diff --git a/OpenRa.Game/Controller.cs b/OpenRa.Game/Controller.cs
index a7f649ef5c..74d81d81f2 100644
--- a/OpenRa.Game/Controller.cs
+++ b/OpenRa.Game/Controller.cs
@@ -128,69 +128,5 @@ namespace OpenRa
 					throw new InvalidOperationException( "Desync in Controller.ChooseCursor" );
 			}
 		}
-
-		Cache<int, List<Actor>> controlGroups = new Cache<int, List<Actor>>(_ => new List<Actor>());
-
-		public void DoControlGroup(World world, int group, Modifiers mods)
-		{
-			if (mods.HasModifier(Modifiers.Ctrl))
-			{
-				if (!selection.Actors.Any())
-					return;
-
-				controlGroups[group].Clear();
-
-				for (var i = 0; i < 10; i++)	/* all control groups */
-					controlGroups[i].RemoveAll(a => selection.Actors.Contains(a));
-
-				controlGroups[group].AddRange(selection.Actors);
-				return;
-			}
-
-			if (mods.HasModifier(Modifiers.Alt))
-			{
-				Game.viewport.Center(controlGroups[group]);
-				return;
-			}
-
-			selection.Combine(world, controlGroups[group], 
-				mods.HasModifier(Modifiers.Shift), false);
-		}
-
-		public int? GetControlGroupForActor(Actor a)
-		{
-			return controlGroups.Where(g => g.Value.Contains(a))
-				.Select(g => (int?)g.Key)
-				.FirstOrDefault();
-		}
-	}
-
-	public class Selection
-	{
-		List<Actor> actors = new List<Actor>();
-
-		public void Combine(World world, IEnumerable<Actor> newSelection, bool isCombine, bool isClick)
-		{
-			var oldSelection = actors.AsEnumerable();
-
-			if (isClick)
-			{
-				var adjNewSelection = newSelection.Take(1);	/* todo: select BEST, not FIRST */
-				actors = (isCombine ? oldSelection.SymmetricDifference(adjNewSelection) : adjNewSelection).ToList();
-			}
-			else
-				actors = (isCombine ? oldSelection.Union(newSelection) : newSelection).ToList();
-
-			var voicedUnit = actors.FirstOrDefault(a => a.traits.Contains<Unit>() && a.Owner == world.LocalPlayer);
-			Sound.PlayVoice("Select", voicedUnit);
-		}
-
-		public IEnumerable<Actor> Actors { get { return actors; } }
-		public void Clear() { actors = new List<Actor>(); }
-
-		public void Tick(World world)
-		{
-			actors.RemoveAll(a => !a.IsInWorld);
-		}
 	}
 }
diff --git a/OpenRa.Game/Game.cs b/OpenRa.Game/Game.cs
index a669919d12..dbc8949625 100644
--- a/OpenRa.Game/Game.cs
+++ b/OpenRa.Game/Game.cs
@@ -292,7 +292,8 @@ namespace OpenRa
 
 			if( !Game.chat.isChatting )
 				if( e.KeyCode >= Keys.D0 && e.KeyCode <= Keys.D9 )
-					Game.controller.DoControlGroup( world, (int)e.KeyCode - (int)Keys.D0, (Modifiers)(int)e.Modifiers );
+					Game.controller.selection.DoControlGroup( world, 
+						(int)e.KeyCode - (int)Keys.D0, (Modifiers)(int)e.Modifiers );
 
 			if( sync != Game.world.SyncHash() )
 				throw new InvalidOperationException( "Desync in OnKeyDown" );
diff --git a/OpenRa.Game/Graphics/WorldRenderer.cs b/OpenRa.Game/Graphics/WorldRenderer.cs
index 60fc661407..10d180f94c 100644
--- a/OpenRa.Game/Graphics/WorldRenderer.cs
+++ b/OpenRa.Game/Graphics/WorldRenderer.cs
@@ -234,7 +234,7 @@ namespace OpenRa.Graphics
 
 		void DrawControlGroup(Actor selectedUnit, float2 basePosition)
 		{
-			var group = Game.controller.GetControlGroupForActor(selectedUnit);
+			var group = Game.controller.selection.GetControlGroupForActor(selectedUnit);
 			if (group == null) return;
 
 			var pipImages = new Animation("pips");
diff --git a/OpenRa.Game/OpenRa.Game.csproj b/OpenRa.Game/OpenRa.Game.csproj
index 646de1c6ea..0f5e772675 100644
--- a/OpenRa.Game/OpenRa.Game.csproj
+++ b/OpenRa.Game/OpenRa.Game.csproj
@@ -111,6 +111,7 @@
     <Compile Include="Ore.cs" />
     <Compile Include="PackageDownloader.cs" />
     <Compile Include="PathSearch.cs" />
+    <Compile Include="Selection.cs" />
     <Compile Include="Shroud.cs" />
     <Compile Include="Smudge.cs" />
     <Compile Include="Sound.cs" />
diff --git a/OpenRa.Game/Selection.cs b/OpenRa.Game/Selection.cs
new file mode 100644
index 0000000000..61e441d386
--- /dev/null
+++ b/OpenRa.Game/Selection.cs
@@ -0,0 +1,73 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using OpenRa.Traits;
+using IjwFramework.Collections;
+
+namespace OpenRa
+{
+	public class Selection
+	{
+		List<Actor> actors = new List<Actor>();
+
+		public void Combine(World world, IEnumerable<Actor> newSelection, bool isCombine, bool isClick)
+		{
+			var oldSelection = actors.AsEnumerable();
+
+			if (isClick)
+			{
+				var adjNewSelection = newSelection.Take(1);	/* todo: select BEST, not FIRST */
+				actors = (isCombine ? oldSelection.SymmetricDifference(adjNewSelection) : adjNewSelection).ToList();
+			}
+			else
+				actors = (isCombine ? oldSelection.Union(newSelection) : newSelection).ToList();
+
+			var voicedUnit = actors.FirstOrDefault(a => a.traits.Contains<Unit>() && a.Owner == world.LocalPlayer);
+			Sound.PlayVoice("Select", voicedUnit);
+		}
+
+		public IEnumerable<Actor> Actors { get { return actors; } }
+		public void Clear() { actors = new List<Actor>(); }
+
+		public void Tick(World world)
+		{
+			actors.RemoveAll(a => !a.IsInWorld);
+		}
+
+		Cache<int, List<Actor>> controlGroups = new Cache<int, List<Actor>>(_ => new List<Actor>());
+
+		public void DoControlGroup(World world, int group, Modifiers mods)
+		{
+			if (mods.HasModifier(Modifiers.Ctrl))
+			{
+				if (actors.Count == 0)
+					return;
+
+				controlGroups[group].Clear();
+
+				for (var i = 0; i < 10; i++)	/* all control groups */
+					controlGroups[i].RemoveAll(a => actors.Contains(a));
+
+				controlGroups[group].AddRange(actors);
+				return;
+			}
+
+			if (mods.HasModifier(Modifiers.Alt))
+			{
+				Game.viewport.Center(controlGroups[group]);
+				return;
+			}
+
+			Combine(world, controlGroups[group],
+				mods.HasModifier(Modifiers.Shift), false);
+		}
+
+		public int? GetControlGroupForActor(Actor a)
+		{
+			return controlGroups.Where(g => g.Value.Contains(a))
+				.Select(g => (int?)g.Key)
+				.FirstOrDefault();
+		}
+	}
+}