.Renderer.ClearDepthBuffer();

-			ApplyPostProcessing(PostProcessPassType.AfterWorld);
-
 			World.ApplyToActorsWithTrait<IRenderShroud>((actor, trait) => trait.RenderShroud(this));

 			if (enableDepthBuffer)
@@ -313,23 +292,9 @@ namespace OpenRA.Graphics
 				foreach (var r in g)
 					r.Render(this);

-			ApplyPostProcessing(PostProcessPassType.AfterShroud);
-
 			Game.Renderer.Flush();
 		}

-		void ApplyPostProcessing(PostProcessPassType type)
-		{
-			foreach (var pass in postProcessPasses)
-			{
-				if (pass.Type != type || !pass.Enabled)
-					continue;
-
-				Game.Renderer.Flush();
-				pass.Draw(this);
-			}
-		}
-
 		public void DrawAnnotations()
 		{
 			Game.Renderer.EnableAntialiasingFilter();
--- a/OpenRA.Game/HotkeyDefinition.cs
+++ b/OpenRA.Game/HotkeyDefinition.cs
@@ -10,6 +10,7 @@
 #endregion

 using System.Collections.Generic;
+using System.Linq;

 namespace OpenRA
 {
@@ -18,8 +19,8 @@ namespace OpenRA
 		public readonly string Name;
 		public readonly Hotkey Default = Hotkey.Invalid;
 		public readonly string Description = "";
-		public readonly HashSet<string> Types = new();
-		public readonly HashSet<string> Contexts = new();
+		public readonly HashSet<string> Types = new HashSet<string>();
+		public readonly HashSet<string> Contexts = new HashSet<string>();
 		public readonly bool Readonly = false;
 		public bool HasDuplicates { get; internal set; }

@@ -30,26 +31,29 @@ namespace OpenRA
 			if (!string.IsNullOrEmpty(node.Value))
 				Default = FieldLoader.GetValue<Hotkey>("value", node.Value);

-			var nodeDict = node.ToDictionary();
+			var descriptionNode = node.Nodes.FirstOrDefault(n => n.Key == "Description");
+			if (descriptionNode != null)
+				Description = descriptionNode.Value.Value;

-			if (nodeDict.TryGetValue("Description", out var descriptionYaml))
-				Description = descriptionYaml.Value;
+			var typesNode = node.Nodes.FirstOrDefault(n => n.Key == "Types");
+			if (typesNode != null)
+				Types = FieldLoader.GetValue<HashSet<string>>("Types", typesNode.Value.Value);

-			if (nodeDict.TryGetValue("Types", out var typesYaml))
-				Types = FieldLoader.GetValue<HashSet<string>>("Types", typesYaml.Value);
+			var contextsNode = node.Nodes.FirstOrDefault(n => n.Key == "Contexts");
+			if (contextsNode != null)
+				Contexts = FieldLoader.GetValue<HashSet<string>>("Contexts", contextsNode.Value.Value);

-			if (nodeDict.TryGetValue("Contexts", out var contextYaml))
-				Contexts = FieldLoader.GetValue<HashSet<string>>("Contexts", contextYaml.Value);
-
-			if (nodeDict.TryGetValue("Platform", out var platformYaml))
+			var platformNode = node.Nodes.FirstOrDefault(n => n.Key == "Platform");
+			if (platformNode != null)
 			{
-				var platformOverride = platformYaml.NodeWithKeyOrDefault(Platform.CurrentPlatform.ToString());
+				var platformOverride = platformNode.Value.Nodes.FirstOrDefault(n => n.Key == Platform.CurrentPlatform.ToString());
 				if (platformOverride != null)
 					Default = FieldLoader.GetValue<Hotkey>("value", platformOverride.Value.Value);
 			}

-			if (nodeDict.TryGetValue("Readonly", out var readonlyYaml))
-				Readonly = FieldLoader.GetValue<bool>("Readonly", readonlyYaml.Value);
+			var readonlyNode = node.Nodes.FirstOrDefault(n => n.Key == "Readonly");
+			if (readonlyNode != null)
+				Readonly = FieldLoader.GetValue<bool>("Readonly", readonlyNode.Value.Value);
 		}
 	}
 }
--- a/OpenRA.Game/HotkeyManager.cs
+++ b/OpenRA.Game/HotkeyManager.cs
@@ -18,8 +18,8 @@ namespace OpenRA
 	public sealed class HotkeyManager
 	{
 		readonly Dictionary<string, Hotkey> settings;
-		readonly Dictionary<string, HotkeyDefinition> definitions = new();
-		readonly Dictionary<string, Hotkey> keys = new();
+		readonly Dictionary<string, HotkeyDefinition> definitions = new Dictionary<string, HotkeyDefinition>();
+		readonly Dictionary<string, Hotkey> keys = new Dictionary<string, Hotkey>();

 		public HotkeyManager(IReadOnlyFileSystem fileSystem, Dictionary<string, Hotkey> settings, Manifest manifest)
 		{
@@ -35,7 +35,7 @@ namespace OpenRA

 			foreach (var kv in settings)
 			{
-				if (definitions.TryGetValue(kv.Key, out var definition) && !definition.Readonly)
+				if (definitions.ContainsKey(kv.Key) && !definitions[kv.Key].Readonly)
 					keys[kv.Key] = kv.Value;
 			}

@@ -43,9 +43,6 @@ namespace OpenRA
 				hd.Value.HasDuplicates = GetFirstDuplicate(hd.Value, this[hd.Value.Name].GetValue()) != null;
 		}

-		[System.Diagnostics.CodeAnalysis.SuppressMessage(
-			"Performance", "CA1854:Prefer the 'IDictionary.TryGetValue(TKey, out TValue)' method",
-			Justification = "Func must perform a live lookup in the collection, as the lookup value can change.")]
 		internal Func<Hotkey> GetHotkeyReference(string name)
 		{
 			// Is this a mod-defined hotkey?
@@ -105,7 +102,7 @@ namespace OpenRA
 			return null;
 		}

-		public HotkeyReference this[string name] => new(GetHotkeyReference(name));
+		public HotkeyReference this[string name] => new HotkeyReference(GetHotkeyReference(name));

 		public IEnumerable<HotkeyDefinition> Definitions => definitions.Values;
 	}
--- a/OpenRA.Game/IUtilityCommand.cs
+++ b/OpenRA.Game/IUtilityCommand.cs
@@ -9,41 +9,12 @@
 */
 #endregion

-using System;
-using System.Reflection;
-using OpenRA.Primitives;
 using OpenRA.Traits;

 namespace OpenRA
 {
 	public class Utility
 	{
-		static readonly ConcurrentCache<Type, FieldInfo[]> TypeFields =
-			new(type => type.GetFields());
-
-		static readonly ConcurrentCache<(MemberInfo Member, Type AttributeType), bool> MemberHasAttribute =
-			new(x => Attribute.IsDefined(x.Member, x.AttributeType));
-
-		static readonly ConcurrentCache<(MemberInfo Member, Type AttributeType, bool Inherit), object[]> MemberCustomAttributes =
-			new(x => x.Member.GetCustomAttributes(x.AttributeType, x.Inherit));
-
-		public static FieldInfo[] GetFields(Type type)
-		{
-			return TypeFields[type];
-		}
-
-		public static bool HasAttribute<TAttribute>(MemberInfo member)
-			where TAttribute : Attribute
-		{
-			return MemberHasAttribute[(member, typeof(TAttribute))];
-		}
-
-		public static TAttribute[] GetCustomAttributes<TAttribute>(MemberInfo member, bool inherit)
-			where TAttribute : Attribute
-		{
-			return (TAttribute[])MemberCustomAttributes[(member, typeof(TAttribute), inherit)];
-		}
-
 		public readonly ModData ModData;
 		public readonly InstalledMods Mods;

--- a/OpenRA.Game/Input/Hotkey.cs
+++ b/OpenRA.Game/Input/Hotkey.cs
@@ -15,7 +15,7 @@ namespace OpenRA
 {
 	public readonly struct Hotkey : IEquatable<Hotkey>
 	{
-		public static Hotkey Invalid = new(Keycode.UNKNOWN, Modifiers.None);
+		public static Hotkey Invalid = new Hotkey(Keycode.UNKNOWN, Modifiers.None);
 		public bool IsValid()
 		{
 			return Key != Keycode.UNKNOWN;
@@ -42,7 +42,7 @@ namespace OpenRA
 			var mods = Modifiers.None;
 			if (parts.Length >= 2)
 			{
-				var modString = s[s.IndexOf(' ')..];
+				var modString = s.Substring(s.IndexOf(' '));
 				if (!Enum<Modifiers>.TryParse(modString, true, out mods))
 					return false;
 			}
@@ -84,7 +84,7 @@ namespace OpenRA
 			return obj is Hotkey o && (Hotkey?)o == this;
 		}

-		public override string ToString() { return $"{Key} {Modifiers:F}"; }
+		public override string ToString() { return $"{Key} {Modifiers.ToString("F")}"; }

 		public string DisplayString()
 		{
--- a/OpenRA.Game/Input/HotkeyReference.cs
+++ b/OpenRA.Game/Input/HotkeyReference.cs
@@ -14,7 +14,7 @@ using System;
 namespace OpenRA
 {
 	/// <summary>
-	/// A reference to either a named hotkey (defined in the game settings) or a statically assigned hotkey.
+	/// A reference to either a named hotkey (defined in the game settings) or a statically assigned hotkey
 	/// </summary>
 	public class HotkeyReference
 	{
--- a/OpenRA.Game/Input/Keycode.cs
+++ b/OpenRA.Game/Input/Keycode.cs
@@ -13,8 +13,7 @@ using System.Collections.Generic;

 namespace OpenRA
 {
-	// List of keycodes. Duplicated from SDL 2.0.1, with the addition
-	// of MOUSE4 and MOUSE5.
+	// List of keycodes, duplicated from SDL 2.0.1
 	public enum Keycode
 	{
 		UNKNOWN = 0,
@@ -253,13 +252,11 @@ namespace OpenRA
 		KBDILLUMUP = 280 | (1 << 30),
 		EJECT = 281 | (1 << 30),
 		SLEEP = 282 | (1 << 30),
-		MOUSE4 = 283 | (1 << 30),
-		MOUSE5 = 284 | (1 << 30)
 	}

 	public static class KeycodeExts
 	{
-		static readonly Dictionary<Keycode, string> KeyNames = new()
+		static readonly Dictionary<Keycode, string> KeyNames = new Dictionary<Keycode, string>
 		{
 			{ Keycode.UNKNOWN, "Undefined" },
 			{ Keycode.RETURN, "Return" },
@@ -497,8 +494,6 @@ namespace OpenRA
 			{ Keycode.KBDILLUMUP, "KBDIllumUp" },
 			{ Keycode.EJECT, "Eject" },
 			{ Keycode.SLEEP, "Sleep" },
-			{ Keycode.MOUSE4, "Mouse 4" },
-			{ Keycode.MOUSE5, "Mouse 5" },
 		};

 		public static string DisplayString(Keycode k)
--- a/OpenRA.Game/InstalledMods.cs
+++ b/OpenRA.Game/InstalledMods.cs
@@ -54,7 +54,7 @@ namespace OpenRA
 			return mods;
 		}

-		static Manifest LoadMod(string id, string path)
+		Manifest LoadMod(string id, string path)
 		{
 			IReadOnlyPackage package = null;
 			try
@@ -79,7 +79,7 @@ namespace OpenRA
 			return null;
 		}

-		static Dictionary<string, Manifest> GetInstalledMods(IEnumerable<string> searchPaths, IEnumerable<string> explicitPaths)
+		Dictionary<string, Manifest> GetInstalledMods(IEnumerable<string> searchPaths, IEnumerable<string> explicitPaths)
 		{
 			var ret = new Dictionary<string, Manifest>();
 			var candidates = GetCandidateMods(searchPaths)
--- a/OpenRA.Game/LocalPlayerProfile.cs
+++ b/OpenRA.Game/LocalPlayerProfile.cs
@@ -66,10 +66,8 @@ namespace OpenRA
 			}
 			catch (Exception e)
 			{
-				Console.WriteLine("Failed to load keys:");
-				Console.WriteLine(e);
-				Log.Write("debug", $"Failed to load player keypair from `{filePath}` with exception:");
-				Log.Write("debug", e);
+				Console.WriteLine("Failed to load keys: {0}", e);
+				Log.Write("debug", "Failed to load player keypair from `{0}` with exception: {1}", filePath, e);
 			}
 		}

@@ -84,17 +82,16 @@ namespace OpenRA
 				{
 					var client = HttpClientFactory.Create();

-					var url = playerDatabase.Profile + Fingerprint;
-					var httpResponseMessage = await client.GetAsync(url);
+					var httpResponseMessage = await client.GetAsync(playerDatabase.Profile + Fingerprint);
 					var result = await httpResponseMessage.Content.ReadAsStreamAsync();

-					var yaml = MiniYaml.FromStream(result, url).First();
+					var yaml = MiniYaml.FromStream(result).First();
 					if (yaml.Key == "Player")
 					{
 						innerData = FieldLoader.Load<PlayerProfile>(yaml.Value);
 						if (innerData.KeyRevoked)
 						{
-							Log.Write("debug", $"Revoking key with fingerprint {Fingerprint}");
+							Log.Write("debug", "Revoking key with fingerprint {0}", Fingerprint);
 							DeleteKeypair();
 						}
 						else
@@ -105,8 +102,7 @@ namespace OpenRA
 				}
 				catch (Exception e)
 				{
-					Log.Write("debug", "Failed to parse player data result with exception:");
-					Log.Write("debug", e);
+					Log.Write("debug", "Failed to parse player data result with exception: {0}", e);
 					innerState = LinkState.ConnectionFailed;
 				}
 				finally
@@ -140,10 +136,8 @@ namespace OpenRA
 				}
 				catch (Exception e)
 				{
-					Log.Write("debug", "Failed to generate keypair with exception:");
-					Log.Write("debug", e);
-					Console.WriteLine("Key generation failed:");
-					Console.WriteLine(e);
+					Log.Write("debug", "Failed to generate keypair with exception: {1}", e);
+					Console.WriteLine("Key generation failed: {0}", e);

 					innerState = LinkState.Uninitialized;
 				}
@@ -158,10 +152,8 @@ namespace OpenRA
 			}
 			catch (Exception e)
 			{
-				Log.Write("debug", "Failed to delete keypair with exception:");
-				Log.Write("debug", e);
-				Console.WriteLine("Key deletion failed:");
-				Console.WriteLine(e);
+				Log.Write("debug", "Failed to delete keypair with exception: {1}", e);
+				Console.WriteLine("Key deletion failed: {0}", e);
 			}

 			innerState = LinkState.Uninitialized;
--- a/OpenRA.Game/LogProxy.cs
+++ b/OpenRA.Game/LogProxy.cs
@@ -0,0 +1,26 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+namespace OpenRA
+{
+	public interface ILog
+	{
+		void Write(string channel, string format, params object[] args);
+	}
+
+	public class LogProxy : ILog
+	{
+		public void Write(string channel, string format, params object[] args)
+		{
+			Log.Write(channel, format, args);
+		}
+	}
+}
--- a/OpenRA.Game/MPos.cs
+++ b/OpenRA.Game/MPos.cs
@@ -19,7 +19,7 @@ namespace OpenRA
 		public readonly int U, V;

 		public MPos(int u, int v) { U = u; V = v; }
-		public static readonly MPos Zero = new(0, 0);
+		public static readonly MPos Zero = new MPos(0, 0);

 		public static bool operator ==(MPos me, MPos other) { return me.U == other.U && me.V == other.V; }
 		public static bool operator !=(MPos me, MPos other) { return !(me == other); }
@@ -27,7 +27,7 @@ namespace OpenRA
 		public override int GetHashCode() { return U.GetHashCode() ^ V.GetHashCode(); }

 		public bool Equals(MPos other) { return other == this; }
-		public override bool Equals(object obj) { return obj is MPos uv && Equals(uv); }
+		public override bool Equals(object obj) { return obj is MPos && Equals((MPos)obj); }

 		public MPos Clamp(Rectangle r)
 		{
@@ -64,14 +64,14 @@ namespace OpenRA
 	}

 	/// <summary>
-	/// Projected map position.
+	/// Projected map position
 	/// </summary>
 	public readonly struct PPos : IEquatable<PPos>
 	{
 		public readonly int U, V;

 		public PPos(int u, int v) { U = u; V = v; }
-		public static readonly PPos Zero = new(0, 0);
+		public static readonly PPos Zero = new PPos(0, 0);

 		public static bool operator ==(PPos me, PPos other) { return me.U == other.U && me.V == other.V; }
 		public static bool operator !=(PPos me, PPos other) { return !(me == other); }
@@ -88,7 +88,7 @@ namespace OpenRA
 		public override int GetHashCode() { return U.GetHashCode() ^ V.GetHashCode(); }

 		public bool Equals(PPos other) { return other == this; }
-		public override bool Equals(object obj) { return obj is PPos puv && Equals(puv); }
+		public override bool Equals(object obj) { return obj is PPos && Equals((PPos)obj); }

 		public override string ToString() { return U + "," + V; }
 	}
--- a/OpenRA.Game/Manifest.cs
+++ b/OpenRA.Game/Manifest.cs
@@ -43,6 +43,17 @@ namespace OpenRA
 		}
 	}

+	public sealed class ModelSequenceFormat : IGlobalModData
+	{
+		public readonly string Type;
+		public readonly IReadOnlyDictionary<string, MiniYaml> Metadata;
+		public ModelSequenceFormat(MiniYaml yaml)
+		{
+			Type = yaml.Value;
+			Metadata = new ReadOnlyDictionary<string, MiniYaml>(yaml.ToDictionary());
+		}
+	}
+
 	public class ModMetadata
 	{
 		public string Title;
@@ -53,8 +64,8 @@ namespace OpenRA
 		public bool Hidden;
 	}

-	/// <summary>Describes what is to be loaded in order to run a mod.</summary>
-	public sealed class Manifest : IDisposable
+	/// <summary> Describes what is to be loaded in order to run a mod. </summary>
+	public class Manifest : IDisposable
 	{
 		public readonly string Id;
 		public readonly IReadOnlyPackage Package;
@@ -84,7 +95,7 @@ namespace OpenRA
 			"RequiresMods", "PackageFormats"
 		};

-		readonly TypeDictionary modules = new();
+		readonly TypeDictionary modules = new TypeDictionary();
 		readonly Dictionary<string, MiniYaml> yaml;

 		bool customDataLoaded;
@@ -94,8 +105,7 @@ namespace OpenRA
 			Id = modId;
 			Package = package;

-			var stringPool = new HashSet<string>(); // Reuse common strings in YAML
-			var nodes = MiniYaml.FromStream(package.GetStream("mod.yaml"), $"{package.Name}:mod.yaml", stringPool: stringPool);
+			var nodes = MiniYaml.FromStream(package.GetStream("mod.yaml"), "mod.yaml");
 			for (var i = nodes.Count - 1; i >= 0; i--)
 			{
 				if (nodes[i].Key != "Include")
@@ -108,7 +118,7 @@ namespace OpenRA
 					throw new YamlException($"{nodes[i].Location}: File `{filename}` not found.");

 				nodes.RemoveAt(i);
-				nodes.InsertRange(i, MiniYaml.FromStream(contents, $"{package.Name}:{filename}", stringPool: stringPool));
+				nodes.InsertRange(i, MiniYaml.FromStream(contents, filename));
 			}

 			// Merge inherited overrides
@@ -147,25 +157,25 @@ namespace OpenRA
 			// Allow inherited mods to import parent maps.
 			var compat = new List<string> { Id };

-			if (yaml.TryGetValue("SupportsMapsFrom", out var entry))
-				compat.AddRange(entry.Value.Split(',').Select(c => c.Trim()));
+			if (yaml.ContainsKey("SupportsMapsFrom"))
+				compat.AddRange(yaml["SupportsMapsFrom"].Value.Split(',').Select(c => c.Trim()));

 			MapCompatibility = compat.ToArray();

-			if (yaml.TryGetValue("DefaultOrderGenerator", out entry))
-				DefaultOrderGenerator = entry.Value;
+			if (yaml.ContainsKey("DefaultOrderGenerator"))
+				DefaultOrderGenerator = yaml["DefaultOrderGenerator"].Value;

