diff --git a/OpenRA.Game/Actor.cs b/OpenRA.Game/Actor.cs
index 1dbc155022..07f2478299 100644
--- a/OpenRA.Game/Actor.cs
+++ b/OpenRA.Game/Actor.cs
@@ -22,14 +22,36 @@ using OpenRA.Traits;
 
 namespace OpenRA
 {
-	public class Actor : IScriptBindable, IScriptNotifyBind, ILuaTableBinding, ILuaEqualityBinding, ILuaToStringBinding, IEquatable<Actor>
+	public interface IActor
 	{
-		public readonly ActorInfo Info;
+		ActorInfo Info { get; }
+		IWorld World { get; }
+		uint ActorID { get; }
+		Player Owner { get; set; }
+
+		T TraitOrDefault<T>();
+		T Trait<T>();
+		IEnumerable<T> TraitsImplementing<T>();
+
+		T TraitInfo<T>();
+
+		IEnumerable<IRenderable> Render(WorldRenderer wr);
+	}
+
+	public class Actor : IScriptBindable, IScriptNotifyBind, ILuaTableBinding, ILuaEqualityBinding, ILuaToStringBinding, IEquatable<Actor>, IActor
+	{
+		public ActorInfo Info { get; private set; }
 		public readonly World World;
-		public readonly uint ActorID;
+
+		IWorld IActor.World
+		{
+			get { return World; }
+		}
+
+		public uint ActorID { get; private set; }
 
 		[Sync]
-		public Player Owner;
+		public Player Owner { get; set; }
 
 		public bool IsInWorld { get; internal set; }
 		public bool Destroyed { get; private set; }
@@ -202,6 +224,11 @@ namespace OpenRA
 			return World.TraitDict.WithInterface<T>(this);
 		}
 
+		public T TraitInfo<T>()
+		{
+			return Info.Traits.Get<T>();
+		}
+
 		public bool HasTrait<T>()
 		{
 			return World.TraitDict.Contains<T>(this);
@@ -235,7 +262,7 @@ namespace OpenRA
 		{
 			World.AddFrameEndTask(w =>
 			{
-				if (this.Destroyed)
+				if (Destroyed)
 					return;
 
 				var oldOwner = Owner;
diff --git a/OpenRA.Game/CacheStorage.cs b/OpenRA.Game/CacheStorage.cs
new file mode 100644
index 0000000000..e5216a9639
--- /dev/null
+++ b/OpenRA.Game/CacheStorage.cs
@@ -0,0 +1,19 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2015 The OpenRA Developers (see AUTHORS)
+ * 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. For more information,
+ * see COPYING.
+ */
+#endregion
+
+namespace OpenRA
+{
+	public interface ICacheStorage<T>
+	{
+		void Remove(string key);
+		void Store(string key, T data);
+		T Retrieve(string key);
+	}
+}
\ No newline at end of file
diff --git a/OpenRA.Game/LogProxy.cs b/OpenRA.Game/LogProxy.cs
new file mode 100644
index 0000000000..0f313470aa
--- /dev/null
+++ b/OpenRA.Game/LogProxy.cs
@@ -0,0 +1,25 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2015 The OpenRA Developers (see AUTHORS)
+ * 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. 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);
+		}
+	}
+}
diff --git a/OpenRA.Game/Map/Map.cs b/OpenRA.Game/Map/Map.cs
index f1b6dc4fbd..801ad43542 100644
--- a/OpenRA.Game/Map/Map.cs
+++ b/OpenRA.Game/Map/Map.cs
@@ -111,15 +111,33 @@ namespace OpenRA
 		MissionSelector = 4
 	}
 
