diff --git a/OpenRA.Game/GameRules/RulesetCache.cs b/OpenRA.Game/GameRules/RulesetCache.cs
index e817689b3c..b308b18a8e 100644
--- a/OpenRA.Game/GameRules/RulesetCache.cs
+++ b/OpenRA.Game/GameRules/RulesetCache.cs
@@ -21,8 +21,6 @@ namespace OpenRA
 {
 	public sealed class RulesetCache
 	{
-		static readonly string[] NoMapRules = new string[0];
-
 		readonly ModData modData;
 
 		readonly Dictionary<string, ActorInfo> actorCache = new Dictionary<string, ActorInfo>();
@@ -44,11 +42,13 @@ namespace OpenRA
 			this.modData = modData;
 		}
 
-		/// <summary>
-		/// Cache and return the Ruleset for a given map.
-		/// If a map isn't specified then return the default mod Ruleset.
-		/// </summary>
-		public Ruleset Load(IReadOnlyFileSystem fileSystem, Map map = null)
+		public Ruleset Load(IReadOnlyFileSystem fileSystem,
+			MiniYaml additionalRules,
+			MiniYaml additionalWeapons,
+			MiniYaml additionalVoices,
+			MiniYaml additionalNotifications,
+			MiniYaml additionalMusic,
+			MiniYaml additionalSequences)
 		{
 			var m = modData.Manifest;
 
@@ -60,46 +60,58 @@ namespace OpenRA
 			Dictionary<string, TileSet> tileSets;
 
 			using (new PerfTimer("Actors"))
-				actors = LoadYamlRules(fileSystem, actorCache, m.Rules,
-					map != null ? map.RuleDefinitions : NoMapRules,
+				actors = LoadYamlRules(fileSystem, actorCache, m.Rules, additionalRules,
 					k => new ActorInfo(Game.ModData.ObjectCreator, k.Key.ToLowerInvariant(), k.Value));
 
 			using (new PerfTimer("Weapons"))
-				weapons = LoadYamlRules(fileSystem, weaponCache, m.Weapons,
-					map != null ? map.WeaponDefinitions : NoMapRules,
+				weapons = LoadYamlRules(fileSystem, weaponCache, m.Weapons, additionalWeapons,
 					k => new WeaponInfo(k.Key.ToLowerInvariant(), k.Value));
 
 			using (new PerfTimer("Voices"))
-				voices = LoadYamlRules(fileSystem, voiceCache, m.Voices,
-					map != null ? map.VoiceDefinitions : NoMapRules,
+				voices = LoadYamlRules(fileSystem, voiceCache, m.Voices, additionalVoices,
 					k => new SoundInfo(k.Value));
 
 			using (new PerfTimer("Notifications"))
-				notifications = LoadYamlRules(fileSystem, notificationCache, m.Notifications,
-					map != null ? map.NotificationDefinitions : NoMapRules,
+				notifications = LoadYamlRules(fileSystem, notificationCache, m.Notifications, additionalNotifications,
 					k => new SoundInfo(k.Value));
 
 			using (new PerfTimer("Music"))
-				music = LoadYamlRules(fileSystem, musicCache, m.Music,
-					map != null ? map.MusicDefinitions : NoMapRules,
+				music = LoadYamlRules(fileSystem, musicCache, m.Music, additionalMusic,
 					k => new MusicInfo(k.Key, k.Value));
 
 			using (new PerfTimer("TileSets"))
 				tileSets = LoadTileSets(fileSystem, tileSetCache, m.TileSets);
 
 			// TODO: only initialize, and then cache, the provider for the given map
-			var sequences = tileSets.ToDictionary(t => t.Key, t => new SequenceProvider(fileSystem, modData, t.Value, map));
+			var sequences = tileSets.ToDictionary(t => t.Key, t => new SequenceProvider(fileSystem, modData, t.Value, additionalSequences));
 			return new Ruleset(actors, weapons, voices, notifications, music, tileSets, sequences);
 		}
 
+		/// <summary>
+		/// Cache and return the Ruleset for a given map.
+		/// If a map isn't specified then return the default mod Ruleset.
+		/// </summary>
+		public Ruleset Load(IReadOnlyFileSystem fileSystem, Map map = null)
+		{
+			return map != null ? Load(fileSystem, map.RuleDefinitions, map.WeaponDefinitions,
+				map.VoiceDefinitions, map.NotificationDefinitions, map.MusicDefinitions,
+				map.SequenceDefinitions) : Load(fileSystem, null, null, null, null, null, null);
+		}
+
 		Dictionary<string, T> LoadYamlRules<T>(IReadOnlyFileSystem fileSystem,
 			Dictionary<string, T> itemCache,
-			string[] files, string[] mapFiles,
+			IEnumerable<string> files, MiniYaml mapRules,
 			Func<MiniYamlNode, T> f)
 		{
 			RaiseProgress();
 