-			if (yaml.TryGetValue("PackageFormats", out entry))
-				PackageFormats = FieldLoader.GetValue<string[]>("PackageFormats", entry.Value);
+			if (yaml.ContainsKey("PackageFormats"))
+				PackageFormats = FieldLoader.GetValue<string[]>("PackageFormats", yaml["PackageFormats"].Value);

-			if (yaml.TryGetValue("SoundFormats", out entry))
-				SoundFormats = FieldLoader.GetValue<string[]>("SoundFormats", entry.Value);
+			if (yaml.ContainsKey("SoundFormats"))
+				SoundFormats = FieldLoader.GetValue<string[]>("SoundFormats", yaml["SoundFormats"].Value);

-			if (yaml.TryGetValue("SpriteFormats", out entry))
-				SpriteFormats = FieldLoader.GetValue<string[]>("SpriteFormats", entry.Value);
+			if (yaml.ContainsKey("SpriteFormats"))
+				SpriteFormats = FieldLoader.GetValue<string[]>("SpriteFormats", yaml["SpriteFormats"].Value);

-			if (yaml.TryGetValue("VideoFormats", out entry))
-				VideoFormats = FieldLoader.GetValue<string[]>("VideoFormats", entry.Value);
+			if (yaml.ContainsKey("VideoFormats"))
+				VideoFormats = FieldLoader.GetValue<string[]>("VideoFormats", yaml["VideoFormats"].Value);
 		}

 		public void LoadCustomData(ObjectCreator oc)
@@ -201,18 +211,18 @@ namespace OpenRA

 		static string[] YamlList(Dictionary<string, MiniYaml> yaml, string key)
 		{
-			if (!yaml.TryGetValue(key, out var value))
+			if (!yaml.ContainsKey(key))
 				return Array.Empty<string>();

-			return value.Nodes.Select(n => n.Key).ToArray();
+			return yaml[key].ToDictionary().Keys.ToArray();
 		}

 		static IReadOnlyDictionary<string, string> YamlDictionary(Dictionary<string, MiniYaml> yaml, string key)
 		{
-			if (!yaml.TryGetValue(key, out var value))
+			if (!yaml.ContainsKey(key))
 				return new Dictionary<string, string>();

-			return value.ToDictionary(my => my.Value);
+			return yaml[key].ToDictionary(my => my.Value);
 		}

 		public bool Contains<T>() where T : IGlobalModData
--- a/OpenRA.Game/Map/ActorInitializer.cs
+++ b/OpenRA.Game/Map/ActorInitializer.cs
@@ -54,7 +54,7 @@ namespace OpenRA
 			// Traits tagged with an instance name prefer inits with the same name.
 			// If a more specific init is not available, fall back to an unnamed init.
 			// If duplicate inits are defined, take the last to match standard yaml override expectations
-			if (!string.IsNullOrEmpty(info?.InstanceName))
+			if (info != null && !string.IsNullOrEmpty(info.InstanceName))
 				return inits.LastOrDefault(i => i.InstanceName == info.InstanceName) ??
 					inits.LastOrDefault(i => string.IsNullOrEmpty(i.InstanceName));

@@ -159,9 +159,9 @@ namespace OpenRA

 		public virtual void Initialize(T value)
 		{
-			typeof(ValueActorInit<T>)
-				.GetField(nameof(value), BindingFlags.NonPublic | BindingFlags.Instance)
-				?.SetValue(this, value);
+			var field = typeof(ValueActorInit<T>).GetField(nameof(value), BindingFlags.NonPublic | BindingFlags.Instance);
+			if (field != null)
+				field.SetValue(this, value);
 		}

 		public override MiniYaml Save()
@@ -175,7 +175,8 @@ namespace OpenRA
 		protected CompositeActorInit(TraitInfo info)
 			: base(info.InstanceName) { }

-		protected CompositeActorInit() { }
+		protected CompositeActorInit()
+			: base() { }

 		public virtual void Initialize(MiniYaml yaml)
 		{
@@ -245,16 +246,16 @@ namespace OpenRA

 		public void Initialize(MiniYaml yaml)
 		{
-			typeof(OwnerInit)
-				.GetField(nameof(InternalName), BindingFlags.Public | BindingFlags.Instance)
-				?.SetValue(this, yaml.Value);
+			var field = typeof(OwnerInit).GetField(nameof(InternalName), BindingFlags.Public | BindingFlags.Instance);
+			if (field != null)
+				field.SetValue(this, yaml.Value);
 		}

 		public void Initialize(Player player)
 		{
-			typeof(OwnerInit)
-				.GetField(nameof(value), BindingFlags.NonPublic | BindingFlags.Instance)
-				?.SetValue(this, player);
+			var field = typeof(OwnerInit).GetField(nameof(value), BindingFlags.NonPublic | BindingFlags.Instance);
+			if (field != null)
+				field.SetValue(this, player);
 		}

 		public override MiniYaml Save()
--- a/OpenRA.Game/Map/ActorReference.cs
+++ b/OpenRA.Game/Map/ActorReference.cs
@@ -22,7 +22,7 @@ namespace OpenRA
 {
 	public interface ISuppressInitExport { }

-	public class ActorReference : IEnumerable<object>
+	public class ActorReference : IEnumerable
 	{
 		public string Type;
 		readonly Lazy<TypeDictionary> initDict;
@@ -84,29 +84,27 @@ namespace OpenRA

 		public MiniYaml Save(Func<ActorInit, bool> initFilter = null)
 		{
-			var nodes = new List<MiniYamlNode>();
+			var ret = new MiniYaml(Type);
 			foreach (var o in initDict.Value)
 			{
-				if (o is not ActorInit init || o is ISuppressInitExport)
+				if (!(o is ActorInit init) || o is ISuppressInitExport)
 					continue;

 				if (initFilter != null && !initFilter(init))
 					continue;

 				var initTypeName = init.GetType().Name;
-				var initName = initTypeName[..^4];
+				var initName = initTypeName.Substring(0, initTypeName.Length - 4);
 				if (!string.IsNullOrEmpty(init.InstanceName))
 					initName += ActorInfo.TraitInstanceSeparator + init.InstanceName;

-				nodes.Add(new MiniYamlNode(initName, init.Save()));
+				ret.Nodes.Add(new MiniYamlNode(initName, init.Save()));
 			}

-			return new MiniYaml(Type, nodes);
+			return ret;
 		}

-		public IEnumerator<object> GetEnumerator() { return initDict.Value.GetEnumerator(); }
-
-		IEnumerator IEnumerable.GetEnumerator() { return GetEnumerator(); }
+		public IEnumerator GetEnumerator() { return initDict.Value.GetEnumerator(); }

 		public ActorReference Clone()
 		{
@@ -139,7 +137,7 @@ namespace OpenRA
 			return removed;
 		}

-		public IReadOnlyCollection<T> GetAll<T>() where T : ActorInit
+		public IEnumerable<T> GetAll<T>() where T : ActorInit
 		{
 			return initDict.Value.WithInterface<T>();
 		}
@@ -152,9 +150,8 @@ namespace OpenRA
 			// If a more specific init is not available, fall back to an unnamed init.
 			// If duplicate inits are defined, take the last to match standard yaml override expectations
 			if (info != null && !string.IsNullOrEmpty(info.InstanceName))
-				return
-					inits.LastOrDefault(i => i.InstanceName == info.InstanceName) ??
-					inits.LastOrDefault(i => string.IsNullOrEmpty(i.InstanceName));
+				return inits.LastOrDefault(i => i.InstanceName == info.InstanceName) ??
+				       inits.LastOrDefault(i => string.IsNullOrEmpty(i.InstanceName));

 			// Untagged traits will only use untagged inits
 			return inits.LastOrDefault(i => string.IsNullOrEmpty(i.InstanceName));
--- a/OpenRA.Game/Map/CellCoordsRegion.cs
+++ b/OpenRA.Game/Map/CellCoordsRegion.cs
@@ -1,90 +0,0 @@
-#region Copyright & License Information
-/*
- * Copyright (c) The OpenRA Developers and Contributors
- * This file is part of OpenRA, which is free software. It is made
- * available to you under the terms of the GNU General Public License
- * as published by the Free Software Foundation, either version 3 of
- * the License, or (at your option) any later version. For more
- * information, see COPYING.
- */
-#endregion
-
-using System.Collections;
-using System.Collections.Generic;
-
-namespace OpenRA
-{
-	public readonly struct CellCoordsRegion : IEnumerable<CPos>
-	{
-		public struct CellCoordsEnumerator : IEnumerator<CPos>
-		{
-			readonly CellCoordsRegion r;
-
-			public CellCoordsEnumerator(CellCoordsRegion region)
-				: this()
-			{
-				r = region;
-				Reset();
-			}
-
-			public bool MoveNext()
-			{
-				var x = Current.X + 1;
-				var y = Current.Y;
-
-				// Check for column overflow.
-				if (x > r.BottomRight.X)
-				{
-					y++;
-					x = r.TopLeft.X;
-
-					// Check for row overflow.
-					if (y > r.BottomRight.Y)
-						return false;
-				}
-
-				Current = new CPos(x, y);
-				return true;
-			}
-
-			public void Reset()
-			{
-				Current = new CPos(r.TopLeft.X - 1, r.TopLeft.Y);
-			}
-
-			public CPos Current { get; private set; }
-
-			readonly object IEnumerator.Current => Current;
-			public readonly void Dispose() { }
-		}
-
-		public CellCoordsRegion(CPos topLeft, CPos bottomRight)
-		{
-			TopLeft = topLeft;
-			BottomRight = bottomRight;
-		}
-
-		public override string ToString()
-		{
-			return $"{TopLeft}->{BottomRight}";
-		}
-
-		public CellCoordsEnumerator GetEnumerator()
-		{
-			return new CellCoordsEnumerator(this);
-		}
-
-		IEnumerator<CPos> IEnumerable<CPos>.GetEnumerator()
-		{
-			return GetEnumerator();
-		}
-
-		IEnumerator IEnumerable.GetEnumerator()
-		{
-			return GetEnumerator();
-		}
-
-		public CPos TopLeft { get; }
-		public CPos BottomRight { get; }
-	}
-}
--- a/OpenRA.Game/Map/CellLayer.cs
+++ b/OpenRA.Game/Map/CellLayer.cs
@@ -72,7 +72,7 @@ namespace OpenRA
 			return uv.V * Size.Width + uv.U;
 		}

-		/// <summary>Gets or sets the <see cref="CellLayer"/> using cell coordinates.</summary>
+		/// <summary>Gets or sets the <see cref="CellLayer"/> using cell coordinates</summary>
 		public T this[CPos cell]
 		{
 			get => Entries[Index(cell)];
@@ -85,7 +85,7 @@ namespace OpenRA
 			}
 		}

-		/// <summary>Gets or sets the layer contents using raw map coordinates (not CPos!).</summary>
+		/// <summary>Gets or sets the layer contents using raw map coordinates (not CPos!)</summary>
 		public T this[MPos uv]
 		{
 			get => Entries[Index(uv)];
--- a/OpenRA.Game/Map/CellLayerBase.cs
+++ b/OpenRA.Game/Map/CellLayerBase.cs
@@ -24,10 +24,10 @@ namespace OpenRA
 		protected readonly T[] Entries;
 		protected readonly Rectangle Bounds;

-		protected CellLayerBase(Map map)
+		public CellLayerBase(Map map)
 			: this(map.Grid.Type, new Size(map.MapSize.X, map.MapSize.Y)) { }

-		protected CellLayerBase(MapGridType gridType, Size size)
+		public CellLayerBase(MapGridType gridType, Size size)
 		{
 			Size = size;
 			Bounds = new Rectangle(0, 0, Size.Width, Size.Height);
@@ -43,13 +43,13 @@ namespace OpenRA
 			Array.Copy(anotherLayer.Entries, Entries, Entries.Length);
 		}

-		/// <summary>Clears the layer contents with their default value.</summary>
+		/// <summary>Clears the layer contents with their default value</summary>
 		public virtual void Clear()
 		{
 			Array.Clear(Entries, 0, Entries.Length);
 		}

-		/// <summary>Clears the layer contents with a known value.</summary>
+		/// <summary>Clears the layer contents with a known value</summary>
 		public virtual void Clear(T clearValue)
 		{
 			Array.Fill(Entries, clearValue);
--- a/OpenRA.Game/Map/CellRegion.cs
+++ b/OpenRA.Game/Map/CellRegion.cs
@@ -12,6 +12,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Linq;

 namespace OpenRA
 {
@@ -63,9 +64,9 @@ namespace OpenRA
 		}

 		/// <summary>Returns the minimal region that covers at least the specified cells.</summary>
-		public static CellRegion BoundingRegion(MapGridType shape, IReadOnlyCollection<CPos> cells)
+		public static CellRegion BoundingRegion(MapGridType shape, IEnumerable<CPos> cells)
 		{
-			if (cells == null || cells.Count == 0)
+			if (cells == null || !cells.Any())
 				throw new ArgumentException("cells must not be null or empty.", nameof(cells));

 			var minU = int.MaxValue;
@@ -101,8 +102,7 @@ namespace OpenRA
 			return uv.U >= mapTopLeft.U && uv.U <= mapBottomRight.U && uv.V >= mapTopLeft.V && uv.V <= mapBottomRight.V;
 		}

-		public MapCoordsRegion MapCoords => new(mapTopLeft, mapBottomRight);
-		public CellCoordsRegion CellCoords => new(TopLeft, BottomRight);
+		public MapCoordsRegion MapCoords => new MapCoordsRegion(mapTopLeft, mapBottomRight);

 		public CellRegionEnumerator GetEnumerator()
 		{
@@ -126,22 +126,25 @@ namespace OpenRA
 			// Current position, in map coordinates
 			int u, v;

+			// Current position, in cell coordinates
+			CPos current;
+
 			public CellRegionEnumerator(CellRegion region)
 				: this()
 			{
 				r = region;
 				Reset();
-				Current = new MPos(u, v).ToCPos(r.gridType);
+				current = new MPos(u, v).ToCPos(r.gridType);
 			}

 			public bool MoveNext()
 			{
-				u++;
+				u += 1;

 				// Check for column overflow
 				if (u > r.mapBottomRight.U)
 				{
-					v++;
+					v += 1;
 					u = r.mapTopLeft.U;

 					// Check for row overflow
@@ -149,8 +152,7 @@ namespace OpenRA
 						return false;
 				}

-				// Current position, in cell coordinates
-				Current = new MPos(u, v).ToCPos(r.gridType);
+				current = new MPos(u, v).ToCPos(r.gridType);
 				return true;
 			}

@@ -161,9 +163,9 @@ namespace OpenRA
 				v = r.mapTopLeft.V;
 			}

-			public CPos Current { get; private set; }
-			readonly object IEnumerator.Current => Current;
-			public readonly void Dispose() { }
+			public CPos Current => current;
+			object IEnumerator.Current => Current;
+			public void Dispose() { }
 		}
 	}
 }
--- a/OpenRA.Game/Map/Map.cs
+++ b/OpenRA.Game/Map/Map.cs
@@ -11,7 +11,6 @@

 using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.IO;
 using System.Linq;
 using System.Reflection;
@@ -66,7 +65,7 @@ namespace OpenRA
 		MissionSelector = 4
 	}

-	sealed class MapField
+	class MapField
 	{
 		enum Type { Normal, NodeList, MiniYaml }
 		readonly FieldInfo field;
@@ -91,13 +90,13 @@ namespace OpenRA
 				throw new InvalidOperationException("Map does not have a field/property " + fieldName);

 			var t = field != null ? field.FieldType : property.PropertyType;
-			type = t == typeof(IReadOnlyCollection<MiniYamlNode>) ? Type.NodeList :
+			type = t == typeof(List<MiniYamlNode>) ? Type.NodeList :
 				t == typeof(MiniYaml) ? Type.MiniYaml : Type.Normal;
 		}

-		public void Deserialize(Map map, MiniYaml yaml)
+		public void Deserialize(Map map, List<MiniYamlNode> nodes)
 		{
-			var node = yaml.NodeWithKeyOrDefault(key);
+			var node = nodes.FirstOrDefault(n => n.Key == key);
 			if (node == null)
 			{
 				if (required)
@@ -131,14 +130,14 @@ namespace OpenRA
 			var value = field != null ? field.GetValue(map) : property.GetValue(map, null);
 			if (type == Type.NodeList)
 			{
-				var listValue = (IReadOnlyCollection<MiniYamlNode>)value;
+				var listValue = (List<MiniYamlNode>)value;
 				if (required || listValue.Count > 0)
 					nodes.Add(new MiniYamlNode(key, null, listValue));
 			}
 			else if (type == Type.MiniYaml)
 			{
 				var yamlValue = (MiniYaml)value;
-				if (required || (yamlValue != null && (yamlValue.Value != null || yamlValue.Nodes.Length > 0)))
+				if (required || (yamlValue != null && (yamlValue.Value != null || yamlValue.Nodes.Count > 0)))
 					nodes.Add(new MiniYamlNode(key, yamlValue));
 			}
 			else
@@ -150,35 +149,35 @@ namespace OpenRA
 		}
 	}

-	public sealed class Map : IReadOnlyFileSystem, IDisposable
+	public class Map : IReadOnlyFileSystem
 	{
 		public const int SupportedMapFormat = 11;
 		public const int CurrentMapFormat = 12;
 		const short InvalidCachedTerrainIndex = -1;

-		/// <summary>Defines the order of the fields in map.yaml.</summary>
+		/// <summary>Defines the order of the fields in map.yaml</summary>
 		static readonly MapField[] YamlFields =
 		{
-			new("MapFormat"),
-			new("RequiresMod"),
-			new("Title"),
-			new("Author"),
-			new("Tileset"),
-			new("MapSize"),
-			new("Bounds"),
-			new("Visibility"),
-			new("Categories"),
-			new("LockPreview", required: false, ignoreIfValue: "False"),
-			new("Players", "PlayerDefinitions"),
-			new("Actors", "ActorDefinitions"),
-			new("Rules", "RuleDefinitions", required: false),
-			new("Translations", "TranslationDefinitions", required: false),
-			new("Sequences", "SequenceDefinitions", required: false),
-			new("ModelSequences", "ModelSequenceDefinitions", required: false),
-			new("Weapons", "WeaponDefinitions", required: false),
-			new("Voices", "VoiceDefinitions", required: false),
-			new("Music", "MusicDefinitions", required: false),
-			new("Notifications", "NotificationDefinitions", required: false),
+			new MapField("MapFormat"),
+			new MapField("RequiresMod"),
+			new MapField("Title"),
+			new MapField("Author"),
+			new MapField("Tileset"),
+			new MapField("MapSize"),
+			new MapField("Bounds"),
+			new MapField("Visibility"),
+			new MapField("Categories"),
+			new MapField("Translations", required: false, ignoreIfValue: ""),
+			new MapField("LockPreview", required: false, ignoreIfValue: "False"),
+			new MapField("Players", "PlayerDefinitions"),
+			new MapField("Actors", "ActorDefinitions"),
+			new MapField("Rules", "RuleDefinitions", required: false),
+			new MapField("Sequences", "SequenceDefinitions", required: false),
+			new MapField("ModelSequences", "ModelSequenceDefinitions", required: false),
+			new MapField("Weapons", "WeaponDefinitions", required: false),
+			new MapField("Voices", "VoiceDefinitions", required: false),
+			new MapField("Music", "MusicDefinitions", required: false),
+			new MapField("Notifications", "NotificationDefinitions", required: false),
 		};

 		// Format versions
@@ -194,24 +193,24 @@ namespace OpenRA
 		public Rectangle Bounds;
 		public MapVisibility Visibility = MapVisibility.Lobby;
 		public string[] Categories = { "Conquest" };
+		public string[] Translations;

 		public int2 MapSize { get; private set; }

 		// Player and actor yaml. Public for access by the map importers and lint checks.
-		public IReadOnlyCollection<MiniYamlNode> PlayerDefinitions = ImmutableArray<MiniYamlNode>.Empty;
-		public IReadOnlyCollection<MiniYamlNode> ActorDefinitions = ImmutableArray<MiniYamlNode>.Empty;
+		public List<MiniYamlNode> PlayerDefinitions = new List<MiniYamlNode>();
+		public List<MiniYamlNode> ActorDefinitions = new List<MiniYamlNode>();