-	public class Map
+	public interface IMap
+	{
+		TileShape TileShape { get; }
+
+		int2 MapSize { get; set; }
+		bool Contains(CPos cell);
+		CPos CellContaining(WPos pos);
+		WVec OffsetOfSubCell(SubCell subCell);
+		IEnumerable<CPos> FindTilesInCircle(CPos center, int maxRange);
+		WPos CenterOfCell(CPos cell);
+	}
+
+	public class Map : IMap
 	{
 		public const int MaxTilesInCircleRange = 50;
 		public readonly TileShape TileShape;
+		TileShape IMap.TileShape
+		{
+			get { return TileShape; }
+		}
+
 		[FieldLoader.Ignore]
 		public readonly WVec[] SubCellOffsets;
 		public readonly SubCell DefaultSubCell;
 		public readonly SubCell LastSubCell;
-		[FieldLoader.Ignore] public IFolder Container;
+		[FieldLoader.Ignore]
+		public IFolder Container;
 		public string Path { get; private set; }
 
 		// Yaml map data
@@ -165,41 +183,65 @@ namespace OpenRA
 			return videos;
 		}
 
-		[FieldLoader.Ignore] public Lazy<Dictionary<string, ActorReference>> Actors;
+		[FieldLoader.Ignore]
+		public Lazy<Dictionary<string, ActorReference>> Actors;
 
 		public int PlayerCount { get { return Players.Count(p => p.Value.Playable); } }
 
 		public Rectangle Bounds;
 
 		// Yaml map data
-		[FieldLoader.Ignore] public Dictionary<string, PlayerReference> Players = new Dictionary<string, PlayerReference>();
-		[FieldLoader.Ignore] public Lazy<List<SmudgeReference>> Smudges;
+		[FieldLoader.Ignore]
+		public Dictionary<string, PlayerReference> Players = new Dictionary<string, PlayerReference>();
+		[FieldLoader.Ignore]
+		public Lazy<List<SmudgeReference>> Smudges;
 
-		[FieldLoader.Ignore] public List<MiniYamlNode> RuleDefinitions = new List<MiniYamlNode>();
-		[FieldLoader.Ignore] public List<MiniYamlNode> SequenceDefinitions = new List<MiniYamlNode>();
-		[FieldLoader.Ignore] public List<MiniYamlNode> VoxelSequenceDefinitions = new List<MiniYamlNode>();
-		[FieldLoader.Ignore] public List<MiniYamlNode> WeaponDefinitions = new List<MiniYamlNode>();
-		[FieldLoader.Ignore] public List<MiniYamlNode> VoiceDefinitions = new List<MiniYamlNode>();
-		[FieldLoader.Ignore] public List<MiniYamlNode> NotificationDefinitions = new List<MiniYamlNode>();
-		[FieldLoader.Ignore] public List<MiniYamlNode> TranslationDefinitions = new List<MiniYamlNode>();
+		[FieldLoader.Ignore]
+		public List<MiniYamlNode> RuleDefinitions = new List<MiniYamlNode>();
+		[FieldLoader.Ignore]
+		public List<MiniYamlNode> SequenceDefinitions = new List<MiniYamlNode>();
+		[FieldLoader.Ignore]
+		public List<MiniYamlNode> VoxelSequenceDefinitions = new List<MiniYamlNode>();
+		[FieldLoader.Ignore]
+		public List<MiniYamlNode> WeaponDefinitions = new List<MiniYamlNode>();
+		[FieldLoader.Ignore]
+		public List<MiniYamlNode> VoiceDefinitions = new List<MiniYamlNode>();
+		[FieldLoader.Ignore]
+		public List<MiniYamlNode> NotificationDefinitions = new List<MiniYamlNode>();
+		[FieldLoader.Ignore]
+		public List<MiniYamlNode> TranslationDefinitions = new List<MiniYamlNode>();
 
 		// Binary map data
-		[FieldLoader.Ignore] public byte TileFormat = 2;
+		[FieldLoader.Ignore]
+		public byte TileFormat = 2;
 
 		public int2 MapSize;
 
-		[FieldLoader.Ignore] public Lazy<CellLayer<TerrainTile>> MapTiles;
-		[FieldLoader.Ignore] public Lazy<CellLayer<ResourceTile>> MapResources;
-		[FieldLoader.Ignore] public Lazy<CellLayer<byte>> MapHeight;
+		int2 IMap.MapSize
+		{
+			get { return MapSize; }
+			set { MapSize = value; }
+		}
 