-			var inputKey = string.Concat(string.Join("|", files.Append(mapFiles)), "|");
+			if (mapRules != null && mapRules.Value != null)
+				files = files.Append(FieldLoader.GetValue<string[]>("value", mapRules.Value));
+
+			var inputKey = string.Join("|", files);
+			if (mapRules != null && mapRules.Nodes.Any())
+				inputKey += "|" + mapRules.Nodes.WriteToString();
+
 			Func<MiniYamlNode, T> wrap = wkv =>
 			{
 				var key = inputKey + wkv.Value.ToLines(wkv.Key).JoinWith("|");
@@ -114,8 +126,9 @@ namespace OpenRA
 				return t;
 			};
 
-			var tree = MiniYaml.Merge(files.Append(mapFiles).Select(s => MiniYaml.FromStream(fileSystem.Open(s))))
-				.ToDictionaryWithConflictLog(n => n.Key, n => n.Value, "LoadYamlRules", null, null);
+			var tree = MiniYaml.Load(fileSystem, files, mapRules).ToDictionaryWithConflictLog(
+				n => n.Key, n => n.Value, "LoadYamlRules", null, null);
+
 			RaiseProgress();
 
 			var itemSet = tree.ToDictionary(kv => kv.Key.ToLowerInvariant(), kv => wrap(new MiniYamlNode(kv.Key, kv.Value)));
diff --git a/OpenRA.Game/Graphics/SequenceProvider.cs b/OpenRA.Game/Graphics/SequenceProvider.cs
index 97a31f8899..654a4b411c 100644
--- a/OpenRA.Game/Graphics/SequenceProvider.cs
+++ b/OpenRA.Game/Graphics/SequenceProvider.cs
@@ -53,11 +53,16 @@ namespace OpenRA.Graphics
 
 		readonly Dictionary<string, UnitSequences> sequenceCache = new Dictionary<string, UnitSequences>();
 
-		public SequenceProvider(IReadOnlyFileSystem fileSystem, ModData modData, TileSet tileSet, Map map)
+		public SequenceProvider(IReadOnlyFileSystem fileSystem, ModData modData, TileSet tileSet, MiniYaml additionalSequences)
 		{
 			this.modData = modData;
 			this.tileSet = tileSet;
-			sequences = Exts.Lazy(() => LoadSequences(fileSystem, map));
+			sequences = Exts.Lazy(() =>
+			{
+				using (new Support.PerfTimer("LoadSequences"))
+					return Load(fileSystem, additionalSequences);
+			});
+
 			spriteCache = Exts.Lazy(() => new SpriteCache(fileSystem, modData.SpriteLoaders, new SheetBuilder(SheetType.Indexed)));
 		}
 
@@ -97,17 +102,9 @@ namespace OpenRA.Graphics
 			return unitSeq.Value.Keys;
 		}
 
-		public Sequences LoadSequences(IReadOnlyFileSystem fileSystem, Map map)
+		Sequences Load(IReadOnlyFileSystem fileSystem, MiniYaml additionalSequences)
 		{
-			using (new Support.PerfTimer("LoadSequences"))
-				return Load(fileSystem, map != null ? map.SequenceDefinitions : new string[0]);
-		}
-
-		Sequences Load(IReadOnlyFileSystem fileSystem, string[] mapSequences)
-		{
-			var nodes = MiniYaml.Merge(modData.Manifest.Sequences.Append(mapSequences)
-				.Select(s => MiniYaml.FromStream(fileSystem.Open(s))));
-
+			var nodes = MiniYaml.Load(fileSystem, modData.Manifest.Sequences, additionalSequences);
 			var items = new Dictionary<string, UnitSequences>();
 			foreach (var n in nodes)
 			{
diff --git a/OpenRA.Game/Graphics/VoxelProvider.cs b/OpenRA.Game/Graphics/VoxelProvider.cs
index 0f6aca848b..804fffbf2f 100644
--- a/OpenRA.Game/Graphics/VoxelProvider.cs
+++ b/OpenRA.Game/Graphics/VoxelProvider.cs
@@ -21,13 +21,9 @@ namespace OpenRA.Graphics
 	{
 		static Dictionary<string, Dictionary<string, Voxel>> units;
 