 		// Custom map yaml. Public for access by the map importers and lint checks
-		public MiniYaml RuleDefinitions;
-		public MiniYaml TranslationDefinitions;
-		public MiniYaml SequenceDefinitions;
-		public MiniYaml ModelSequenceDefinitions;
-		public MiniYaml WeaponDefinitions;
-		public MiniYaml VoiceDefinitions;
-		public MiniYaml MusicDefinitions;
-		public MiniYaml NotificationDefinitions;
+		public readonly MiniYaml RuleDefinitions;
+		public readonly MiniYaml SequenceDefinitions;
+		public readonly MiniYaml ModelSequenceDefinitions;
+		public readonly MiniYaml WeaponDefinitions;
+		public readonly MiniYaml VoiceDefinitions;
+		public readonly MiniYaml MusicDefinitions;
+		public readonly MiniYaml NotificationDefinitions;

-		public readonly Dictionary<CPos, TerrainTile> ReplacedInvalidTerrainTiles = new();
+		public readonly Dictionary<CPos, TerrainTile> ReplacedInvalidTerrainTiles = new Dictionary<CPos, TerrainTile>();

 		// Generated data
 		public readonly MapGrid Grid;
@@ -219,8 +218,6 @@ namespace OpenRA
 		public string Uid { get; private set; }

 		public Ruleset Rules { get; private set; }
-		public SequenceSet Sequences { get; private set; }
-
 		public bool InvalidCustomRules { get; private set; }
 		public Exception InvalidCustomRulesException { get; private set; }

@@ -257,6 +254,8 @@ namespace OpenRA
 		CellLayer<byte> projectedHeight;
 		Rectangle projectionSafeBounds;

+		internal Translation Translation;
+
 		public static string ComputeUID(IReadOnlyPackage package)
 		{
 			return ComputeUID(package, GetMapFormat(package));
@@ -275,10 +274,7 @@ namespace OpenRA
 			try
 			{
 				foreach (var filename in contents)
-					if (filename.EndsWith(".yaml", StringComparison.Ordinal) ||
-						filename.EndsWith(".bin", StringComparison.Ordinal) ||
-						filename.EndsWith(".lua", StringComparison.Ordinal) ||
-						(format >= 12 && filename == "map.png"))
+					if (filename.EndsWith(".yaml") || filename.EndsWith(".bin") || filename.EndsWith(".lua") || (format >= 12 && filename == "map.png"))
 						streams.Add(package.GetStream(filename));

 				// Take the SHA1
@@ -361,15 +357,15 @@ namespace OpenRA
 			if (!Package.Contains("map.yaml") || !Package.Contains("map.bin"))
 				throw new InvalidDataException($"Not a valid map\n File: {package.Name}");

-			var yaml = new MiniYaml(null, MiniYaml.FromStream(Package.GetStream("map.yaml"), $"{package.Name}:map.yaml"));
+			var yaml = new MiniYaml(null, MiniYaml.FromStream(Package.GetStream("map.yaml"), package.Name));
 			foreach (var field in YamlFields)
-				field.Deserialize(this, yaml);
+				field.Deserialize(this, yaml.Nodes);

 			if (MapFormat < SupportedMapFormat)
 				throw new InvalidDataException($"Map format {MapFormat} is not supported.\n File: {package.Name}");

-			PlayerDefinitions = yaml.NodeWithKeyOrDefault("Players")?.Value.Nodes ?? ImmutableArray<MiniYamlNode>.Empty;
-			ActorDefinitions = yaml.NodeWithKeyOrDefault("Actors")?.Value.Nodes ?? ImmutableArray<MiniYamlNode>.Empty;
+			PlayerDefinitions = MiniYaml.NodesOrEmpty(yaml, "Players");
+			ActorDefinitions = MiniYaml.NodesOrEmpty(yaml, "Actors");

 			Grid = modData.Manifest.Get<MapGrid>();

@@ -394,7 +390,7 @@ namespace OpenRA

 							// TODO: Remember to remove this when rewriting tile variants / PickAny
 							if (index == byte.MaxValue)
-								index = (byte)(i % 4 + j % 4 * 4);
+								index = (byte)(i % 4 + (j % 4) * 4);

 							Tiles[new MPos(i, j)] = new TerrainTile(tile, index);
 						}
@@ -441,18 +437,19 @@ namespace OpenRA
 			try
 			{
 				Rules = Ruleset.Load(modData, this, Tileset, RuleDefinitions, WeaponDefinitions,
-					VoiceDefinitions, NotificationDefinitions, MusicDefinitions, ModelSequenceDefinitions);
+					VoiceDefinitions, NotificationDefinitions, MusicDefinitions, SequenceDefinitions, ModelSequenceDefinitions);
 			}
 			catch (Exception e)
 			{
-				Log.Write("debug", $"Failed to load rules for {Title} with error");
-				Log.Write("debug", e);
+				Log.Write("debug", "Failed to load rules for {0} with error {1}", Title, e);
 				InvalidCustomRules = true;
 				InvalidCustomRulesException = e;
 				Rules = Ruleset.LoadDefaultsForTileSet(modData, Tileset);
 			}

-			Sequences = new SequenceSet(this, modData, Tileset, SequenceDefinitions);
+			Rules.Sequences.Preload();
+
+			Translation = new Translation(Game.Settings.Player.Language, Translations, this);

 			var tl = new MPos(0, 0).ToCPos(this);
 			var br = new MPos(MapSize.X - 1, MapSize.Y - 1).ToCPos(this);
@@ -483,17 +480,17 @@ namespace OpenRA
 			AllEdgeCells = UpdateEdgeCells();

 			// Invalidate the entry for a cell if anything could cause the terrain index to change.
-			void InvalidateTerrainIndex(CPos c)
+			Action<CPos> invalidateTerrainIndex = c =>
 			{
 				if (cachedTerrainIndexes != null)
 					cachedTerrainIndexes[c] = InvalidCachedTerrainIndex;
-			}
+			};

 			// Even though the cache is lazily initialized, we must attach these event handlers on init.
 			// This ensures our handler to invalidate the cache runs first,
 			// so other listeners to these same events will get correct data when calling GetTerrainIndex.
-			CustomTerrain.CellEntryChanged += InvalidateTerrainIndex;
-			Tiles.CellEntryChanged += InvalidateTerrainIndex;
+			CustomTerrain.CellEntryChanged += invalidateTerrainIndex;
+			Tiles.CellEntryChanged += invalidateTerrainIndex;
 		}

 		void UpdateRamp(CPos cell)
@@ -611,7 +608,7 @@ namespace OpenRA

 			// Odd-height ramps get bumped up a level to the next even height layer
 			if ((height & 1) == 1 && Ramp[uv] != 0)
-				height++;
+				height += 1;

 			var candidates = new List<PPos>();

@@ -650,25 +647,13 @@ namespace OpenRA
 				foreach (var file in Package.Contents)
 					toPackage.Update(file, Package.GetStream(file).ReadAllBytes());

-			void UpdatePackage(string filename, byte[] data)
-			{
-				if (Package != toPackage)
-					toPackage.Update(filename, data);
-				else
-				{
-					var stream = Package.GetStream(filename);
-					if (stream == null || !Enumerable.SequenceEqual(data, stream.ReadAllBytes()))
-						toPackage.Update(filename, data);
-				}
-			}
-
 			if (!LockPreview)
-				UpdatePackage("map.png", SavePreview());
+				toPackage.Update("map.png", SavePreview());

 			// Update the package with the new map data
-			UpdatePackage("map.yaml", Encoding.UTF8.GetBytes(root.WriteToString()));
-			UpdatePackage("map.bin", SaveBinaryData());
-
+			var s = root.WriteToString();
+			toPackage.Update("map.yaml", Encoding.UTF8.GetBytes(s));
+			toPackage.Update("map.bin", SaveBinaryData());
 			Package = toPackage;

 			// Update UID to match the newly saved data
@@ -688,16 +673,16 @@ namespace OpenRA
 				writer.Write((ushort)MapSize.Y);

 				// Data offsets
-				const int TilesOffset = 17;
+				var tilesOffset = 17;
 				var heightsOffset = Grid.MaximumTerrainHeight > 0 ? 3 * MapSize.X * MapSize.Y + 17 : 0;
 				var resourcesOffset = (Grid.MaximumTerrainHeight > 0 ? 4 : 3) * MapSize.X * MapSize.Y + 17;

-				writer.Write((uint)TilesOffset);
+				writer.Write((uint)tilesOffset);
 				writer.Write((uint)heightsOffset);
 				writer.Write((uint)resourcesOffset);

 				// Tile data
-				if (TilesOffset != 0)
+				if (tilesOffset != 0)
 				{
 					for (var i = 0; i < MapSize.X; i++)
 					{
@@ -754,8 +739,8 @@ namespace OpenRA
 		public byte[] SavePreview()
 		{
 			var actorTypes = Rules.Actors.Values.Where(a => a.HasTraitInfo<IMapPreviewSignatureInfo>());
-			var actors = ActorDefinitions.Where(a => actorTypes.Any(ai => ai.Name == a.Value.Value));
-			var positions = new List<(MPos Uv, Color Color)>();
+			var actors = ActorDefinitions.Where(a => actorTypes.Where(ai => ai.Name == a.Value.Value).Any());
+			var positions = new List<(MPos Position, Color Color)>();
 			foreach (var actor in actors)
 			{
 				var s = new ActorReference(actor.Value.Value, actor.Value.ToDictionary());
@@ -779,10 +764,19 @@ namespace OpenRA

 			if (Grid.MaximumTerrainHeight > 0)
 			{
-				(top, bottom) = GetCellSpaceBounds();
+				// The minimap is drawn in cell space, so we need to
+				// unproject the PPos bounds to find the MPos boundaries.
+				// This matches the calculation in RadarWidget that is used ingame
+				for (var x = Bounds.Left; x < Bounds.Right; x++)
+				{
+					var allTop = Unproject(new PPos(x, Bounds.Top));
+					var allBottom = Unproject(new PPos(x, Bounds.Bottom));
+					if (allTop.Count > 0)
+						top = Math.Min(top, allTop.MinBy(uv => uv.V).V);

-				if (top == int.MaxValue || bottom == int.MinValue)
-					throw new InvalidDataException("The map has invalid boundaries");
+					if (allBottom.Count > 0)
+						bottom = Math.Max(bottom, allBottom.MaxBy(uv => uv.V).V);
+				}
 			}
 			else
 			{
@@ -799,21 +793,18 @@ namespace OpenRA
 				bitmapWidth = 2 * bitmapWidth - 1;

 			var stride = bitmapWidth * 4;
-			const int PxStride = 4;
+			var pxStride = 4;
 			var minimapData = new byte[stride * height];
 			(Color Left, Color Right) terrainColor = default;

-			var colorsByPosition = positions
-				.GroupBy(p => p.Uv)
-				.ToDictionary(g => g.Key, g => g.First().Color);
 			for (var y = 0; y < height; y++)
 			{
 				for (var x = 0; x < width; x++)
 				{
 					var uv = new MPos(x + Bounds.Left, y + top);

-					// TryGetValue will return Color.Transparent if not found
-					colorsByPosition.TryGetValue(uv, out var actorColor);
+					// FirstOrDefault will return a (MPos.Zero, Color.Transparent) if positions is empty
+					var actorColor = positions.FirstOrDefault(ap => ap.Position == uv).Color;
 					if (actorColor.A == 0)
 						terrainColor = GetTerrainColorPair(uv);

@@ -821,10 +812,10 @@ namespace OpenRA
 					{
 						// Odd rows are shifted right by 1px
 						var dx = uv.V & 1;
-						var xOffset = PxStride * (2 * x + dx);
+						var xOffset = pxStride * (2 * x + dx);
 						if (x + dx > 0)
 						{
-							var z = y * stride + xOffset - PxStride;
+							var z = y * stride + xOffset - pxStride;
 							var c = actorColor.A == 0 ? terrainColor.Left : actorColor;
 							minimapData[z++] = c.R;
 							minimapData[z++] = c.G;
@@ -844,7 +835,7 @@ namespace OpenRA
 					}
 					else
 					{
-						var z = y * stride + PxStride * x;
+						var z = y * stride + pxStride * x;
 						var c = actorColor.A == 0 ? terrainColor.Left : actorColor;
 						minimapData[z++] = c.R;
 						minimapData[z++] = c.G;
@@ -858,28 +849,6 @@ namespace OpenRA
 			return png.Save();
 		}

-		public (int Top, int Bottom) GetCellSpaceBounds()
-		{
-			var top = int.MaxValue;
-			var bottom = int.MinValue;
-
-			// The minimap is drawn in cell space, so we need to
-			// unproject the PPos bounds to find the MPos boundaries.
-			// This matches the calculation in RadarWidget that is used ingame
-			for (var x = Bounds.Left; x < Bounds.Right; x++)
-			{
-				var allTop = Unproject(new PPos(x, Bounds.Top));
-				var allBottom = Unproject(new PPos(x, Bounds.Bottom));
-				if (allTop.Count > 0)
-					top = Math.Min(top, allTop.MinBy(uv => uv.V).V);
-
-				if (allBottom.Count > 0)
-					bottom = Math.Max(bottom, allBottom.MaxBy(uv => uv.V).V);
-			}
-
-			return (top, bottom);
-		}
-
 		public bool Contains(CPos cell)
 		{
 			if (Grid.Type == MapGridType.RectangularIsometric)
@@ -1014,11 +983,11 @@ namespace OpenRA
 		}

 		/// <summary>
-		/// The size of the map Height step in world units.
+		/// The size of the map Height step in world units
 		/// </summary>
 		/// RectangularIsometric defines 1024 units along the diagonal axis,
 		/// giving a half-tile height step of sqrt(2) * 512
-		public WDist CellHeightStep => new(Grid.Type == MapGridType.RectangularIsometric ? 724 : 512);
+		public WDist CellHeightStep => new WDist(Grid.Type == MapGridType.RectangularIsometric ? 724 : 512);

 		public CPos CellContaining(WPos pos)
 		{
@@ -1200,7 +1169,7 @@ namespace OpenRA
 			// Project this guessed cell and take the first available cell
 			// If it is projected outside the layer, then make another guess.
 			var allProjected = ProjectedCellsCovering(uv);
-			var projected = allProjected.Length > 0 ? allProjected[0]
+			var projected = allProjected.Length > 0 ? allProjected.First()
 				: new PPos(uv.U, uv.V.Clamp(Bounds.Top, Bounds.Bottom));

 			// Clamp the projected cell to the map area
@@ -1228,7 +1197,7 @@ namespace OpenRA
 				// This shouldn't happen.  But if it does, return the original value and hope the caller doesn't explode.
 				if (unProjected.Count == 0)
 				{
-					Log.Write("debug", $"Failed to clamp map cell {uv} to map bounds");
+					Log.Write("debug", "Failed to clamp map cell {0} to map bounds", uv);
 					return uv;
 				}
 			}
@@ -1269,9 +1238,9 @@ namespace OpenRA
 			PPos edge;
 			if (allProjected.Length > 0)
 			{
-				var puv = allProjected[0];
-				var horizontalBound = (puv.U - Bounds.Left < Bounds.Width / 2) ? Bounds.Left : Bounds.Right;
-				var verticalBound = (puv.V - Bounds.Top < Bounds.Height / 2) ? Bounds.Top : Bounds.Bottom;
+				var puv = allProjected.First();
+				var horizontalBound = ((puv.U - Bounds.Left) < Bounds.Width / 2) ? Bounds.Left : Bounds.Right;
+				var verticalBound = ((puv.V - Bounds.Top) < Bounds.Height / 2) ? Bounds.Top : Bounds.Bottom;

 				var du = Math.Abs(horizontalBound - puv.U);
 				var dv = Math.Abs(verticalBound - puv.V);
@@ -1300,7 +1269,7 @@ namespace OpenRA
 				// This shouldn't happen.  But if it does, return the original value and hope the caller doesn't explode.
 				if (unProjected.Count == 0)
 				{
-					Log.Write("debug", $"Failed to find closest edge for map cell {uv}");
+					Log.Write("debug", "Failed to find closest edge for map cell {0}", uv);
 					return uv;
 				}
 			}
@@ -1369,18 +1338,13 @@ namespace OpenRA
 				throw new ArgumentOutOfRangeException(nameof(maxRange),
 					$"The requested range ({maxRange}) cannot exceed the value of MaximumTileSearchRange ({Grid.MaximumTileSearchRange})");

-			return FindTilesInAnnulus();
-
-			IEnumerable<CPos> FindTilesInAnnulus()
+			for (var i = minRange; i <= maxRange; i++)
 			{
-				for (var i = minRange; i <= maxRange; i++)
+				foreach (var offset in Grid.TilesByDistance[i])
 				{
-					foreach (var offset in Grid.TilesByDistance[i])
-					{
-						var t = offset + center;
-						if (allowOutsideBounds ? Tiles.Contains(t) : Contains(t))
-							yield return t;
-					}
+					var t = offset + center;
+					if (allowOutsideBounds ? Tiles.Contains(t) : Contains(t))
+						yield return t;
 				}
 			}
 		}
@@ -1436,9 +1400,12 @@ namespace OpenRA
 			return false;
 		}

-		public void Dispose()
+		public string Translate(string key, IDictionary<string, object> args = null)
 		{
-			Sequences.Dispose();
+			if (Translation.TryGetString(key, out var message, args))
+				return message;
+
+			return modData.Translation.GetString(key, args);
 		}
 	}
 }
--- a/OpenRA.Game/Map/MapCache.cs
+++ b/OpenRA.Game/Map/MapCache.cs
@@ -25,33 +25,32 @@ namespace OpenRA
 {
 	public sealed class MapCache : IEnumerable<MapPreview>, IDisposable
 	{
-		public static readonly MapPreview UnknownMap = new(null, null, MapGridType.Rectangular, null);
+		public static readonly MapPreview UnknownMap = new MapPreview(null, null, MapGridType.Rectangular, null);
 		public IReadOnlyDictionary<IReadOnlyPackage, MapClassification> MapLocations => mapLocations;
-		readonly Dictionary<IReadOnlyPackage, MapClassification> mapLocations = new();
-		public bool LoadPreviewImages = true;
+		readonly Dictionary<IReadOnlyPackage, MapClassification> mapLocations = new Dictionary<IReadOnlyPackage, MapClassification>();

 		readonly Cache<string, MapPreview> previews;
 		readonly ModData modData;
 		readonly SheetBuilder sheetBuilder;
 		Thread previewLoaderThread;
 		bool previewLoaderThreadShutDown = true;
-		readonly object syncRoot = new();
-		readonly Queue<MapPreview> generateMinimap = new();
+		readonly object syncRoot = new object();
+		readonly Queue<MapPreview> generateMinimap = new Queue<MapPreview>();

-		public HashSet<string> StringPool { get; } = new();
+		public Dictionary<string, string> StringPool { get; } = new Dictionary<string, string>();

-		readonly List<MapDirectoryTracker> mapDirectoryTrackers = new();
+		readonly List<MapDirectoryTracker> mapDirectoryTrackers = new List<MapDirectoryTracker>();

 		/// <summary>
-		/// The most recently modified or loaded map at runtime.
+		/// The most recenly modified or loaded map at runtime
 		/// </summary>
 		public string LastModifiedMap { get; private set; } = null;
-		readonly Dictionary<string, string> mapUpdates = new();
+		readonly Dictionary<string, string> mapUpdates = new Dictionary<string, string>();

 		string lastLoadedLastModifiedMap;

 		/// <summary>
-		/// If LastModifiedMap was picked already, returns a null.
+		/// If LastModifiedMap was picked already, returns a null
 		/// </summary>
 		public string PickLastModifiedMap(MapVisibility visibility)
 		{
@@ -97,16 +96,16 @@ namespace OpenRA
 					? MapClassification.Unknown : Enum<MapClassification>.Parse(kv.Value);