-		[FieldLoader.Ignore] public CellLayer<byte> CustomTerrain;
+		[FieldLoader.Ignore]
+		public Lazy<CellLayer<TerrainTile>> MapTiles;
+		[FieldLoader.Ignore]
+		public Lazy<CellLayer<ResourceTile>> MapResources;
+		[FieldLoader.Ignore]
+		public Lazy<CellLayer<byte>> MapHeight;
 
-		[FieldLoader.Ignore] Lazy<TileSet> cachedTileSet;
-		[FieldLoader.Ignore] Lazy<Ruleset> rules;
+		[FieldLoader.Ignore]
+		public CellLayer<byte> CustomTerrain;
+
+		[FieldLoader.Ignore]
+		Lazy<TileSet> cachedTileSet;
+		[FieldLoader.Ignore]
+		Lazy<Ruleset> rules;
 		public Ruleset Rules { get { return rules != null ? rules.Value : null; } }
 		public SequenceProvider SequenceProvider { get { return Rules.Sequences[Tileset]; } }
 
-		[FieldLoader.Ignore] public CellRegion Cells;
+		[FieldLoader.Ignore]
+		public CellRegion Cells;
 
 		public static Map FromTileset(TileSet tileset)
 		{
diff --git a/OpenRA.Game/OpenRA.Game.csproj b/OpenRA.Game/OpenRA.Game.csproj
index db244831f3..af61ef4bf9 100644
--- a/OpenRA.Game/OpenRA.Game.csproj
+++ b/OpenRA.Game/OpenRA.Game.csproj
@@ -84,6 +84,8 @@
     <Compile Include="Activities\Activity.cs" />
     <Compile Include="Activities\CallFunc.cs" />
     <Compile Include="Actor.cs" />
+    <Compile Include="CacheStorage.cs" />
+    <Compile Include="LogProxy.cs" />
     <Compile Include="MPos.cs" />
     <Compile Include="GameRules\Warhead.cs" />
     <Compile Include="Graphics\QuadRenderer.cs" />
diff --git a/OpenRA.Game/World.cs b/OpenRA.Game/World.cs
index 8467ba2439..de23db10ce 100644
--- a/OpenRA.Game/World.cs
+++ b/OpenRA.Game/World.cs
@@ -24,7 +24,15 @@ namespace OpenRA
 {
 	public enum WorldType { Regular, Shellmap }
 
-	public class World
+	public interface IWorld
+	{
+		IActor WorldActor { get; }
+		int WorldTick { get; }
+		IMap Map { get; }
+		TileSet TileSet { get; }
+	}
+
+	public class World : IWorld
 	{
 		class ActorIDComparer : IComparer<Actor>
 		{
@@ -113,9 +121,13 @@ namespace OpenRA
 			RenderPlayer = LocalPlayer;
 		}
 
-		public readonly Actor WorldActor;
-		public readonly Map Map;
-		public readonly TileSet TileSet;
+		public Actor WorldActor { get; private set; }
+		IActor IWorld.WorldActor { get { return WorldActor; } }
+
+		public Map Map { get; private set; }
+		IMap IWorld.Map { get { return Map; } }
+
+		public TileSet TileSet { get; private set; }
 		public readonly ActorMap ActorMap;
 		public readonly ScreenMap ScreenMap;
 		public readonly WorldType Type;
diff --git a/OpenRA.Mods.Common/Traits/Mobile.cs b/OpenRA.Mods.Common/Traits/Mobile.cs
index 4e3cc08759..89bd615dd7 100644
--- a/OpenRA.Mods.Common/Traits/Mobile.cs
+++ b/OpenRA.Mods.Common/Traits/Mobile.cs
@@ -29,8 +29,17 @@ namespace OpenRA.Mods.Common.Traits
 		All = TransientActors | BlockedByMovers
 	}
 