-		public static void Initialize(VoxelLoader loader, IReadOnlyFileSystem fileSystem, IEnumerable<string> voxelFiles)
+		public static void Initialize(VoxelLoader loader, IReadOnlyFileSystem fileSystem, List<MiniYamlNode> sequences)
 		{
 			units = new Dictionary<string, Dictionary<string, Voxel>>();
-
-			var sequences = MiniYaml.Merge(voxelFiles.Select(
-				s => MiniYaml.FromStream(fileSystem.Open(s))));
-
 			foreach (var s in sequences)
 				LoadVoxelsForUnit(loader, s.Key, s.Value);
 
diff --git a/OpenRA.Game/Map/Map.cs b/OpenRA.Game/Map/Map.cs
index 4add5c064d..a0bc1b02f3 100644
--- a/OpenRA.Game/Map/Map.cs
+++ b/OpenRA.Game/Map/Map.cs
@@ -141,14 +141,14 @@ namespace OpenRA
 		public Lazy<CPos[]> SpawnPoints;
 
 		// Yaml map data
-		[FieldLoader.Ignore] public readonly string[] RuleDefinitions = { };
-		[FieldLoader.Ignore] public readonly string[] SequenceDefinitions = { };
-		[FieldLoader.Ignore] public readonly string[] VoxelSequenceDefinitions = { };
-		[FieldLoader.Ignore] public readonly string[] WeaponDefinitions = { };
-		[FieldLoader.Ignore] public readonly string[] VoiceDefinitions = { };
-		[FieldLoader.Ignore] public readonly string[] MusicDefinitions = { };
-		[FieldLoader.Ignore] public readonly string[] NotificationDefinitions = { };
-		[FieldLoader.Ignore] public readonly string[] TranslationDefinitions = { };
+		[FieldLoader.Ignore] public readonly MiniYaml RuleDefinitions;
+		[FieldLoader.Ignore] public readonly MiniYaml SequenceDefinitions;
+		[FieldLoader.Ignore] public readonly MiniYaml VoxelSequenceDefinitions;
+		[FieldLoader.Ignore] public readonly MiniYaml WeaponDefinitions;
+		[FieldLoader.Ignore] public readonly MiniYaml VoiceDefinitions;
+		[FieldLoader.Ignore] public readonly MiniYaml MusicDefinitions;
+		[FieldLoader.Ignore] public readonly MiniYaml NotificationDefinitions;
+		[FieldLoader.Ignore] public readonly MiniYaml TranslationDefinitions;
 
 		[FieldLoader.Ignore] public List<MiniYamlNode> PlayerDefinitions = new List<MiniYamlNode>();
 		[FieldLoader.Ignore] public List<MiniYamlNode> ActorDefinitions = new List<MiniYamlNode>();
@@ -184,13 +184,6 @@ namespace OpenRA
 					throw new InvalidOperationException("Required file {0} not present in this map".F(filename));
 		}
 
-		void LoadFileList(MiniYaml yaml, string section, ref string[] files)
-		{
-			MiniYamlNode node;
-			if ((node = yaml.Nodes.FirstOrDefault(n => n.Key == section)) != null)
-				files = FieldLoader.GetValue<string[]>(section, node.Value.Value);
-		}
-
 		/// <summary>
 		/// Initializes a new map created by the editor or importer.
 		/// The map will not receive a valid UID until after it has been saved and reloaded.
@@ -208,6 +201,10 @@ namespace OpenRA
 			MapSize = new int2(size);
 			Tileset = tileset.Id;
 
+			// Empty rules that can be added to by the importers.
+			// Will be dropped on save if nothing is added to it
+			RuleDefinitions = new MiniYaml("");
+
 			MapResources = Exts.Lazy(() => new CellLayer<ResourceTile>(Grid.Type, size));
 
 			MapTiles = Exts.Lazy(() =>
@@ -260,14 +257,14 @@ namespace OpenRA
 				return spawns.ToArray();
 			});
 
-			LoadFileList(yaml, "Rules", ref RuleDefinitions);
-			LoadFileList(yaml, "Sequences", ref SequenceDefinitions);
-			LoadFileList(yaml, "VoxelSequences", ref VoxelSequenceDefinitions);
-			LoadFileList(yaml, "Weapons", ref WeaponDefinitions);
-			LoadFileList(yaml, "Voices", ref VoiceDefinitions);
-			LoadFileList(yaml, "Music", ref MusicDefinitions);
-			LoadFileList(yaml, "Notifications", ref NotificationDefinitions);
-			LoadFileList(yaml, "Translations", ref TranslationDefinitions);
+			RuleDefinitions = LoadRuleSection(yaml, "Rules");
+			SequenceDefinitions = LoadRuleSection(yaml, "Sequences");
+			VoxelSequenceDefinitions = LoadRuleSection(yaml, "VoxelSequences");
+			WeaponDefinitions = LoadRuleSection(yaml, "Weapons");
+			VoiceDefinitions = LoadRuleSection(yaml, "Voices");
+			MusicDefinitions = LoadRuleSection(yaml, "Music");
+			NotificationDefinitions = LoadRuleSection(yaml, "Notifications");
+			TranslationDefinitions = LoadRuleSection(yaml, "Translations");
 