 				IReadOnlyPackage package;
-				var optional = name.StartsWith('~');
+				var optional = name.StartsWith("~", StringComparison.Ordinal);
 				if (optional)
-					name = name[1..];
+					name = name.Substring(1);

 				try
 				{
 					// HACK: If the path is inside the support directory then we may need to create it
 					// Assume that the path is a directory if there is not an existing file with the same name
 					var resolved = Platform.ResolvePath(name);
-					if (resolved.StartsWith(Platform.SupportDir, StringComparison.Ordinal) && !File.Exists(resolved))
+					if (resolved.StartsWith(Platform.SupportDir) && !File.Exists(resolved))
 						Directory.CreateDirectory(resolved);

 					package = modData.ModFiles.OpenPackage(name);
@@ -123,15 +122,10 @@ namespace OpenRA
 				mapDirectoryTrackers.Add(new MapDirectoryTracker(mapGrid, package, classification));
 			}

-			// PERF: Load the mod YAML once outside the loop, and reuse it when resolving each maps custom YAML.
-			var modDataRules = modData.GetRulesYaml();
 			foreach (var kv in MapLocations)
 			{
 				foreach (var map in kv.Key.Contents)
-				{
-					LoadMapInternal(map, kv.Key, kv.Value, mapGrid, null, modDataRules);
-					GC.Collect();
-				}
+					LoadMap(map, kv.Key, kv.Value, mapGrid, null);
 			}

 			// We only want to track maps in runtime, not at loadtime
@@ -139,27 +133,17 @@ namespace OpenRA
 		}

 		public void LoadMap(string map, IReadOnlyPackage package, MapClassification classification, MapGrid mapGrid, string oldMap)
-		{
-			LoadMapInternal(map, package, classification, mapGrid, oldMap, null);
-		}
-
-		void LoadMapInternal(string map, IReadOnlyPackage package, MapClassification classification, MapGrid mapGrid, string oldMap, IEnumerable<List<MiniYamlNode>> modDataRules)
 		{
 			IReadOnlyPackage mapPackage = null;
 			try
 			{
-				using (new PerfTimer(map))
+				using (new Support.PerfTimer(map))
 				{
 					mapPackage = package.OpenPackage(map, modData.ModFiles);
-					Log.Write("debug", $"Loading Map: {map} FROM {mapPackage.Name}");
-					Console.WriteLine($"Loading Map: {map} FROM {mapPackage.Name}");
 					if (mapPackage != null)
 					{
 						var uid = Map.ComputeUID(mapPackage);
-						previews[uid].UpdateFromMap(mapPackage, package, classification, modData.Manifest.MapCompatibility, mapGrid.Type, modDataRules);
-
-						// Freeing the package to save memory if there is a lot of Maps
-						previews[uid].PackageDispose();
+						previews[uid].UpdateFromMap(mapPackage, package, classification, modData.Manifest.MapCompatibility, mapGrid.Type);

 						if (oldMap != uid)
 						{
@@ -173,16 +157,10 @@ namespace OpenRA
 			catch (Exception e)
 			{
 				mapPackage?.Dispose();
-				Console.WriteLine($"Failed to load map: {map}");
-				Console.WriteLine("Details:");
-				Console.WriteLine(e);
-				Console.WriteLine("StackTrace:");
-				Console.WriteLine(System.Environment.StackTrace);
-				Log.Write("debug", $"Failed to load map: {map}");
-				Log.Write("debug", "Details:");
-				Log.Write("debug", e);
-				Log.Write("debug", "StackTrace:");
-				Log.Write("debug", System.Environment.StackTrace);
+				Console.WriteLine("Failed to load map: {0}", map);
+				Console.WriteLine("Details: {0}", e);
+				Log.Write("debug", "Failed to load map: {0}", map);
+				Log.Write("debug", "Details: {0}", e);
 			}
 		}

@@ -202,13 +180,13 @@ namespace OpenRA
 					continue;

 				var name = kv.Key;
-				var optional = name.StartsWith('~');
+				var optional = name.StartsWith("~", StringComparison.Ordinal);
 				if (optional)
-					name = name[1..];
+					name = name.Substring(1);

 				// Don't try to open the map directory in the support directory if it doesn't exist
 				var resolved = Platform.ResolvePath(name);
-				if (resolved.StartsWith(Platform.SupportDir, StringComparison.Ordinal) && (!Directory.Exists(resolved) || !File.Exists(resolved)))
+				if (resolved.StartsWith(Platform.SupportDir) && (!Directory.Exists(resolved) || !File.Exists(resolved)))
 					continue;

 				using (var package = (IReadWritePackage)modData.ModFiles.OpenPackage(name))
@@ -216,7 +194,7 @@ namespace OpenRA
 			}
 		}

-		public IEnumerable<(IReadWritePackage Package, string Map)> EnumerateMapDirPackagesAndNames(MapClassification classification = MapClassification.System)
+		public IEnumerable<(IReadWritePackage package, string map)> EnumerateMapDirPackagesAndNames(MapClassification classification = MapClassification.System)
 		{
 			var mapDirPackages = EnumerateMapDirPackages(classification);

@@ -235,6 +213,12 @@ namespace OpenRA
 						yield return mapPackage;
 		}

+		public IEnumerable<Map> EnumerateMapsWithoutCaching(MapClassification classification = MapClassification.System)
+		{
+			foreach (var mapPackage in EnumerateMapPackagesWithoutCaching(classification))
+				yield return new Map(modData, mapPackage);
+		}
+
 		public void QueryRemoteMapDetails(string repositoryUrl, IEnumerable<string> uids, Action<MapPreview> mapDetailsReceived = null, Action<MapPreview> mapQueryFailed = null)
 		{
 			var queryUids = uids.Distinct()
@@ -245,12 +229,11 @@ namespace OpenRA
 				.ToList();

 			foreach (var uid in queryUids)
-				previews[uid].UpdateRemoteSearch(MapStatus.Searching, null, null);
+				previews[uid].UpdateRemoteSearch(MapStatus.Searching, null);

 			Task.Run(async () =>
 			{
 				var client = HttpClientFactory.Create();
-				var stringPool = new HashSet<string>(); // Reuse common strings in YAML

 				// Limit each query to 50 maps at a time to avoid request size limits
 				for (var i = 0; i < queryUids.Count; i += 50)
@@ -262,27 +245,26 @@ namespace OpenRA
 						var httpResponseMessage = await client.GetAsync(url);
 						var result = await httpResponseMessage.Content.ReadAsStreamAsync();

-						var yaml = MiniYaml.FromStream(result, url, stringPool: stringPool);
+						var yaml = MiniYaml.FromStream(result);
 						foreach (var kv in yaml)
-							previews[kv.Key].UpdateRemoteSearch(MapStatus.DownloadAvailable, kv.Value, modData.Manifest.MapCompatibility, mapDetailsReceived);
+							previews[kv.Key].UpdateRemoteSearch(MapStatus.DownloadAvailable, kv.Value, mapDetailsReceived);

 						foreach (var uid in batchUids)
 						{
 							var p = previews[uid];
 							if (p.Status != MapStatus.DownloadAvailable)
-								p.UpdateRemoteSearch(MapStatus.Unavailable, null, null);
+								p.UpdateRemoteSearch(MapStatus.Unavailable, null);
 						}
 					}
 					catch (Exception e)
 					{
-						Log.Write("debug", "Remote map query failed with error:");
-						Log.Write("debug", e);
-						Log.Write("debug", $"URL was: {url}");
+						Log.Write("debug", "Remote map query failed with error: {0}", e);
+						Log.Write("debug", "URL was: {0}", url);

 						foreach (var uid in batchUids)
 						{
 							var p = previews[uid];
-							p.UpdateRemoteSearch(MapStatus.Unavailable, null, null);
+							p.UpdateRemoteSearch(MapStatus.Unavailable, null);
 							mapQueryFailed?.Invoke(p);
 						}
 					}
@@ -295,11 +277,11 @@ namespace OpenRA
 			Log.Write("debug", "MapCache.LoadAsyncInternal started");

 			// Milliseconds to wait on one loop when nothing to do
-			const int EmptyDelay = 50;
+			var emptyDelay = 50;

 			// Keep the thread alive for at least 5 seconds after the last minimap generation
-			const int MaxKeepAlive = 5000 / EmptyDelay;
-			var keepAlive = MaxKeepAlive;
+			var maxKeepAlive = 5000 / emptyDelay;
+			var keepAlive = maxKeepAlive;

 			while (true)
 			{
@@ -319,11 +301,11 @@ namespace OpenRA

 				if (todo.Count == 0)
 				{
-					Thread.Sleep(EmptyDelay);
+					Thread.Sleep(emptyDelay);
 					continue;
 				}
 				else
-					keepAlive = MaxKeepAlive;
+					keepAlive = maxKeepAlive;

 				// Render the minimap into the shared sheet
 				foreach (var p in todo)
@@ -338,8 +320,7 @@ namespace OpenRA
 							}
 							catch (Exception e)
 							{
-								Log.Write("debug", "Failed to load minimap with exception:");
-								Log.Write("debug", e);
+								Log.Write("debug", "Failed to load minimap with exception: {0}", e);
 							}
 						});
 					}
@@ -361,8 +342,8 @@ namespace OpenRA

 			while (this[uid].Status != MapStatus.Available)
 			{
-				if (mapUpdates.TryGetValue(uid, out var newUid))
-					uid = newUid;
+				if (mapUpdates.ContainsKey(uid))
+					uid = mapUpdates[uid];
 				else
 					return null;
 			}
@@ -385,6 +366,7 @@ namespace OpenRA
 				{
 					// Wait for any existing thread to exit before starting a new one.
 					previewLoaderThread?.Join();
+
 					previewLoaderThread = new Thread(LoadAsyncInternal)
 					{
 						Name = "Map Preview Loader",
--- a/OpenRA.Game/Map/MapCoordsRegion.cs
+++ b/OpenRA.Game/Map/MapCoordsRegion.cs
@@ -19,6 +19,7 @@ namespace OpenRA
 		public struct MapCoordsEnumerator : IEnumerator<MPos>
 		{
 			readonly MapCoordsRegion r;
+			MPos current;

 			public MapCoordsEnumerator(MapCoordsRegion region)
 				: this()
@@ -29,38 +30,41 @@ namespace OpenRA

 			public bool MoveNext()
 			{
-				var u = Current.U + 1;
-				var v = Current.V;
+				var u = current.U + 1;
+				var v = current.V;

 				// Check for column overflow
-				if (u > r.BottomRight.U)
+				if (u > r.bottomRight.U)
 				{
-					v++;
-					u = r.TopLeft.U;
+					v += 1;
+					u = r.topLeft.U;

 					// Check for row overflow
-					if (v > r.BottomRight.V)
+					if (v > r.bottomRight.V)
 						return false;
 				}

-				Current = new MPos(u, v);
+				current = new MPos(u, v);
 				return true;
 			}

 			public void Reset()
 			{
-				Current = new MPos(r.TopLeft.U - 1, r.TopLeft.V);
+				current = new MPos(r.topLeft.U - 1, r.topLeft.V);
 			}

-			public MPos Current { get; private set; }
-			readonly object IEnumerator.Current => Current;
-			public readonly void Dispose() { }
+			public MPos Current => current;
+			object IEnumerator.Current => Current;
+			public void Dispose() { }
 		}

+		readonly MPos topLeft;
+		readonly MPos bottomRight;
+
 		public MapCoordsRegion(MPos mapTopLeft, MPos mapBottomRight)
 		{
-			TopLeft = mapTopLeft;
-			BottomRight = mapBottomRight;
+			topLeft = mapTopLeft;
+			bottomRight = mapBottomRight;
 		}

 		public override string ToString()
@@ -83,7 +87,7 @@ namespace OpenRA
 			return GetEnumerator();
 		}

-		public MPos TopLeft { get; }
-		public MPos BottomRight { get; }
+		public MPos TopLeft => topLeft;
+		public MPos BottomRight => bottomRight;
 	}
 }
--- a/OpenRA.Game/Map/MapDirectoryTracker.cs
+++ b/OpenRA.Game/Map/MapDirectoryTracker.cs
@@ -25,7 +25,7 @@ namespace OpenRA
 		readonly MapClassification classification;

 		enum MapAction { Add, Delete, Update }
-		readonly Dictionary<string, MapAction> mapActionQueue = new();
+		readonly Dictionary<string, MapAction> mapActionQueue = new Dictionary<string, MapAction>();

 		bool dirty = false;

--- a/OpenRA.Game/Map/MapGrid.cs
+++ b/OpenRA.Game/Map/MapGrid.cs
@@ -29,10 +29,7 @@ namespace OpenRA
 		public readonly WVec[][] Polygons;
 		public readonly WRot Orientation;

-		public CellRamp(MapGridType type, WRot orientation,
-			RampCornerHeight tl = RampCornerHeight.Low, RampCornerHeight tr = RampCornerHeight.Low,
-			RampCornerHeight br = RampCornerHeight.Low, RampCornerHeight bl = RampCornerHeight.Low,
-			RampSplit split = RampSplit.Flat)
+		public CellRamp(MapGridType type, WRot orientation, RampCornerHeight tl = RampCornerHeight.Low, RampCornerHeight tr = RampCornerHeight.Low, RampCornerHeight br = RampCornerHeight.Low,  RampCornerHeight bl = RampCornerHeight.Low, RampSplit split = RampSplit.Flat)
 		{
 			Orientation = orientation;
 			if (type == MapGridType.RectangularIsometric)
@@ -106,7 +103,7 @@ namespace OpenRA
 	public class MapGrid : IGlobalModData
 	{
 		public readonly MapGridType Type = MapGridType.Rectangular;
-		public readonly Size TileSize = new(24, 24);
+		public readonly Size TileSize = new Size(24, 24);
 		public readonly byte MaximumTerrainHeight = 0;
 		public readonly SubCell DefaultSubCell = (SubCell)byte.MaxValue;

@@ -116,26 +113,22 @@ namespace OpenRA

 		public readonly WVec[] SubCellOffsets =
 		{
-			new(0, 0, 0),       // full cell - index 0
-			new(-299, -256, 0), // top left - index 1
-			new(256, -256, 0),  // top right - index 2
-			new(0, 0, 0),       // center - index 3
-			new(-299, 256, 0),  // bottom left - index 4
-			new(256, 256, 0),   // bottom right - index 5
+			new WVec(0, 0, 0),       // full cell - index 0
+			new WVec(-299, -256, 0), // top left - index 1
+			new WVec(256, -256, 0),  // top right - index 2
+			new WVec(0, 0, 0),       // center - index 3
+			new WVec(-299, 256, 0),  // bottom left - index 4
+			new WVec(256, 256, 0),   // bottom right - index 5
 		};

 		public CellRamp[] Ramps { get; }

 		internal readonly CVec[][] TilesByDistance;

-		public int TileScale { get; }
-
 		public MapGrid(MiniYaml yaml)
 		{
 			FieldLoader.Load(this, yaml);

-			TileScale = Type == MapGridType.RectangularIsometric ? 1448 : 1024;
-
 			// The default subcell index defaults to the middle entry
 			var defaultSubCellIndex = (byte)DefaultSubCell;
 			if (defaultSubCellIndex == byte.MaxValue)
--- a/OpenRA.Game/Map/MapPreview.cs
+++ b/OpenRA.Game/Map/MapPreview.cs
@@ -59,13 +59,12 @@ namespace OpenRA
 		public readonly string rules;
 		public readonly string players_block;
 		public readonly int mapformat;
-		public readonly string game_mod;
 	}

-	public sealed class MapPreview : IDisposable, IReadOnlyFileSystem
+	public class MapPreview : IDisposable, IReadOnlyFileSystem
 	{
-		/// <summary>Wrapper that enables map data to be replaced in an atomic fashion.</summary>
-		sealed class InnerData
+		/// <summary>Wrapper that enables map data to be replaced in an atomic fashion</summary>
+		class InnerData
 		{
 			public int MapFormat;
 			public string Title;
@@ -91,7 +90,6 @@ namespace OpenRA
 			public MiniYaml SequenceDefinitions;
 			public MiniYaml ModelSequenceDefinitions;

-			public Translation Translation { get; private set; }
 			public ActorInfo WorldActorInfo { get; private set; }
 			public ActorInfo PlayerActorInfo { get; private set; }

@@ -112,7 +110,7 @@ namespace OpenRA
 				return key == "world" || key == "player";
 			}

-			public void SetCustomRules(ModData modData, IReadOnlyFileSystem fileSystem, Dictionary<string, MiniYaml> yaml, IEnumerable<List<MiniYamlNode>> modDataRules)
+			public void SetCustomRules(ModData modData, IReadOnlyFileSystem fileSystem, Dictionary<string, MiniYaml> yaml)
 			{
 				RuleDefinitions = LoadRuleSection(yaml, "Rules");
 				WeaponDefinitions = LoadRuleSection(yaml, "Weapons");
@@ -122,29 +120,21 @@ namespace OpenRA
 				SequenceDefinitions = LoadRuleSection(yaml, "Sequences");
 				ModelSequenceDefinitions = LoadRuleSection(yaml, "ModelSequences");

-				Translation = yaml.TryGetValue("Translations", out var node) && node != null
-					? new Translation(Game.Settings.Player.Language, FieldLoader.GetValue<string[]>("value", node.Value), fileSystem)
-					: null;
-
 				try
 				{
 					// PERF: Implement a minimal custom loader for custom world and player actors to minimize loading time
 					// This assumes/enforces that these actor types can only inherit abstract definitions (starting with ^)
 					if (RuleDefinitions != null)
 					{
-						modDataRules ??= modData.GetRulesYaml();
-						var files = Enumerable.Empty<string>();
+						var files = modData.Manifest.Rules.AsEnumerable();
 						if (RuleDefinitions.Value != null)
 						{
 							var mapFiles = FieldLoader.GetValue<string[]>("value", RuleDefinitions.Value);
 							files = files.Append(mapFiles);
 						}

-						var stringPool = new HashSet<string>(); // Reuse common strings in YAML
-						var sources =
-							modDataRules.Select(x => x.Where(IsLoadableRuleDefinition).ToList())
-							.Concat(files.Select(s => MiniYaml.FromStream(fileSystem.Open(s), s, stringPool: stringPool).Where(IsLoadableRuleDefinition).ToList()));
-						if (RuleDefinitions.Nodes.Length > 0)
+						var sources = files.Select(s => MiniYaml.FromStream(fileSystem.Open(s), s).Where(IsLoadableRuleDefinition).ToList());
+						if (RuleDefinitions.Nodes.Count > 0)
 							sources = sources.Append(RuleDefinitions.Nodes.Where(IsLoadableRuleDefinition).ToList());

 						var yamlNodes = MiniYaml.Merge(sources);
@@ -155,8 +145,7 @@ namespace OpenRA
 				}
 				catch (Exception e)
 				{
-					Log.Write("debug", $"Failed to load rules for `{Title}` with error:");
-					Log.Write("debug", e);
+					Log.Write("debug", "Failed to load rules for `{0}` with error: {1}", Title, e.Message);
 				}

 				WorldActorInfo = modData.DefaultRules.Actors[SystemActors.World];
@@ -174,23 +163,7 @@ namespace OpenRA
 		readonly ModData modData;

 		public readonly string Uid;
-		public string PackageName { get; private set; }
-		IReadOnlyPackage pPackage;
-		public IReadOnlyPackage Package
-		{
-			get
-			{
-				if (pPackage == null)
-				{
-					pPackage = parentPackage.OpenPackage(PackageName, modData.ModFiles);
-				}
-
-				return pPackage;
-			}
-
-			private set => pPackage = value;
-		}
-
+		public IReadOnlyPackage Package { get; private set; }
 		IReadOnlyPackage parentPackage;

 		volatile InnerData innerData;
@@ -212,7 +185,6 @@ namespace OpenRA

 		public MiniYaml RuleDefinitions => innerData.RuleDefinitions;
 		public MiniYaml WeaponDefinitions => innerData.WeaponDefinitions;
-		public MiniYaml SequenceDefinitions => innerData.SequenceDefinitions;

 		public ActorInfo WorldActorInfo => innerData.WorldActorInfo;
 		public ActorInfo PlayerActorInfo => innerData.PlayerActorInfo;
@@ -221,19 +193,6 @@ namespace OpenRA
 		public long DownloadBytes { get; private set; }
 		public int DownloadPercentage { get; private set; }