+	public interface IMobileInfo
+	{
+		int MovementCostForCell(World world, CPos cell);
+		bool CanEnterCell(World world, Actor self, CPos cell, out int movementCost, Actor ignoreActor = null, CellConditions check = CellConditions.All);
+		bool CanEnterCell(World world, Actor self, CPos cell, Actor ignoreActor = null, CellConditions check = CellConditions.All);
+
+		int GetMovementClass(TileSet tileset);
+	}
+
 	[Desc("Unit is able to move.")]
-	public class MobileInfo : ITraitInfo, IOccupySpaceInfo, IFacingInfo, IMoveInfo, UsesInit<FacingInit>, UsesInit<LocationInit>, UsesInit<SubCellInit>
+	public class MobileInfo : ITraitInfo, IOccupySpaceInfo, IFacingInfo, IMoveInfo, UsesInit<FacingInit>, UsesInit<LocationInit>, UsesInit<SubCellInit>, IMobileInfo
 	{
 		[FieldLoader.LoadUsing("LoadSpeeds")]
 		[Desc("Set Water: 0 for ground units and lower the value on rough terrain.")]
@@ -165,11 +174,61 @@ namespace OpenRA.Mods.Common.Traits
 			return true;
 		}
 
+		public int TileSetMovementHash(TileSet tileSet)
+		{
+			var terrainInfos = TilesetTerrainInfo[tileSet];
+
+			// Compute and return the hash using aggregate
+			return terrainInfos.Aggregate(terrainInfos.Length,
+				(current, terrainInfo) => unchecked(current * 31 + terrainInfo.Cost));
+		}
+
 		public bool CanEnterCell(World world, Actor self, CPos cell, Actor ignoreActor = null, CellConditions check = CellConditions.All)
 		{
 			if (MovementCostForCell(world, cell) == int.MaxValue)
 				return false;
 
+			return CanMoveFreelyInto(world, self, cell, ignoreActor, check);
+		}
+
+		// Determines whether the actor is blocked by other Actors
+		public bool CanMoveFreelyInto(World world, Actor self, CPos cell, Actor ignoreActor, CellConditions check)
+		{
+			if (SharesCell && world.ActorMap.HasFreeSubCell(cell))
+				return true;
+
+			if (check.HasFlag(CellConditions.TransientActors))
+			{
+				var canIgnoreMovingAllies = self != null && !check.HasFlag(CellConditions.BlockedByMovers);
+				var needsCellExclusively = self == null || Crushes == null || !Crushes.Any();
+				foreach (var a in world.ActorMap.GetUnitsAt(cell))
+				{
+					if (a == ignoreActor)
+						continue;
+
+					// Neutral/enemy units are blockers. Allied units that are moving are not blockers.
+					if (canIgnoreMovingAllies && self.Owner.Stances[a.Owner] == Stance.Ally && IsMovingInMyDirection(self, a)) continue;
+
+					// Non-sharable unit can enter a cell with shareable units only if it can crush all of them.
+					if (needsCellExclusively)
+						return false;
+					var crushables = a.TraitsImplementing<ICrushable>();
+					if (!crushables.Any())
+						return false;
+					foreach (var crushable in crushables)
+						if (!crushable.CrushableBy(Crushes, self.Owner))
+							return false;
+				}
+			}
+
+			return true;
+		}
+
+		public bool CanEnterCell(World world, Actor self, CPos cell, out int movementCost, Actor ignoreActor = null, CellConditions check = CellConditions.All)
+		{
+			if ((movementCost = MovementCostForCell(world, cell)) == int.MaxValue)
+				return false;
+
 			if (SharesCell && world.ActorMap.HasFreeSubCell(cell))
 				return true;
 
@@ -506,6 +565,11 @@ namespace OpenRA.Mods.Common.Traits
 			return Info.CanEnterCell(self.World, self, cell, ignoreActor, checkTransientActors ? CellConditions.All : CellConditions.BlockedByMovers);
 		}
 
+		public bool CanMoveFreely(CPos cell, Actor ignoreActor = null, bool checkTransientActors = true)
+		{
+			return Info.CanMoveFreelyInto(self.World, self, cell, ignoreActor, checkTransientActors ? CellConditions.All : CellConditions.BlockedByMovers);
+		}
+
 		public void EnteringCell(Actor self)
 		{
 			var crushables = self.World.ActorMap.GetUnitsAt(ToCell).Where(a => a != self)