-		/// <summary>
-		/// Functionality mirrors <see cref="TranslationProvider.GetString"/>, except instead of using
-		/// loaded <see cref="Map"/>'s translations as backup, we use this <see cref="MapPreview"/>'s.
-		/// </summary>
-		public string GetLocalisedString(string key, IDictionary<string, object> args = null)
-		{
-			// PERF: instead of loading mod level Translation per each MapPreview, reuse the already loaded one in TranslationProvider.
-			if (TranslationProvider.TryGetModString(key, out var message, args))
-				return message;
-
-			return innerData.Translation?.GetString(key, args) ?? key;
-		}
-
 		Sprite minimap;
 		bool generatingMinimap;
 		public Sprite GetMinimap()
@@ -267,14 +226,13 @@ namespace OpenRA
 		{
 			return Ruleset.Load(modData, this, TileSet, innerData.RuleDefinitions,
 				innerData.WeaponDefinitions, innerData.VoiceDefinitions, innerData.NotificationDefinitions,
-				innerData.MusicDefinitions, innerData.ModelSequenceDefinitions);
+				innerData.MusicDefinitions, innerData.SequenceDefinitions, innerData.ModelSequenceDefinitions);
 		}

 		public MapPreview(ModData modData, string uid, MapGridType gridType, MapCache cache)
 		{
 			this.cache = cache;
 			this.modData = modData;
-			this.pPackage = null;

 			Uid = uid;
 			innerData = new InnerData
@@ -301,10 +259,9 @@ namespace OpenRA
 		{
 			this.modData = modData;
 			cache = modData.MapCache;
-			this.pPackage = null;

 			Uid = map.Uid;
-			PackageName = map.Package.Name;
+			Package = map.Package;

 			var mapPlayers = new MapPlayers(map.PlayerDefinitions);
 			var spawns = new List<CPos>();
@@ -335,17 +292,16 @@ namespace OpenRA
 			innerData.SetCustomRules(modData, this, new Dictionary<string, MiniYaml>()
 			{
 				{ "Rules", map.RuleDefinitions },
-				{ "Translations", map.TranslationDefinitions },
 				{ "Weapons", map.WeaponDefinitions },
 				{ "Voices", map.VoiceDefinitions },
 				{ "Music", map.MusicDefinitions },
 				{ "Notifications", map.NotificationDefinitions },
 				{ "Sequences", map.SequenceDefinitions },
 				{ "ModelSequences", map.ModelSequenceDefinitions }
-			}, null);
+			});
 		}

-		public void UpdateFromMap(IReadOnlyPackage p, IReadOnlyPackage parent, MapClassification classification, string[] mapCompatibility, MapGridType gridType, IEnumerable<List<MiniYamlNode>> modDataRules)
+		public void UpdateFromMap(IReadOnlyPackage p, IReadOnlyPackage parent, MapClassification classification, string[] mapCompatibility, MapGridType gridType)
 		{
 			Dictionary<string, MiniYaml> yaml;
 			using (var yamlStream = p.GetStream("map.yaml"))
@@ -353,10 +309,10 @@ namespace OpenRA
 				if (yamlStream == null)
 					throw new FileNotFoundException("Required file map.yaml not present in this map");

-				yaml = new MiniYaml(null, MiniYaml.FromStream(yamlStream, $"{p.Name}:map.yaml", stringPool: cache.StringPool)).ToDictionary();
+				yaml = new MiniYaml(null, MiniYaml.FromStream(yamlStream, "map.yaml", stringPool: cache.StringPool)).ToDictionary();
 			}

-			PackageName = p.Name;
+			Package = p;
 			parentPackage = parent;

 			var newData = innerData.Clone();
@@ -435,9 +391,9 @@ namespace OpenRA
 				newData.Status = MapStatus.Unavailable;
 			}

-			newData.SetCustomRules(modData, this, yaml, modDataRules);
+			newData.SetCustomRules(modData, this, yaml);

-			if (cache.LoadPreviewImages && p.Contains("map.png"))
+			if (p.Contains("map.png"))
 				using (var dataStream = p.GetStream("map.png"))
 					newData.Preview = new Png(dataStream);

@@ -447,7 +403,7 @@ namespace OpenRA
 			innerData = newData;
 		}

-		public void UpdateRemoteSearch(MapStatus status, MiniYaml yaml, string[] mapCompatibility, Action<MapPreview> parseMetadata = null)
+		public void UpdateRemoteSearch(MapStatus status, MiniYaml yaml, Action<MapPreview> parseMetadata = null)
 		{
 			var newData = innerData.Clone();
 			newData.Status = status;
@@ -479,39 +435,26 @@ namespace OpenRA
 						spawns[j / 2] = new CPos(r.spawnpoints[j], r.spawnpoints[j + 1]);
 					newData.SpawnPoints = spawns;
 					newData.GridType = r.map_grid_type;
-					if (cache.LoadPreviewImages)
+					try
 					{
-						try
-						{
-							newData.Preview = new Png(new MemoryStream(Convert.FromBase64String(r.minimap)));
-						}
-						catch (Exception e)
-						{
-							Log.Write("debug", "Failed parsing mapserver minimap response:");
-							Log.Write("debug", e);
-							newData.Preview = null;
-						}
+						newData.Preview = new Png(new MemoryStream(Convert.FromBase64String(r.minimap)));
+					}
+					catch (Exception e)
+					{
+						Log.Write("debug", "Failed parsing mapserver minimap response: {0}", e);
+						newData.Preview = null;
 					}

 					var playersString = Encoding.UTF8.GetString(Convert.FromBase64String(r.players_block));
-					newData.Players = new MapPlayers(MiniYaml.FromString(playersString,
-						$"{yaml.NodeWithKey(nameof(r.players_block)).Location.Name}:{nameof(r.players_block)}"));
+					newData.Players = new MapPlayers(MiniYaml.FromString(playersString));

 					var rulesString = Encoding.UTF8.GetString(Convert.FromBase64String(r.rules));
-					var rulesYaml = new MiniYaml("", MiniYaml.FromString(rulesString,
-						$"{yaml.NodeWithKey(nameof(r.rules)).Location.Name}:{nameof(r.rules)}")).ToDictionary();
-					newData.SetCustomRules(modData, this, rulesYaml, null);
-
-					// Map is for a different mod: update its information so it can be displayed
-					// in the cross-mod server browser UI, but mark it as unavailable so it can't
-					// be selected in a server for the current mod.
-					if (!mapCompatibility.Contains(r.game_mod))
-						newData.Status = MapStatus.Unavailable;
+					var rulesYaml = new MiniYaml("", MiniYaml.FromString(rulesString)).ToDictionary();
+					newData.SetCustomRules(modData, this, rulesYaml);
 				}
 				catch (Exception e)
 				{
-					Log.Write("debug", "Failed parsing mapserver response:");
-					Log.Write("debug", e);
+					Log.Write("debug", "Failed parsing mapserver response: {0}", e);
 				}

 				// Commit updated data before running the callbacks
@@ -534,7 +477,7 @@ namespace OpenRA

 			innerData.Status = MapStatus.Downloading;
 			var installLocation = cache.MapLocations.FirstOrDefault(p => p.Value == MapClassification.User);
-			if (installLocation.Key is not IReadWritePackage mapInstallPackage)
+			if (!(installLocation.Key is IReadWritePackage mapInstallPackage))
 			{
 				Log.Write("debug", "Map install directory not found");
 				innerData.Status = MapStatus.DownloadError;
@@ -578,21 +521,20 @@ namespace OpenRA
 					await response.ReadAsStreamWithProgress(fileStream, OnDownloadProgress, CancellationToken.None);

 					mapInstallPackage.Update(mapFilename, fileStream.ToArray());
-					Log.Write("debug", $"Downloaded map to '{mapFilename}'");
+					Log.Write("debug", "Downloaded map to '{0}'", mapFilename);

 					var package = mapInstallPackage.OpenPackage(mapFilename, modData.ModFiles);
 					if (package == null)
 						innerData.Status = MapStatus.DownloadError;
 					else
 					{
-						UpdateFromMap(package, mapInstallPackage, MapClassification.User, null, GridType, null);
+						UpdateFromMap(package, mapInstallPackage, MapClassification.User, null, GridType);
 						Game.RunAfterTick(onSuccess);
 					}
 				}
 				catch (Exception e)
 				{
-					Log.Write("debug", "Map installation failed with error:");
-					Log.Write("debug", e);
+					Log.Write("debug", "Map installation failed with error: {0}", e);
 					innerData.Status = MapStatus.DownloadError;
 				}
 			});
@@ -605,15 +547,10 @@ namespace OpenRA

 		public void Dispose()
 		{
-			PackageDispose();
-		}
-
-		public void PackageDispose()
-		{
-			if (pPackage != null)
+			if (Package != null)
 			{
-				pPackage.Dispose();
-				pPackage = null;
+				Package.Dispose();
+				Package = null;
 			}
 		}

--- a/OpenRA.Game/Map/PlayerReference.cs
+++ b/OpenRA.Game/Map/PlayerReference.cs
@@ -36,7 +36,7 @@ namespace OpenRA
 		/// <summary>
 		/// Sets the "Home" location, which can be used by traits and scripts to e.g. set the initial camera
 		/// location or choose the map edge for reinforcements.
-		/// This will usually be overridden for client (lobby slot) players with a location based on the Spawn index.
+		/// This will usually be overridden for client (lobby slot) players with a location based on the Spawn index
 		/// </summary>
 		public CPos HomeLocation = CPos.Zero;

--- a/OpenRA.Game/Map/ProjectedCellLayer.cs
+++ b/OpenRA.Game/Map/ProjectedCellLayer.cs
@@ -9,7 +9,6 @@
 */
 #endregion

-using System;
 using OpenRA.Primitives;

 namespace OpenRA
@@ -54,15 +53,5 @@ namespace OpenRA
 		{
 			return Bounds.Contains(uv.U, uv.V);
 		}
-
-		public int IndexOf(T value, int startIndex)
-		{
-			return Array.IndexOf(Entries, value, startIndex);
-		}
-
-		public void SetAll(T value)
-		{
-			Array.Fill(Entries, value);
-		}
 	}
 }
--- a/OpenRA.Game/Map/ProjectedCellRegion.cs
+++ b/OpenRA.Game/Map/ProjectedCellRegion.cs
@@ -59,7 +59,7 @@ namespace OpenRA
 		/// this does not validate whether individual map cells are actually
 		/// projected inside the region.
 		/// </summary>
-		public MapCoordsRegion CandidateMapCoords => new(mapTopLeft, mapBottomRight);
+		public MapCoordsRegion CandidateMapCoords => new MapCoordsRegion(mapTopLeft, mapBottomRight);

 		public ProjectedCellRegionEnumerator GetEnumerator()
 		{
@@ -83,22 +83,24 @@ namespace OpenRA
 			// Current position, in projected map coordinates
 			int u, v;

+			PPos current;
+
 			public ProjectedCellRegionEnumerator(ProjectedCellRegion region)
 				: this()
 			{
 				r = region;
 				Reset();
-				Current = new PPos(u, v);
+				current = new PPos(u, v);
 			}

 			public bool MoveNext()
 			{
-				u++;
+				u += 1;

 				// Check for column overflow
 				if (u > r.BottomRight.U)
 				{
-					v++;
+					v += 1;
 					u = r.TopLeft.U;

 					// Check for row overflow
@@ -106,7 +108,7 @@ namespace OpenRA
 						return false;
 				}

-				Current = new PPos(u, v);
+				current = new PPos(u, v);
 				return true;
 			}

@@ -117,9 +119,9 @@ namespace OpenRA
 				v = r.TopLeft.V;
 			}

-			public PPos Current { get; private set; }
-			readonly object IEnumerator.Current => Current;
-			public readonly void Dispose() { }
+			public PPos Current => current;
+			object IEnumerator.Current => Current;
+			public void Dispose() { }
 		}
 	}
 }
--- a/OpenRA.Game/Map/TerrainInfo.cs
+++ b/OpenRA.Game/Map/TerrainInfo.cs
@@ -60,7 +60,7 @@ namespace OpenRA
 	{
 		public readonly string Type;
 		public readonly BitSet<TargetableType> TargetTypes;
-		public readonly HashSet<string> AcceptsSmudgeType = new();
+		public readonly HashSet<string> AcceptsSmudgeType = new HashSet<string>();
 		public readonly Color Color;
 		public readonly bool RestrictPlayerColor = false;

@@ -69,7 +69,7 @@ namespace OpenRA

 	// HACK: Temporary placeholder to avoid having to change all the traits that reference this constant.
 	// This can be removed after the palette references have been moved from traits to sequences.
-	public static class TileSet
+	public class TileSet
 	{
 		public const string TerrainPaletteInternalName = "terrain";
 	}
--- a/OpenRA.Game/MiniYaml.cs
+++ b/OpenRA.Game/MiniYaml.cs
@@ -11,7 +11,6 @@

 using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.IO;
 using System.Linq;
 using OpenRA.FileSystem;
@@ -20,36 +19,18 @@ namespace OpenRA
 {
 	public static class MiniYamlExts
 	{
-		public static void WriteToFile(this IEnumerable<MiniYamlNode> y, string filename)
+		public static void WriteToFile(this List<MiniYamlNode> y, string filename)
 		{
 			File.WriteAllLines(filename, y.ToLines().Select(x => x.TrimEnd()).ToArray());
 		}

-		public static string WriteToString(this IEnumerable<MiniYamlNode> y)
+		public static string WriteToString(this List<MiniYamlNode> y)
 		{
 			// Remove all trailing newlines and restore the final EOF newline
 			return y.ToLines().JoinWith("\n").TrimEnd('\n') + "\n";
 		}

-		public static IEnumerable<string> ToLines(this IEnumerable<MiniYamlNode> y)
-		{
-			foreach (var kv in y)
-				foreach (var line in kv.Value.ToLines(kv.Key, kv.Comment))
-					yield return line;
-		}
-
-		public static void WriteToFile(this IEnumerable<MiniYamlNodeBuilder> y, string filename)
-		{
-			File.WriteAllLines(filename, y.ToLines().Select(x => x.TrimEnd()).ToArray());
-		}
-
-		public static string WriteToString(this IEnumerable<MiniYamlNodeBuilder> y)
-		{
-			// Remove all trailing newlines and restore the final EOF newline
-			return y.ToLines().JoinWith("\n").TrimEnd('\n') + "\n";
-		}
-
-		public static IEnumerable<string> ToLines(this IEnumerable<MiniYamlNodeBuilder> y)
+		public static IEnumerable<string> ToLines(this List<MiniYamlNode> y)
 		{
 			foreach (var kv in y)
 				foreach (var line in kv.Value.ToLines(kv.Key, kv.Comment))
@@ -57,33 +38,18 @@ namespace OpenRA
 		}
 	}

-	public sealed class MiniYamlNode
+	public class MiniYamlNode
 	{
-		public readonly struct SourceLocation
+		public struct SourceLocation
 		{
-			public readonly string Name;
-			public readonly int Line;
-
-			public SourceLocation(string name, int line)
-			{
-				Name = name;
-				Line = line;
-			}
-
-			public override string ToString() { return $"{Name}:{Line}"; }
+			public string Filename; public int Line;
+			public override string ToString() { return $"{Filename}:{Line}"; }
 		}

-		public readonly SourceLocation Location;
-		public readonly string Key;
-		public readonly MiniYaml Value;
-		public readonly string Comment;
-
-		public MiniYamlNode WithValue(MiniYaml value)
-		{
-			if (Value == value)
-				return this;
-			return new MiniYamlNode(Key, value, Comment, Location);
-		}
+		public SourceLocation Location;
+		public string Key;
+		public MiniYaml Value;
+		public string Comment;

 		public MiniYamlNode(string k, MiniYaml v, string c = null)
 		{
@@ -99,74 +65,42 @@ namespace OpenRA
 		}

 		public MiniYamlNode(string k, string v, string c = null)
-			: this(k, new MiniYaml(v, Enumerable.Empty<MiniYamlNode>()), c) { }
+			: this(k, v, c, null) { }

-		public MiniYamlNode(string k, string v, IEnumerable<MiniYamlNode> n)
+		public MiniYamlNode(string k, string v, List<MiniYamlNode> n)
 			: this(k, new MiniYaml(v, n), null) { }

+		public MiniYamlNode(string k, string v, string c, List<MiniYamlNode> n)
+			: this(k, new MiniYaml(v, n), c) { }
+
+		public MiniYamlNode(string k, string v, string c, List<MiniYamlNode> n, SourceLocation loc)
+			: this(k, new MiniYaml(v, n), c, loc) { }
+
 		public override string ToString()
 		{
 			return $"{{YamlNode: {Key} @ {Location}}}";
 		}
+
+		public MiniYamlNode Clone()
+		{
+			return new MiniYamlNode(Key, Value.Clone(), Comment, Location);
+		}
 	}

-	public sealed class MiniYaml
+	public class MiniYaml
 	{
 		const int SpacesPerLevel = 4;
 		static readonly Func<string, string> StringIdentity = s => s;
 		static readonly Func<MiniYaml, MiniYaml> MiniYamlIdentity = my => my;
+		public string Value;
+		public List<MiniYamlNode> Nodes;

-		public readonly string Value;
-		public readonly ImmutableArray<MiniYamlNode> Nodes;
-
-		public MiniYaml WithValue(string value)
+		public MiniYaml Clone()
 		{
-			if (Value == value)
-				return this;
-			return new MiniYaml(value, Nodes);
-		}
-
-		public MiniYaml WithNodes(IEnumerable<MiniYamlNode> nodes)
-		{
-			if (nodes is ImmutableArray<MiniYamlNode> n && Nodes == n)
-				return this;
-			return new MiniYaml(Value, nodes);
-		}
-
-		public MiniYaml WithNodesAppended(IEnumerable<MiniYamlNode> nodes)
-		{
-			var newNodes = Nodes.AddRange(nodes);
-			if (Nodes == newNodes)
-				return this;
-			return new MiniYaml(Value, newNodes);
-		}
-
-		public MiniYamlNode NodeWithKey(string key)
-		{
-			var result = NodeWithKeyOrDefault(key);
-			if (result == null)
-				throw new InvalidDataException($"No node with key '{key}'");
-			return result;
-		}
-
-		public MiniYamlNode NodeWithKeyOrDefault(string key)
-		{
-			// PERF: Avoid LINQ.
-			var first = true;
-			MiniYamlNode result = null;
+			var clonedNodes = new List<MiniYamlNode>(Nodes.Count);
 			foreach (var node in Nodes)
-			{
-				if (node.Key != key)
-					continue;
-
-				if (!first)
-					throw new InvalidDataException($"Duplicate key '{node.Key}' in {node.Location}");
-
-				first = false;
-				result = node;
-			}
-
-			return result;
+				clonedNodes.Add(node.Clone());
+			return new MiniYaml(Value, clonedNodes);
 		}

 		public Dictionary<string, MiniYaml> ToDictionary()
@@ -182,40 +116,48 @@ namespace OpenRA
 		public Dictionary<TKey, TElement> ToDictionary<TKey, TElement>(
 			Func<string, TKey> keySelector, Func<MiniYaml, TElement> elementSelector)
 		{
-			var ret = new Dictionary<TKey, TElement>(Nodes.Length);
+			var ret = new Dictionary<TKey, TElement>(Nodes.Count);
 			foreach (var y in Nodes)
 			{
 				var key = keySelector(y.Key);
 				var element = elementSelector(y.Value);
-				if (!ret.TryAdd(key, element))
-					throw new InvalidDataException($"Duplicate key '{y.Key}' in {y.Location}");
+				try
+				{
+					ret.Add(key, element);
+				}
+				catch (ArgumentException ex)
+				{
+					throw new InvalidDataException($"Duplicate key '{y.Key}' in {y.Location}", ex);
+				}
 			}

 			return ret;
 		}

 		public MiniYaml(string value)
-			: this(value, Enumerable.Empty<MiniYamlNode>()) { }
+			: this(value, null) { }

-		public MiniYaml(string value, IEnumerable<MiniYamlNode> nodes)
+		public MiniYaml(string value, List<MiniYamlNode> nodes)
 		{
 			Value = value;
-			Nodes = ImmutableArray.CreateRange(nodes);
+			Nodes = nodes ?? new List<MiniYamlNode>();
 		}

-		static List<MiniYamlNode> FromLines(IEnumerable<ReadOnlyMemory<char>> lines, string name, bool discardCommentsAndWhitespace, HashSet<string> stringPool)
+		public static List<MiniYamlNode> NodesOrEmpty(MiniYaml y, string s)
 		{
-			// YAML config often contains repeated strings for key, values, comments.
-			// Pool these strings so we only need one copy of each unique string.
-			// This saves on long-term memory usage as parsed values can often live a long time.
-			// A caller can also provide a pool as input, allowing de-duplication across multiple parses.
-			stringPool ??= new HashSet<string>();
+			var nd = y.ToDictionary();
+			return nd.ContainsKey(s) ? nd[s].Nodes : new List<MiniYamlNode>();
+		}

-			var result = new List<List<MiniYamlNode>>
+		static List<MiniYamlNode> FromLines(IEnumerable<ReadOnlyMemory<char>> lines, string filename, bool discardCommentsAndWhitespace, Dictionary<string, string> stringPool)
+		{
+			if (stringPool == null)
+				stringPool = new Dictionary<string, string>();
+
+			var levels = new List<List<MiniYamlNode>>
 			{
-				new()
+				new List<MiniYamlNode>()
 			};
-			var parsedLines = new List<(int Level, string Key, string Value, string Comment, MiniYamlNode.SourceLocation Location)>();

 			var lineNo = 0;
 			foreach (var ll in lines)
@@ -231,7 +173,7 @@ namespace OpenRA
 				ReadOnlySpan<char> key = default;
 				ReadOnlySpan<char> value = default;
 				ReadOnlySpan<char> comment = default;
-				var location = new MiniYamlNode.SourceLocation(name, lineNo);
+				var location = new MiniYamlNode.SourceLocation { Filename = filename, Line = lineNo };

 				if (line.Length > 0)
 				{
@@ -262,6 +204,15 @@ namespace OpenRA
 						}
 					}

+					if (levels.Count <= level)
+						throw new YamlException($"Bad indent in miniyaml at {location}");
+
+					while (levels.Count > level + 1)
+					{
+						levels[levels.Count - 1].TrimExcess();
+						levels.RemoveAt(levels.Count - 1);
+					}
+
 					// Extract key, value, comment from line as `<key>: <value>#<comment>`
 					// The # character is allowed in the value if escaped (\#).
 					// Leading and trailing whitespace is always trimmed from keys.
@@ -283,7 +234,7 @@ namespace OpenRA
 						if (commentStart < 0 && line[i] == '#' && (i == 0 || line[i - 1] != '\\'))
 						{
 							commentStart = i + 1;
-							if (i <= keyStart + keyLength)
+							if (commentStart <= keyLength)
 								keyLength = i - keyStart;
 							else
 								valueLength = i - valueStart;
@@ -303,13 +254,13 @@ namespace OpenRA
 					}

 					if (commentStart >= 0 && !discardCommentsAndWhitespace)
-						comment = line[commentStart..];
+						comment = line.Slice(commentStart);

 					if (value.Length > 1)
 					{
 						// Remove leading/trailing whitespace guards
 						var trimLeading = value[0] == '\\' && (value[1] == ' ' || value[1] == '\t') ? 1 : 0;
-						var trimTrailing = value[^1] == '\\' && (value[^2] == ' ' || value[^2] == '\t') ? 1 : 0;
+						var trimTrailing = value[value.Length - 1] == '\\' && (value[value.Length - 2] == ' ' || value[value.Length - 2] == '\t') ? 1 : 0;
 						if (trimLeading + trimTrailing > 0)
 							value = value.Slice(trimLeading, value.Length - trimLeading - trimTrailing);

@@ -321,12 +272,6 @@ namespace OpenRA

 				if (!key.IsEmpty || !discardCommentsAndWhitespace)
 				{
-					if (parsedLines.Count > 0 && parsedLines[^1].Level < level - 1)
-						throw new YamlException($"Bad indent in miniyaml at {location}");
-
-					while (parsedLines.Count > 0 && parsedLines[^1].Level > level)
-						BuildCompletedSubNode(level);
-
 					var keyString = key.IsEmpty ? null : key.ToString();
 					var valueString = value.IsEmpty ? null : value.ToString();

@@ -334,75 +279,44 @@ namespace OpenRA
 					// (i.e. a lone # at the end of a line) can be correctly re-serialized
 					var commentString = comment == default ? null : comment.ToString();

-					keyString = keyString == null ? null : stringPool.GetOrAdd(keyString);
-					valueString = valueString == null ? null : stringPool.GetOrAdd(valueString);
-					commentString = commentString == null ? null : stringPool.GetOrAdd(commentString);
+					keyString = keyString == null ? null : stringPool.GetOrAdd(keyString, keyString);
+					valueString = valueString == null ? null : stringPool.GetOrAdd(valueString, valueString);
+					commentString = commentString == null ? null : stringPool.GetOrAdd(commentString, commentString);

-					parsedLines.Add((level, keyString, valueString, commentString, location));
+					var nodes = new List<MiniYamlNode>();
+					levels[level].Add(new MiniYamlNode(keyString, valueString, commentString, nodes, location));
+
+					levels.Add(nodes);
 				}
 			}

-			if (parsedLines.Count > 0)
-				BuildCompletedSubNode(0);
+			foreach (var nodes in levels)
+				nodes.TrimExcess();

-			return result[0];
-
-			void BuildCompletedSubNode(int level)
-			{
-				var lastLevel = parsedLines[^1].Level;
-				while (lastLevel >= result.Count)
-					result.Add(new List<MiniYamlNode>());
-
-				while (parsedLines.Count > 0 && parsedLines[^1].Level >= level)
-				{
-					var parent = parsedLines[^1];
-					var startOfRange = parsedLines.Count - 1;
-					while (startOfRange > 0 && parsedLines[startOfRange - 1].Level == parent.Level)
-						startOfRange--;
-
-					for (var i = startOfRange; i < parsedLines.Count - 1; i++)
-					{
-						var sibling = parsedLines[i];
-						result[parent.Level].Add(
-							new MiniYamlNode(sibling.Key, new MiniYaml(sibling.Value), sibling.Comment, sibling.Location));
-					}
-
-					var childNodes = parent.Level + 1 < result.Count ? result[parent.Level + 1] : null;
-					result[parent.Level].Add(new MiniYamlNode(
-						parent.Key,
-						new MiniYaml(parent.Value, childNodes ?? Enumerable.Empty<MiniYamlNode>()),
-						parent.Comment,
-						parent.Location));
-					childNodes?.Clear();
-
-					parsedLines.RemoveRange(startOfRange, parsedLines.Count - startOfRange);
-				}
-			}
+			return levels[0];
 		}

-		public static List<MiniYamlNode> FromFile(string path, bool discardCommentsAndWhitespace = true, HashSet<string> stringPool = null)
+		public static List<MiniYamlNode> FromFile(string path, bool discardCommentsAndWhitespace = true, Dictionary<string, string> stringPool = null)
 		{
 			return FromStream(File.OpenRead(path), path, discardCommentsAndWhitespace, stringPool);
 		}

-		public static List<MiniYamlNode> FromStream(Stream s, string name, bool discardCommentsAndWhitespace = true, HashSet<string> stringPool = null)
+		public static List<MiniYamlNode> FromStream(Stream s, string fileName = "<no filename available>", bool discardCommentsAndWhitespace = true, Dictionary<string, string> stringPool = null)
 		{
-			return FromLines(s.ReadAllLinesAsMemory(), name, discardCommentsAndWhitespace, stringPool);
+			return FromLines(s.ReadAllLinesAsMemory(), fileName, discardCommentsAndWhitespace, stringPool);
 		}

-		public static List<MiniYamlNode> FromString(string text, string name, bool discardCommentsAndWhitespace = true, HashSet<string> stringPool = null)
+		public static List<MiniYamlNode> FromString(string text, string fileName = "<no filename available>", bool discardCommentsAndWhitespace = true, Dictionary<string, string> stringPool = null)
 		{
-			return FromLines(text.Split(new[] { "\r\n", "\n" }, StringSplitOptions.None).Select(s => s.AsMemory()), name, discardCommentsAndWhitespace, stringPool);
+			return FromLines(text.Split(new[] { "\r\n", "\n" }, StringSplitOptions.None).Select(s => s.AsMemory()), fileName, discardCommentsAndWhitespace, stringPool);
 		}

-		public static List<MiniYamlNode> Merge(IEnumerable<IReadOnlyCollection<MiniYamlNode>> sources)
+		public static List<MiniYamlNode> Merge(IEnumerable<List<MiniYamlNode>> sources)
 		{
-			var sourcesList = sources.ToList();
-			if (sourcesList.Count == 0)
+			if (!sources.Any())
 				return new List<MiniYamlNode>();

-			var tree = sourcesList
-				.Where(s => s != null)
+			var tree = sources.Where(s => s != null)
 				.Select(MergeSelfPartial)
 				.Aggregate(MergePartial)
 				.Where(n => n.Key != null)
@@ -411,39 +325,39 @@ namespace OpenRA
 			var resolved = new Dictionary<string, MiniYaml>(tree.Count);
 			foreach (var kv in tree)
 			{
-				// Inheritance is tracked from parent->child, but not from child->parentsiblings.
-				var inherited = ImmutableDictionary<string, MiniYamlNode.SourceLocation>.Empty.Add(kv.Key, default);
+				var inherited = new Dictionary<string, MiniYamlNode.SourceLocation>
+				{
+					{ kv.Key, default }
+				};
+
 				var children = ResolveInherits(kv.Value, tree, inherited);
 				resolved.Add(kv.Key, new MiniYaml(kv.Value.Value, children));
 			}

 			// Resolve any top-level removals (e.g. removing whole actor blocks)
-			var nodes = new MiniYaml("", resolved.Select(kv => new MiniYamlNode(kv.Key, kv.Value)));
-			return ResolveInherits(nodes, tree, ImmutableDictionary<string, MiniYamlNode.SourceLocation>.Empty);
+			var nodes = new MiniYaml("", resolved.Select(kv => new MiniYamlNode(kv.Key, kv.Value)).ToList());
+			return ResolveInherits(nodes, tree, new Dictionary<string, MiniYamlNode.SourceLocation>());
 		}

-		static void MergeIntoResolved(MiniYamlNode overrideNode, List<MiniYamlNode> existingNodes, HashSet<string> existingNodeKeys,
-			Dictionary<string, MiniYaml> tree, ImmutableDictionary<string, MiniYamlNode.SourceLocation> inherited)
+		static void MergeIntoResolved(MiniYamlNode overrideNode, List<MiniYamlNode> existingNodes,
+			Dictionary<string, MiniYaml> tree, Dictionary<string, MiniYamlNode.SourceLocation> inherited)
 		{
-			if (existingNodeKeys.Add(overrideNode.Key))
+			var existingNode = existingNodes.Find(n => n.Key == overrideNode.Key);
+			if (existingNode != null)
 			{
-				existingNodes.Add(overrideNode);
-				return;
+				existingNode.Value = MergePartial(existingNode.Value, overrideNode.Value);
+				existingNode.Value.Nodes = ResolveInherits(existingNode.Value, tree, inherited);
 			}
-
-			var existingNodeIndex = IndexOfKey(existingNodes, overrideNode.Key);
-			var existingNode = existingNodes[existingNodeIndex];
-			var value = MergePartial(existingNode.Value, overrideNode.Value);
-			var nodes = ResolveInherits(value, tree, inherited);
-			if (!value.Nodes.SequenceEqual(nodes))
-				value = value.WithNodes(nodes);
-			existingNodes[existingNodeIndex] = existingNode.WithValue(value);
+			else
+				existingNodes.Add(overrideNode.Clone());
 		}

-		static List<MiniYamlNode> ResolveInherits(MiniYaml node, Dictionary<string, MiniYaml> tree, ImmutableDictionary<string, MiniYamlNode.SourceLocation> inherited)
+		static List<MiniYamlNode> ResolveInherits(MiniYaml node, Dictionary<string, MiniYaml> tree, Dictionary<string, MiniYamlNode.SourceLocation> inherited)
 		{
-			var resolved = new List<MiniYamlNode>(node.Nodes.Length);
-			var resolvedKeys = new HashSet<string>(node.Nodes.Length);
+			var resolved = new List<MiniYamlNode>(node.Nodes.Count);
+
+			// Inheritance is tracked from parent->child, but not from child->parentsiblings.
+			inherited = new Dictionary<string, MiniYamlNode.SourceLocation>(inherited);

 			foreach (var n in node.Nodes)
 			{
@@ -453,29 +367,24 @@ namespace OpenRA
 						throw new YamlException(
 							$"{n.Location}: Parent type `{n.Value.Value}` not found");

-					try
-					{
-						inherited = inherited.Add(n.Value.Value, n.Location);
-					}
-					catch (ArgumentException)
-					{
+					if (inherited.ContainsKey(n.Value.Value))
 						throw new YamlException($"{n.Location}: Parent type `{n.Value.Value}` was already inherited by this yaml tree at {inherited[n.Value.Value]} (note: may be from a derived tree)");
-					}

+					inherited.Add(n.Value.Value, n.Location);
 					foreach (var r in ResolveInherits(parent, tree, inherited))
-						MergeIntoResolved(r, resolved, resolvedKeys, tree, inherited);
+						MergeIntoResolved(r, resolved, tree, inherited);
 				}
-				else if (n.Key.StartsWith('-'))
+				else if (n.Key.StartsWith("-", StringComparison.Ordinal))
 				{
-					var removed = n.Key[1..];
+					var removed = n.Key.Substring(1);
 					if (resolved.RemoveAll(r => r.Key == removed) == 0)
 						throw new YamlException($"{n.Location}: There are no elements with key `{removed}` to remove");
-					resolvedKeys.Remove(removed);
 				}
 				else
-					MergeIntoResolved(n, resolved, resolvedKeys, tree, inherited);
+					MergeIntoResolved(n, resolved, tree, inherited);
 			}

+			resolved.TrimExcess();
 			return resolved;
 		}

@@ -483,7 +392,7 @@ namespace OpenRA
 		/// Merges any duplicate keys that are defined within the same set of nodes.
 		/// Does not resolve inheritance or node removals.
 		/// </summary>
-		static IReadOnlyCollection<MiniYamlNode> MergeSelfPartial(IReadOnlyCollection<MiniYamlNode> existingNodes)
+		static List<MiniYamlNode> MergeSelfPartial(List<MiniYamlNode> existingNodes)
 		{
 			var keys = new HashSet<string>(existingNodes.Count);
 			var ret = new List<MiniYamlNode>(existingNodes.Count);
@@ -494,20 +403,17 @@ namespace OpenRA
 				else
 				{
 					// Node with the same key has already been added: merge new node over the existing one
-					var originalIndex = IndexOfKey(ret, n.Key);
-					var original = ret[originalIndex];
-					ret[originalIndex] = original.WithValue(MergePartial(original.Value, n.Value));
+					var original = ret.First(r => r.Key == n.Key);
+					original.Value = MergePartial(original.Value, n.Value);
 				}
 			}

+			ret.TrimExcess();
 			return ret;
 		}

 		static MiniYaml MergePartial(MiniYaml existingNodes, MiniYaml overrideNodes)
 		{
-			existingNodes?.Nodes.ToDictionaryWithConflictLog(x => x.Key, "MiniYaml.Merge", null, x => $"{x.Key} (at {x.Location})");
-			overrideNodes?.Nodes.ToDictionaryWithConflictLog(x => x.Key, "MiniYaml.Merge", null, x => $"{x.Key} (at {x.Location})");
-
 			if (existingNodes == null)
 				return overrideNodes;

@@ -517,7 +423,7 @@ namespace OpenRA
 			return new MiniYaml(overrideNodes.Value ?? existingNodes.Value, MergePartial(existingNodes.Nodes, overrideNodes.Nodes));
 		}

-		static IReadOnlyCollection<MiniYamlNode> MergePartial(IReadOnlyCollection<MiniYamlNode> existingNodes, IReadOnlyCollection<MiniYamlNode> overrideNodes)
+		static List<MiniYamlNode> MergePartial(List<MiniYamlNode> existingNodes, List<MiniYamlNode> overrideNodes)
 		{
 			if (existingNodes.Count == 0)
 				return overrideNodes;
@@ -526,67 +432,27 @@ namespace OpenRA
 				return existingNodes;

 			var ret = new List<MiniYamlNode>(existingNodes.Count + overrideNodes.Count);
-			var plainKeys = new HashSet<string>(existingNodes.Count + overrideNodes.Count);

-			foreach (var node in existingNodes)
-				MergeNode(node);
-			foreach (var node in overrideNodes)
-				MergeNode(node);
+			var existingDict = existingNodes.ToDictionaryWithConflictLog(x => x.Key, "MiniYaml.Merge", null, x => $"{x.Key} (at {x.Location})");
+			var overrideDict = overrideNodes.ToDictionaryWithConflictLog(x => x.Key, "MiniYaml.Merge", null, x => $"{x.Key} (at {x.Location})");
+			var allKeys = existingDict.Keys.Union(overrideDict.Keys);

-			void MergeNode(MiniYamlNode node)
+			foreach (var key in allKeys)
 			{
-				// Append Removal nodes to the result.
-				// Therefore: we know the remainder of the method deals with a plain node.
-				if (node.Key.StartsWith('-'))
-				{
-					ret.Add(node);
-					return;
-				}
+				existingDict.TryGetValue(key, out var existingNode);
+				overrideDict.TryGetValue(key, out var overrideNode);

-				// If no previous node with this key is present, it is new and can just be appended.
-				if (plainKeys.Add(node.Key))
-				{
-					ret.Add(node);
-					return;
-				}
-
-				// A Removal node is closer than the previous node.
-				// We should not merge the new node, as the data being merged will jump before the Removal.
-				// Instead, append it so the previous node is applied, then removed, then the new node is applied.
-				var previousNodeIndex = LastIndexOfKey(ret, node.Key);
-				var previousRemovalNodeIndex = LastIndexOfKey(ret, $"-{node.Key}");
-				if (previousRemovalNodeIndex != -1 && previousRemovalNodeIndex > previousNodeIndex)
-				{
-					ret.Add(node);
-					return;
-				}
-
-				// A previous node is present with no intervening Removal.
-				// We should merge the new one into it, in place.
-				ret[previousNodeIndex] = node.WithValue(MergePartial(ret[previousNodeIndex].Value, node.Value));
+				var loc = overrideNode?.Location ?? default;
+				var comment = (overrideNode ?? existingNode).Comment;
+				var merged = (existingNode == null || overrideNode == null) ? overrideNode ?? existingNode :
+					new MiniYamlNode(key, MergePartial(existingNode.Value, overrideNode.Value), comment, loc);
+				ret.Add(merged);
 			}

+			ret.TrimExcess();
 			return ret;
 		}

-		static int IndexOfKey(List<MiniYamlNode> nodes, string key)
-		{
-			// PERF: Avoid LINQ.
-			for (var i = 0; i < nodes.Count; i++)
-				if (nodes[i].Key == key)
-					return i;
-			return -1;
-		}
-
-		static int LastIndexOfKey(List<MiniYamlNode> nodes, string key)
-		{
-			// PERF: Avoid LINQ.
-			for (var i = nodes.Count - 1; i >= 0; i--)
-				if (nodes[i].Key == key)
-					return i;
-			return -1;
-		}
-
 		public IEnumerable<string> ToLines(string key, string comment = null)
 		{
 			var hasKey = !string.IsNullOrEmpty(key);
@@ -609,100 +475,14 @@ namespace OpenRA
 				files = files.Append(mapFiles);
 			}

-			var stringPool = new HashSet<string>(); // Reuse common strings in YAML
-			IEnumerable<IReadOnlyCollection<MiniYamlNode>> yaml = files.Select(s => FromStream(fileSystem.Open(s), s, stringPool: stringPool));
-			if (mapRules != null && mapRules.Nodes.Length > 0)
+			var yaml = files.Select(s => FromStream(fileSystem.Open(s), s));
+			if (mapRules != null && mapRules.Nodes.Count > 0)
 				yaml = yaml.Append(mapRules.Nodes);

 			return Merge(yaml);
 		}
 	}

-	public sealed class MiniYamlNodeBuilder
-	{
-		public MiniYamlNode.SourceLocation Location;
-		public string Key;
-		public MiniYamlBuilder Value;
-		public string Comment;
-
-		public MiniYamlNodeBuilder(MiniYamlNode node)
-		{
-			Location = node.Location;
-			Key = node.Key;
-			Value = new MiniYamlBuilder(node.Value);
-			Comment = node.Comment;
-		}
-
-		public MiniYamlNodeBuilder(string k, MiniYamlBuilder v, string c = null)
-		{
-			Key = k;
-			Value = v;
-			Comment = c;
-		}
-
-		public MiniYamlNodeBuilder(string k, MiniYamlBuilder v, string c, MiniYamlNode.SourceLocation loc)
-			: this(k, v, c)
-		{
-			Location = loc;
-		}
-
-		public MiniYamlNodeBuilder(string k, string v, string c = null)
-			: this(k, new MiniYamlBuilder(v, null), c) { }
-
-		public MiniYamlNodeBuilder(string k, string v, List<MiniYamlNode> n)
-			: this(k, new MiniYamlBuilder(v, n), null) { }
-
-		public MiniYamlNode Build()
-		{
-			return new MiniYamlNode(Key, Value.Build(), Comment, Location);
-		}
-	}
-
-	public sealed class MiniYamlBuilder
-	{
-		public string Value;
-		public List<MiniYamlNodeBuilder> Nodes;
-
-		public MiniYamlBuilder(MiniYaml yaml)
-		{
-			Value = yaml.Value;
-			Nodes = yaml.Nodes.Select(n => new MiniYamlNodeBuilder(n)).ToList();
-		}
-
-		public MiniYamlBuilder(string value)
-			: this(value, null) { }
-
-		public MiniYamlBuilder(string value, List<MiniYamlNode> nodes)
-		{
-			Value = value;
-			Nodes = nodes == null ? new List<MiniYamlNodeBuilder>() : nodes.ConvertAll(x => new MiniYamlNodeBuilder(x));
-		}
-
-		public MiniYaml Build()
-		{
-			return new MiniYaml(Value, Nodes.Select(n => n.Build()));
-		}
-
-		public IEnumerable<string> ToLines(string key, string comment = null)
-		{
-			var hasKey = !string.IsNullOrEmpty(key);
-			var hasValue = !string.IsNullOrEmpty(Value);
-			var hasComment = comment != null;
-			yield return (hasKey ? key + ":" : "")
-				+ (hasValue ? " " + Value.Replace("#", "\\#") : "")
-				+ (hasComment ? (hasKey || hasValue ? " " : "") + "#" + comment : "");
-
-			if (Nodes != null)
-				foreach (var line in Nodes.ToLines())
-					yield return "\t" + line;
-		}
-
-		public MiniYamlNodeBuilder NodeWithKeyOrDefault(string key)
-		{
-			return Nodes.SingleOrDefault(n => n.Key == key);
-		}
-	}
-
 	[Serializable]
 	public class YamlException : Exception
 	{
--- a/OpenRA.Game/ModData.cs
+++ b/OpenRA.Game/ModData.cs
@@ -33,8 +33,10 @@ namespace OpenRA
 		public readonly ISpriteLoader[] SpriteLoaders;
 		public readonly ITerrainLoader TerrainLoader;
 		public readonly ISpriteSequenceLoader SpriteSequenceLoader;
+		public readonly IModelSequenceLoader ModelSequenceLoader;
 		public readonly IVideoLoader[] VideoLoaders;
 		public readonly HotkeyManager Hotkeys;
+		public readonly Translation Translation;
 		public ILoadScreen LoadScreen { get; }
 		public CursorProvider CursorProvider { get; private set; }
 		public FS ModFiles;
@@ -46,6 +48,9 @@ namespace OpenRA
 		readonly Lazy<IReadOnlyDictionary<string, ITerrainInfo>> defaultTerrainInfo;
 		public IReadOnlyDictionary<string, ITerrainInfo> DefaultTerrainInfo => defaultTerrainInfo.Value;

+		readonly Lazy<IReadOnlyDictionary<string, SequenceProvider>> defaultSequences;
+		public IReadOnlyDictionary<string, SequenceProvider> DefaultSequences => defaultSequences.Value;
+
 		public ModData(Manifest mod, InstalledMods mods, bool useLoadScreen = false)
 		{
 			Languages = Array.Empty<string>();
@@ -89,8 +94,19 @@ namespace OpenRA

 			SpriteSequenceLoader = (ISpriteSequenceLoader)sequenceCtor.Invoke(new[] { this });

+			var modelFormat = Manifest.Get<ModelSequenceFormat>();
+			var modelLoader = ObjectCreator.FindType(modelFormat.Type + "Loader");
+			var modelCtor = modelLoader?.GetConstructor(new[] { typeof(ModData) });
+			if (modelLoader == null || !modelLoader.GetInterfaces().Contains(typeof(IModelSequenceLoader)) || modelCtor == null)
+				throw new InvalidOperationException($"Unable to find a model loader for type '{modelFormat.Type}'.");
+
+			ModelSequenceLoader = (IModelSequenceLoader)modelCtor.Invoke(new[] { this });
+			ModelSequenceLoader.OnMissingModelError = s => Log.Write("debug", s);
+
 			Hotkeys = new HotkeyManager(ModFiles, Game.Settings.Keys, Manifest);

+			Translation = new Translation(Game.Settings.Player.Language, Manifest.Translations, DefaultFileSystem);
+
 			defaultRules = Exts.Lazy(() => Ruleset.LoadDefaults(this));
 			defaultTerrainInfo = Exts.Lazy(() =>
 			{
@@ -102,7 +118,13 @@ namespace OpenRA
 					items.Add(t.Id, t);
 				}

-				return (IReadOnlyDictionary<string, ITerrainInfo>)new ReadOnlyDictionary<string, ITerrainInfo>(items);
+				return (IReadOnlyDictionary<string, ITerrainInfo>)(new ReadOnlyDictionary<string, ITerrainInfo>(items));
+			});
+
+			defaultSequences = Exts.Lazy(() =>
+			{
+				var items = DefaultTerrainInfo.ToDictionary(t => t.Key, t => new SequenceProvider(DefaultFileSystem, this, t.Key, null));
+				return (IReadOnlyDictionary<string, SequenceProvider>)(new ReadOnlyDictionary<string, SequenceProvider>(items));
 			});

 			initialThreadId = Environment.CurrentManagedThreadId;
@@ -124,7 +146,6 @@ namespace OpenRA
 			// horribly when you use ModData in unexpected ways.
 			ChromeMetrics.Initialize(this);
 			ChromeProvider.Initialize(this);
-			TranslationProvider.Initialize(this, fileSystem);

 			Game.Sound.Initialize(SoundLoaders, fileSystem);

@@ -146,7 +167,6 @@ namespace OpenRA

 			// Reinitialize all our assets
 			InitializeLoaders(map);
-			map.Sequences.LoadSprites();

 			// Load music with map assets mounted
 			using (new Support.PerfTimer("Map.Music"))
@@ -156,12 +176,6 @@ namespace OpenRA
 			return map;
 		}

-		public List<MiniYamlNode>[] GetRulesYaml()
-		{
-			var stringPool = new HashSet<string>(); // Reuse common strings in YAML
-			return Manifest.Rules.Select(s => MiniYaml.FromStream(DefaultFileSystem.Open(s), s, stringPool: stringPool)).ToArray();
-		}
-
 		public void Dispose()
 		{
 			LoadScreen?.Dispose();
--- a/OpenRA.Game/Network/Connection.cs
+++ b/OpenRA.Game/Network/Connection.cs
@@ -42,9 +42,9 @@ namespace OpenRA.Network
 	public sealed class EchoConnection : IConnection
 	{
 		const int LocalClientId = 1;
-		readonly Queue<(int Frame, int SyncHash, ulong DefeatState)> sync = new();
-		readonly Queue<(int Frame, OrderPacket Orders)> orders = new();
-		readonly Queue<OrderPacket> immediateOrders = new();
+		readonly Queue<(int Frame, int SyncHash, ulong DefeatState)> sync = new Queue<(int, int, ulong)>();
+		readonly Queue<(int Frame, OrderPacket Orders)> orders = new Queue<(int, OrderPacket)>();
+		readonly Queue<OrderPacket> immediateOrders = new Queue<OrderPacket>();
 		bool disposed;

 		int IConnection.LocalClientId => LocalClientId;
@@ -100,16 +100,19 @@ namespace OpenRA.Network
 	{
 		public readonly ConnectionTarget Target;
 		internal ReplayRecorder Recorder { get; private set; }
-		readonly Queue<(int Frame, int SyncHash, ulong DefeatState)> sentSync = new();
-		readonly Queue<(int Frame, int SyncHash, ulong DefeatState)> queuedSyncPackets = new();
+		readonly Queue<(int Frame, int SyncHash, ulong DefeatState)> sentSync = new Queue<(int, int, ulong)>();
+		readonly Queue<(int Frame, int SyncHash, ulong DefeatState)> queuedSyncPackets = new Queue<(int, int, ulong)>();

-		readonly Queue<(int Frame, OrderPacket Orders)> sentOrders = new();
-		readonly Queue<OrderPacket> sentImmediateOrders = new();
-		readonly ConcurrentQueue<(int FromClient, byte[] Data)> receivedPackets = new();
+		readonly Queue<(int Frame, OrderPacket Orders)> sentOrders = new Queue<(int, OrderPacket)>();
+		readonly Queue<OrderPacket> sentImmediateOrders = new Queue<OrderPacket>();
+		readonly ConcurrentQueue<(int FromClient, byte[] Data)> receivedPackets = new ConcurrentQueue<(int, byte[])>();
 		TcpClient tcp;
+		IPEndPoint endpoint;
+
 		volatile ConnectionState connectionState = ConnectionState.Connecting;
 		volatile int clientId;
 		bool disposed;
+		string errorMessage;

 		public NetworkConnection(ConnectionTarget target)
 		{
@@ -121,12 +124,6 @@ namespace OpenRA.Network
 			}.Start();
 		}

-		public ConnectionState ConnectionState => connectionState;
-
-		public IPEndPoint EndPoint { get; private set; }
-
-		public string ErrorMessage { get; private set; }
-
 		void NetworkConnectionConnect()
 		{
 			var queue = new BlockingCollection<TcpClient>();
@@ -154,7 +151,7 @@ namespace OpenRA.Network
 					}
 					catch (Exception ex)
 					{
-						ErrorMessage = "Failed to connect";
+						errorMessage = "Failed to connect";
 						Log.Write("client", $"Failed to connect to {endpoint}: {ex.Message}");
 					}
 				})
@@ -166,7 +163,7 @@ namespace OpenRA.Network

 			if (!atLeastOneEndpoint)
 			{
-				ErrorMessage = "Failed to resolve address";
+				errorMessage = "Failed to resolve address";
 				connectionState = ConnectionState.NotConnected;
 			}

@@ -174,7 +171,7 @@ namespace OpenRA.Network
 			else if (queue.TryTake(out tcp, 5000))
 			{
 				// Copy endpoint here to have it even after getting disconnected.
-				EndPoint = (IPEndPoint)tcp.Client.RemoteEndPoint;
+				endpoint = (IPEndPoint)tcp.Client.RemoteEndPoint;

 				new Thread(NetworkConnectionReceive)
 				{
@@ -218,8 +215,8 @@ namespace OpenRA.Network
 			}
 			catch (Exception ex)
 			{
-				ErrorMessage = "Connection failed";
-				Log.Write("client", $"Connection to {EndPoint} failed: {ex.Message}");
+				errorMessage = "Connection failed";
+				Log.Write("client", $"Connection to {endpoint} failed: {ex.Message}");
 			}
 			finally
 			{
@@ -260,15 +257,15 @@ namespace OpenRA.Network
 			try
 			{
 				var ms = new MemoryStream();
-				ms.Write(packet.Length);
-				ms.Write(packet);
+				ms.WriteArray(BitConverter.GetBytes(packet.Length));
+				ms.WriteArray(packet);

 				foreach (var s in queuedSyncPackets)
 				{
 					var q = OrderIO.SerializeSync(s);

-					ms.Write(q.Length);
-					ms.Write(q);
+					ms.WriteArray(BitConverter.GetBytes(q.Length));
+					ms.WriteArray(q);

 					sentSync.Enqueue(s);
 				}
@@ -370,6 +367,12 @@ namespace OpenRA.Network
 			Recorder = new ReplayRecorder(chooseFilename);
 		}

+		public ConnectionState ConnectionState => connectionState;
+
+		public IPEndPoint EndPoint => endpoint;
+
+		public string ErrorMessage => errorMessage;
+
 		void IDisposable.Dispose()
 		{
 			if (disposed)
--- a/OpenRA.Game/Network/GameSave.cs
+++ b/OpenRA.Game/Network/GameSave.cs
@@ -81,7 +81,7 @@ namespace OpenRA.Network
 		public const int MetadataMarker = -1;
 		public const int TraitDataMarker = -3;

-		readonly MemoryStream ordersStream = new();
+		readonly MemoryStream ordersStream = new MemoryStream();

 		// Loaded from file and updated during gameplay
 		public int LastOrdersFrame { get; private set; }
@@ -92,7 +92,7 @@ namespace OpenRA.Network
 		public Session.Global GlobalSettings { get; private set; }
 		public Dictionary<string, Session.Slot> Slots { get; private set; }
 		public Dictionary<string, SlotClient> SlotClients { get; private set; }
-		public Dictionary<int, MiniYaml> TraitData = new();
+		public Dictionary<int, MiniYaml> TraitData = new Dictionary<int, MiniYaml>();

 		// Set on game start
 		int[] clientsBySlotIndex = Array.Empty<int>();
@@ -122,10 +122,10 @@ namespace OpenRA.Network
 				LastSyncFrame = rs.ReadInt32();
 				lastSyncPacket = rs.ReadBytes(Order.SyncHashOrderLength);

-				var globalSettings = MiniYaml.FromString(rs.ReadLengthPrefixedString(Encoding.UTF8, Connection.MaxOrderLength), $"{filepath}:globalSettings");
+				var globalSettings = MiniYaml.FromString(rs.ReadString(Encoding.UTF8, Connection.MaxOrderLength));
 				GlobalSettings = Session.Global.Deserialize(globalSettings[0].Value);

-				var slots = MiniYaml.FromString(rs.ReadLengthPrefixedString(Encoding.UTF8, Connection.MaxOrderLength), $"{filepath}:slots");
+				var slots = MiniYaml.FromString(rs.ReadString(Encoding.UTF8, Connection.MaxOrderLength));
 				Slots = new Dictionary<string, Session.Slot>();
 				foreach (var s in slots)
 				{
@@ -133,7 +133,7 @@ namespace OpenRA.Network
 					Slots.Add(slot.PlayerReference, slot);
 				}

-				var slotClients = MiniYaml.FromString(rs.ReadLengthPrefixedString(Encoding.UTF8, Connection.MaxOrderLength), $"{filepath}:slotClients");
+				var slotClients = MiniYaml.FromString(rs.ReadString(Encoding.UTF8, Connection.MaxOrderLength));
 				SlotClients = new Dictionary<string, SlotClient>();
 				foreach (var s in slotClients)
 				{
@@ -144,9 +144,9 @@ namespace OpenRA.Network
 				if (rs.Position != traitDataOffset || rs.ReadInt32() != TraitDataMarker)
 					throw new InvalidDataException("Invalid orasav file");

-				var traitData = MiniYaml.FromString(rs.ReadLengthPrefixedString(Encoding.UTF8, Connection.MaxOrderLength), $"{filepath}:traitData");
+				var traitData = MiniYaml.FromString(rs.ReadString(Encoding.UTF8, Connection.MaxOrderLength));
 				foreach (var td in traitData)
-					TraitData.Add(Exts.ParseInt32Invariant(td.Key), td.Value);
+					TraitData.Add(int.Parse(td.Key), td.Value);

 				rs.Seek(0, SeekOrigin.Begin);
 				ordersStream.Write(rs.ReadBytes(metadataOffset), 0, metadataOffset);
@@ -226,10 +226,10 @@ namespace OpenRA.Network
 				clientSlot = firstBotSlotIndex;
 			}

-			ordersStream.Write(data.Length + 8);
-			ordersStream.Write(frame);
-			ordersStream.Write(clientSlot);
-			ordersStream.Write(data);
+			ordersStream.WriteArray(BitConverter.GetBytes(data.Length + 8));
+			ordersStream.WriteArray(BitConverter.GetBytes(frame));
+			ordersStream.WriteArray(BitConverter.GetBytes(clientSlot));
+			ordersStream.WriteArray(data);
 			LastOrdersFrame = frame;
 		}

@@ -238,7 +238,7 @@ namespace OpenRA.Network
 			// Send the trait data first to guarantee that it is available when needed
 			foreach (var kv in TraitData)
 			{
-				var data = new List<MiniYamlNode>() { new(kv.Key.ToStringInvariant(), kv.Value) }.WriteToString();
+				var data = new List<MiniYamlNode>() { new MiniYamlNode(kv.Key.ToString(), kv.Value) }.WriteToString();
 				packetFn(0, 0, Order.FromTargetString("SaveTraitData", data, true).Serialize());
 			}

@@ -284,40 +284,39 @@ namespace OpenRA.Network
 			// - File offset of metadata start marker
 			// - File offset of custom trait data
 			// - Metadata end marker
-			using (var file = File.Create(path))
-			{
-				ordersStream.Seek(0, SeekOrigin.Begin);
-				ordersStream.CopyTo(file);
-				file.Write(MetadataMarker);
-				file.Write(LastOrdersFrame);
-				file.Write(LastSyncFrame);
-				file.Write(lastSyncPacket, 0, Order.SyncHashOrderLength);
+			var file = File.Create(path);

-				var globalSettingsNodes = new List<MiniYamlNode>() { GlobalSettings.Serialize() };
-				file.WriteLengthPrefixedString(Encoding.UTF8, globalSettingsNodes.WriteToString());
+			ordersStream.Seek(0, SeekOrigin.Begin);
+			ordersStream.CopyTo(file);
+			file.Write(BitConverter.GetBytes(MetadataMarker), 0, 4);
+			file.Write(BitConverter.GetBytes(LastOrdersFrame), 0, 4);
+			file.Write(BitConverter.GetBytes(LastSyncFrame), 0, 4);
+			file.Write(lastSyncPacket, 0, Order.SyncHashOrderLength);

-				var slotNodes = Slots
-					.Select(s => s.Value.Serialize())
-					.ToList();
-				file.WriteLengthPrefixedString(Encoding.UTF8, slotNodes.WriteToString());
+			var globalSettingsNodes = new List<MiniYamlNode>() { GlobalSettings.Serialize() };
+			file.WriteString(Encoding.UTF8, globalSettingsNodes.WriteToString());

-				var slotClientNodes = SlotClients
-					.Select(s => s.Value.Serialize(s.Key))
-					.ToList();
-				file.WriteLengthPrefixedString(Encoding.UTF8, slotClientNodes.WriteToString());
+			var slotNodes = Slots
+				.Select(s => s.Value.Serialize())
+				.ToList();
+			file.WriteString(Encoding.UTF8, slotNodes.WriteToString());

-				var traitDataOffset = file.Length;
-				file.Write(TraitDataMarker);
+			var slotClientNodes = SlotClients
+				.Select(s => s.Value.Serialize(s.Key))
+				.ToList();
+			file.WriteString(Encoding.UTF8, slotClientNodes.WriteToString());

-				var traitDataNodes = TraitData
-					.Select(kv => new MiniYamlNode(kv.Key.ToStringInvariant(), kv.Value))
-					.ToList();
-				file.WriteLengthPrefixedString(Encoding.UTF8, traitDataNodes.WriteToString());
+			var traitDataOffset = file.Length;
+			file.Write(BitConverter.GetBytes(TraitDataMarker), 0, 4);

-				file.Write((int)ordersStream.Length);
-				file.Write((int)traitDataOffset);
-				file.Write(EOFMarker);
-			}
+			var traitDataNodes = TraitData
+				.Select(kv => new MiniYamlNode(kv.Key.ToString(), kv.Value))
+				.ToList();
+			file.WriteString(Encoding.UTF8, traitDataNodes.WriteToString());
+
+			file.Write(BitConverter.GetBytes(ordersStream.Length), 0, 4);
+			file.Write(BitConverter.GetBytes(traitDataOffset), 0, 4);
+			file.Write(BitConverter.GetBytes(EOFMarker), 0, 4);
 		}
 	}
 }
--- a/OpenRA.Game/Network/GameServer.cs
+++ b/OpenRA.Game/Network/GameServer.cs
@@ -61,34 +61,34 @@ namespace OpenRA.Network

 		public const int ProtocolVersion = 2;

-		/// <summary>Online game number or -1 for LAN games.</summary>
+		/// <summary>Online game number or -1 for LAN games</summary>
 		public readonly int Id = -1;

-		/// <summary>Name of the server.</summary>
+		/// <summary>Name of the server</summary>
 		public readonly string Name = null;

 		/// <summary>ip:port string to connect to.</summary>
 		public readonly string Address = null;

-		/// <summary>Port of the server.</summary>
+		/// <summary>Port of the server</summary>
 		public readonly int Port = 0;

-		/// <summary>The current state of the server (waiting/playing/completed).</summary>
+		/// <summary>The current state of the server (waiting/playing/completed)</summary>
 		public readonly int State = 0;

-		/// <summary>The number of slots available for non-bot players.</summary>
+		/// <summary>The number of slots available for non-bot players</summary>
 		public readonly int MaxPlayers = 0;

-		/// <summary>UID of the map.</summary>
+		/// <summary>UID of the map</summary>
 		public readonly string Map = null;

-		/// <summary>Mod ID.</summary>
+		/// <summary>Mod ID</summary>
 		public readonly string Mod = "";

-		/// <summary>Mod Version.</summary>
+		/// <summary>Mod Version</summary>
 		public readonly string Version = "";

-		/// <summary>Human-readable mod title.</summary>
+		/// <summary>Human-readable mod title</summary>
 		public readonly string ModTitle = "";

 		/// <summary>URL to show in game listings for custom/unknown mods.</summary>
@@ -100,13 +100,13 @@ namespace OpenRA.Network
 		/// <summary>GeoIP resolved server location.</summary>
 		public readonly string Location = "";

-		/// <summary>Password protected.</summary>
+		/// <summary>Password protected</summary>
 		public readonly bool Protected = false;

-		/// <summary>Players must be authenticated with the OpenRA forum.</summary>
+		/// <summary>Players must be authenticated with the OpenRA forum</summary>
 		public readonly bool Authentication = false;

-		/// <summary>UTC datetime string when the game changed to the Playing state.</summary>
+		/// <summary>UTC datetime string when the game changed to the Playing state</summary>
 		public readonly string Started = null;

 		/// <summary>Number of non-spectator, non-bot players. Only defined if GameServer is parsed from yaml.</summary>
@@ -132,7 +132,7 @@ namespace OpenRA.Network
 		[FieldLoader.LoadUsing(nameof(LoadClients))]
 		public readonly GameClient[] Clients;

-		/// <summary>The list of spawnpoints that are disabled for this game.</summary>
+		/// <summary>The list of spawnpoints that are disabled for this game</summary>
 		public readonly int[] DisabledSpawnPoints = Array.Empty<int>();

 		public string ModLabel => $"{ModTitle} ({Version})";
@@ -140,7 +140,7 @@ namespace OpenRA.Network
 		static object LoadClients(MiniYaml yaml)
 		{
 			var clients = new List<GameClient>();
-			var clientsNode = yaml.NodeWithKeyOrDefault("Clients");
+			var clientsNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Clients");
 			if (clientsNode != null)
 			{
 				var regex = new Regex(@"Client@\d+");
@@ -159,7 +159,7 @@ namespace OpenRA.Network
 			// Games advertised using the old API used a single Mods field
 			if (Mod == null || Version == null)
 			{
-				var modsNode = yaml.NodeWithKeyOrDefault("Mods");
+				var modsNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Mods");
 				if (modsNode != null)
 				{
 					var modVersion = modsNode.Value.Value.Split('@');
@@ -169,8 +169,9 @@ namespace OpenRA.Network
 			}

 			// Games advertised using the old API calculated the play time locally
-			if (State == 2 && PlayTime < 0 && DateTime.TryParse(Started, out var startTime))
-				PlayTime = (int)(DateTime.UtcNow - startTime).TotalSeconds;
+			if (State == 2 && PlayTime < 0)
+				if (DateTime.TryParse(Started, out var startTime))
+					PlayTime = (int)(DateTime.UtcNow - startTime).TotalSeconds;

 			var externalKey = ExternalMod.MakeKey(Mod, Version);
 			if (Game.ExternalMods.TryGetValue(externalKey, out var external) && external.Version == Version)
@@ -216,7 +217,7 @@ namespace OpenRA.Network
 			Name = server.Settings.Name;

 			// IP address will be replaced with a real value by the master server / receiving LAN client
-			Address = "0.0.0.0:" + server.Settings.ListenPort.ToStringInvariant();
+			Address = "0.0.0.0:" + server.Settings.ListenPort.ToString();
 			State = (int)server.State;
 			MaxPlayers = server.LobbyInfo.Slots.Count(s => !s.Value.Closed) - server.LobbyInfo.Clients.Count(c1 => c1.Bot != null);
 			Map = server.Map.Uid;
@@ -233,7 +234,7 @@ namespace OpenRA.Network

 		public string ToPOSTData(bool lanGame)
 		{
-			var root = new List<MiniYamlNode>() { new("Protocol", ProtocolVersion.ToStringInvariant()) };
+			var root = new List<MiniYamlNode>() { new MiniYamlNode("Protocol", ProtocolVersion.ToString()) };
 			foreach (var field in SerializeFields)
 				root.Add(FieldSaver.SaveField(this, field));

@@ -242,16 +243,18 @@ namespace OpenRA.Network
 				// Add fields that are normally generated by the master server
 				// LAN games overload the Id with a GUID string (rather than an ID) to allow deduplication
 				root.Add(new MiniYamlNode("Id", Platform.SessionGUID.ToString()));
-				root.Add(new MiniYamlNode("Players", Clients.Count(c => !c.IsBot && !c.IsSpectator).ToStringInvariant()));
-				root.Add(new MiniYamlNode("Spectators", Clients.Count(c => c.IsSpectator).ToStringInvariant()));
-				root.Add(new MiniYamlNode("Bots", Clients.Count(c => c.IsBot).ToStringInvariant()));
+				root.Add(new MiniYamlNode("Players", Clients.Count(c => !c.IsBot && !c.IsSpectator).ToString()));
+				root.Add(new MiniYamlNode("Spectators", Clients.Count(c => c.IsSpectator).ToString()));
+				root.Add(new MiniYamlNode("Bots", Clients.Count(c => c.IsBot).ToString()));

 				// Included for backwards compatibility with older clients that don't support separated Mod/Version.
 				root.Add(new MiniYamlNode("Mods", Mod + "@" + Version));
 			}

-			var clientsNode = new MiniYaml("", Clients.Select((c, i) =>
-				new MiniYamlNode("Client@" + i, FieldSaver.Save(c))));
+			var clientsNode = new MiniYaml("");
+			var i = 0;
+			foreach (var c in Clients)
+				clientsNode.Nodes.Add(new MiniYamlNode("Client@" + (i++).ToString(), FieldSaver.Save(c)));

 			root.Add(new MiniYamlNode("Clients", clientsNode));
 			return new MiniYaml("", root)
--- a/OpenRA.Game/Network/GeoIP.cs
+++ b/OpenRA.Game/Network/GeoIP.cs
@@ -19,9 +19,9 @@ using ICSharpCode.SharpZipLib.Zip;

 namespace OpenRA.Network
 {
-	public static class GeoIP
+	public class GeoIP
 	{
-		sealed class IP2LocationReader
+		class IP2LocationReader
 		{
 			public readonly DateTime Date;
 			readonly Stream stream;
@@ -128,8 +128,7 @@ namespace OpenRA.Network
 			}
 			catch (Exception e)
 			{
-				Log.Write("geoip", "DatabaseReader failed:");
-				Log.Write("geoip", e);
+				Log.Write("geoip", "DatabaseReader failed: {0}", e);
 			}
 		}

@@ -143,8 +142,7 @@ namespace OpenRA.Network
 				}
 				catch (Exception e)
 				{
-					Log.Write("geoip", "LookupCountry failed:");
-					Log.Write("geoip", e);
+					Log.Write("geoip", "LookupCountry failed: {0}", e);
 				}
 			}

--- a/OpenRA.Game/Network/Handshake.cs
+++ b/OpenRA.Game/Network/Handshake.cs
@@ -20,16 +20,16 @@ namespace OpenRA.Network
 		public string Version;
 		public string AuthToken;

-		public static HandshakeRequest Deserialize(string data, string name)
+		public static HandshakeRequest Deserialize(string data)
 		{
 			var handshake = new HandshakeRequest();
-			FieldLoader.Load(handshake, MiniYaml.FromString(data, name).First().Value);
+			FieldLoader.Load(handshake, MiniYaml.FromString(data).First().Value);
 			return handshake;
 		}

 		public string Serialize()
 		{
-			var data = new List<MiniYamlNode> { new("Handshake", FieldSaver.Save(this)) };
+			var data = new List<MiniYamlNode> { new MiniYamlNode("Handshake", FieldSaver.Save(this)) };
 			return data.WriteToString();
 		}
 	}
@@ -51,14 +51,14 @@ namespace OpenRA.Network
 		[FieldLoader.Ignore]
 		public Session.Client Client;

-		public static HandshakeResponse Deserialize(string data, string name)
+		public static HandshakeResponse Deserialize(string data)
 		{
 			var handshake = new HandshakeResponse
 			{
 				Client = new Session.Client()
 			};

-			var ys = MiniYaml.FromString(data, name);
+			var ys = MiniYaml.FromString(data);
 			foreach (var y in ys)
 			{
 				switch (y.Key)
@@ -79,9 +79,9 @@ namespace OpenRA.Network
 		{
 			var data = new List<MiniYamlNode>
 			{
-				new("Handshake", null,
+				new MiniYamlNode("Handshake", null,
 					new[] { "Mod", "Version", "Password", "Fingerprint", "AuthSignature", "OrdersProtocol" }.Select(p => FieldSaver.SaveField(this, p)).ToList()),
-				new("Client", FieldSaver.Save(Client))
+				new MiniYamlNode("Client", FieldSaver.Save(Client))
 			};

 			return data.WriteToString();
--- a/OpenRA.Game/Network/LocalizedMessage.cs
+++ b/OpenRA.Game/Network/LocalizedMessage.cs
@@ -9,8 +9,10 @@
 */
 #endregion

+using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text.RegularExpressions;
 using Linguini.Shared.Types.Bundle;

 namespace OpenRA.Network
@@ -40,7 +42,7 @@ namespace OpenRA.Network
 		{
 			switch (value.ToFluentType())
 			{
-				case FluentNumber:
+				case FluentNumber _:
 					return FluentArgumentType.Number;
 				default:
 					return FluentArgumentType.String;
@@ -55,51 +57,61 @@ namespace OpenRA.Network
 		public readonly string Key = string.Empty;

 		[FieldLoader.LoadUsing(nameof(LoadArguments))]
-		public readonly Dictionary<string, object> Arguments;
+		public readonly FluentArgument[] Arguments = Array.Empty<FluentArgument>();
+
+		public string TranslatedText { get; }

 		static object LoadArguments(MiniYaml yaml)
 		{
-			var arguments = new Dictionary<string, object>();
-			var argumentsNode = yaml.NodeWithKeyOrDefault("Arguments");
+			var arguments = new List<FluentArgument>();
+			var argumentsNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Arguments");
 			if (argumentsNode != null)
 			{
-				foreach (var argumentNode in argumentsNode.Value.Nodes)
-				{
-					var argument = FieldLoader.Load<FluentArgument>(argumentNode.Value);
-					if (argument.Type == FluentArgument.FluentArgumentType.Number)
-					{
-						if (!double.TryParse(argument.Value, out var number))
-							Log.Write("debug", $"Failed to parse {argument.Value}");
-
-						arguments.Add(argument.Key, number);
-					}
-					else
-						arguments.Add(argument.Key, argument.Value);
-				}
+				var regex = new Regex(@"Argument@\d+");
+				foreach (var argument in argumentsNode.Value.Nodes)
+					if (regex.IsMatch(argument.Key))
+						arguments.Add(FieldLoader.Load<FluentArgument>(argument.Value));
 			}

-			return arguments;
+			return arguments.ToArray();
 		}

-		public LocalizedMessage(MiniYaml yaml)
+		public LocalizedMessage(ModData modData, MiniYaml yaml)
 		{
 			// Let the FieldLoader do the dirty work of loading the public fields.
 			FieldLoader.Load(this, yaml);
+
+			var argumentDictionary = new Dictionary<string, object>();
+			foreach (var argument in Arguments)
+			{
+				if (argument.Type == FluentArgument.FluentArgumentType.Number)
+				{
+					if (!double.TryParse(argument.Value, out var number))
+						Log.Write("debug", $"Failed to parse {argument.Value}");
+
+					argumentDictionary.Add(argument.Key, number);
+				}
+				else
+					argumentDictionary.Add(argument.Key, argument.Value);
+			}
+
+			TranslatedText = modData.Translation.GetString(Key, argumentDictionary);
 		}

 		public static string Serialize(string key, Dictionary<string, object> arguments = null)
 		{
 			var root = new List<MiniYamlNode>
 			{
-				new("Protocol", ProtocolVersion.ToStringInvariant()),
-				new("Key", key)
+				new MiniYamlNode("Protocol", ProtocolVersion.ToString()),
+				new MiniYamlNode("Key", key)
 			};

 			if (arguments != null)
 			{
-				var argumentsNode = new MiniYaml("", arguments
-					.Select(a => new FluentArgument(a.Key, a.Value))
-					.Select((argument, i) => new MiniYamlNode("Argument@" + i, FieldSaver.Save(argument))));
+				var argumentsNode = new MiniYaml("");
+				var i = 0;
+				foreach (var argument in arguments.Select(a => new FluentArgument(a.Key, a.Value)))
+					argumentsNode.Nodes.Add(new MiniYamlNode("Argument@" + i++, FieldSaver.Save(argument)));

 				root.Add(new MiniYamlNode("Arguments", argumentsNode));
 			}
--- a/OpenRA.Game/Network/Nat.cs
+++ b/OpenRA.Game/Network/Nat.cs
@@ -17,7 +17,7 @@ namespace OpenRA.Network
 {
 	public enum NatStatus { Enabled, Disabled, NotSupported }

-	public static class Nat
+	public class Nat
 	{
 		public static NatStatus Status => NatUtility.IsSearching ? natDevice != null ? NatStatus.Enabled : NatStatus.NotSupported : NatStatus.Disabled;

@@ -39,7 +39,7 @@ namespace OpenRA.Network
 			initialized = true;
 		}

-		static readonly SemaphoreSlim Locker = new(1, 1);
+		static readonly SemaphoreSlim Locker = new SemaphoreSlim(1, 1);

 		static async void DeviceFound(object sender, DeviceEventArgs args)
 		{
@@ -49,8 +49,8 @@ namespace OpenRA.Network
 				// Only interact with one at a time. Some support both UPnP and NAT-PMP.
 				natDevice = args.Device;

-				Log.Write("nat", $"Device found: {natDevice.DeviceEndpoint}");
-				Log.Write("nat", $"Type: {natDevice.NatProtocol}");
+				Log.Write("nat", "Device found: {0}", natDevice.DeviceEndpoint);
+				Log.Write("nat", "Type: {0}", natDevice.NatProtocol);
 			}
 			finally
 			{
--- a/OpenRA.Game/Network/Order.cs
+++ b/OpenRA.Game/Network/Order.cs
@@ -156,18 +156,7 @@ namespace OpenRA
 									else
 									{
 										var pos = new WPos(r.ReadInt32(), r.ReadInt32(), r.ReadInt32());
-
-										var numberOfTerrainPositions = r.ReadInt16();
-										if (numberOfTerrainPositions == -1)
-											target = Target.FromPos(pos);
-										else
-										{
-											var terrainPositions = new WPos[numberOfTerrainPositions];
-											for (var i = 0; i < numberOfTerrainPositions; i++)
-												terrainPositions[i] = new WPos(r.ReadInt32(), r.ReadInt32(), r.ReadInt32());
-
-											target = Target.FromSerializedTerrainPosition(pos, terrainPositions);
-										}
+										target = Target.FromPos(pos);
 									}

 									break;
@@ -220,7 +209,7 @@ namespace OpenRA

 					default:
 					{
-						Log.Write("debug", $"Received unknown order with type {type}");
+						Log.Write("debug", "Received unknown order with type {0}", type);
 						return null;
 					}
 				}
@@ -228,7 +217,7 @@ namespace OpenRA
 			catch (Exception e)
 			{
 				Log.Write("debug", "Caught exception while processing order");
-				Log.Write("debug", e);
+				Log.Write("debug", e.ToString());

 				// HACK: this can hopefully go away in the future
 				TextNotificationsManager.Debug("Ignoring malformed order that would have crashed the game");
@@ -340,8 +329,6 @@ namespace OpenRA

 				case OrderType.Fields:
 				{
-					var targetState = Target.SerializableState;
-
 					var fields = OrderFields.None;
 					if (Subject != null)
 						fields |= OrderFields.Subject;
@@ -352,7 +339,7 @@ namespace OpenRA
 					if (ExtraData != 0)
 						fields |= OrderFields.ExtraData;

-					if (targetState.Type != TargetType.Invalid)
+					if (Target.SerializableType != TargetType.Invalid)
 						fields |= OrderFields.Target;

 					if (Queued)
@@ -367,7 +354,7 @@ namespace OpenRA
 					if (ExtraLocation != CPos.Zero)
 						fields |= OrderFields.ExtraLocation;

-					if (targetState.Cell != null)
+					if (Target.SerializableCell != null)
 						fields |= OrderFields.TargetIsCell;

 					w.Write((short)fields);
@@ -377,12 +364,12 @@ namespace OpenRA

 					if (fields.HasField(OrderFields.Target))
 					{
-						w.Write((byte)targetState.Type);
-						switch (targetState.Type)
+						w.Write((byte)Target.SerializableType);
+						switch (Target.SerializableType)
 						{
 							case TargetType.Actor:
-								w.Write(UIntFromActor(targetState.Actor));
-								w.Write(targetState.Generation);
+								w.Write(UIntFromActor(Target.SerializableActor));
+								w.Write(Target.SerializableGeneration);
 								break;
 							case TargetType.FrozenActor:
 								w.Write(Target.FrozenActor.Viewer.PlayerActor.ActorID);
@@ -391,29 +378,14 @@ namespace OpenRA
 							case TargetType.Terrain:
 								if (fields.HasField(OrderFields.TargetIsCell))
 								{
-									w.Write(targetState.Cell.Value.Bits);
-									w.Write((byte)targetState.SubCell);
+									w.Write(Target.SerializableCell.Value.Bits);
+									w.Write((byte)Target.SerializableSubCell);
 								}
 								else
 								{
-									w.Write(targetState.Pos.X);
-									w.Write(targetState.Pos.Y);
-									w.Write(targetState.Pos.Z);
-
-									// Don't send extra data over the network that will be restored by the Target ctor
-									var terrainPositions = targetState.TerrainPositions.Length;
-									if (terrainPositions == 1 && targetState.TerrainPositions[0] == targetState.Pos)
-										w.Write((short)-1);
-									else
-									{
-										w.Write((short)terrainPositions);
-										foreach (var position in targetState.TerrainPositions)
-										{
-											w.Write(position.X);
-											w.Write(position.Y);
-											w.Write(position.Z);
-										}
-									}
+									w.Write(Target.SerializablePos.X);
+									w.Write(Target.SerializablePos.Y);
+									w.Write(Target.SerializablePos.Z);
 								}

 								break;
--- a/Show More
+++ b/Show More