 			PlayerDefinitions = MiniYaml.NodesOrEmpty(yaml, "Players");
 			ActorDefinitions = MiniYaml.NodesOrEmpty(yaml, "Actors");
@@ -287,6 +284,12 @@ namespace OpenRA
 			Uid = ComputeUID(Package);
 		}
 
+		MiniYaml LoadRuleSection(MiniYaml yaml, string section)
+		{
+			var node = yaml.Nodes.FirstOrDefault(n => n.Key == section);
+			return node != null ? node.Value : null;
+		}
+
 		void PostInit()
 		{
 			rules = Exts.Lazy(() =>
@@ -448,21 +451,21 @@ namespace OpenRA
 			root.Add(new MiniYamlNode("Players", null, PlayerDefinitions));
 			root.Add(new MiniYamlNode("Actors", null, ActorDefinitions));
 
-			var fileFields = new[]
+			var ruleSections = new[]
 			{
-				Pair.New("Rules", RuleDefinitions),
-				Pair.New("Sequences", SequenceDefinitions),
-				Pair.New("VoxelSequences", VoxelSequenceDefinitions),
-				Pair.New("Weapons", WeaponDefinitions),
-				Pair.New("Voices", VoiceDefinitions),
-				Pair.New("Music", MusicDefinitions),
-				Pair.New("Notifications", NotificationDefinitions),
-				Pair.New("Translations", TranslationDefinitions)
+				new MiniYamlNode("Rules", RuleDefinitions),
+				new MiniYamlNode("Sequences", SequenceDefinitions),
+				new MiniYamlNode("VoxelSequences", VoxelSequenceDefinitions),
+				new MiniYamlNode("Weapons", WeaponDefinitions),
+				new MiniYamlNode("Voices", VoiceDefinitions),
+				new MiniYamlNode("Music", MusicDefinitions),
+				new MiniYamlNode("Notifications", NotificationDefinitions),
+				new MiniYamlNode("Translations", TranslationDefinitions)
 			};
 
-			foreach (var kv in fileFields)
-				if (kv.Second.Any())
-					root.Add(new MiniYamlNode(kv.First, FieldSaver.FormatValue(kv.Second)));
+			foreach (var section in ruleSections)
+				if (section.Value != null && (section.Value.Value != null || section.Value.Nodes.Any()))
+					root.Add(section);
 
 			// Saving to a new package: copy over all the content from the map
 			if (Package != null && toPackage != Package)
diff --git a/OpenRA.Game/MiniYaml.cs b/OpenRA.Game/MiniYaml.cs
index 17d205ae6f..bcc4fe5e60 100644
--- a/OpenRA.Game/MiniYaml.cs
+++ b/OpenRA.Game/MiniYaml.cs
@@ -13,6 +13,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using OpenRA.FileSystem;
 
 namespace OpenRA
 {
@@ -375,6 +376,21 @@ namespace OpenRA
 				foreach (var line in Nodes.ToLines(false))
 					yield return "\t" + line;
 		}
+
+		public static List<MiniYamlNode> Load(IReadOnlyFileSystem fileSystem, IEnumerable<string> files, MiniYaml mapRules)
+		{
+			if (mapRules != null && mapRules.Value != null)
+			{
+				var mapFiles = FieldLoader.GetValue<string[]>("value", mapRules.Value);
+				files = files.Append(mapFiles);
+			}
+
+			var yaml = files.Select(s => MiniYaml.FromStream(fileSystem.Open(s)));
+			if (mapRules != null && mapRules.Nodes.Any())
+				yaml = yaml.Append(mapRules.Nodes);
+
+			return MiniYaml.Merge(yaml);
+		}
 	}
 
 	[Serializable]
diff --git a/OpenRA.Game/ModData.cs b/OpenRA.Game/ModData.cs
index 605a823847..b20b31e25c 100644
--- a/OpenRA.Game/ModData.cs
+++ b/OpenRA.Game/ModData.cs
@@ -130,8 +130,7 @@ namespace OpenRA
 				return;
 			}
 
-			var yaml = MiniYaml.Merge(Manifest.Translations.Append(map.TranslationDefinitions)
-				.Select(t => MiniYaml.FromStream(map.Open(t))));
+			var yaml = MiniYaml.Load(map, Manifest.Translations, map.TranslationDefinitions);
 			Languages = yaml.Select(t => t.Key).ToArray();
 
 			foreach (var y in yaml)
@@ -182,7 +181,7 @@ namespace OpenRA
 				foreach (var entry in map.Rules.Music)
 					entry.Value.Load(map);
 
-			VoxelProvider.Initialize(VoxelLoader, map, Manifest.VoxelSequences.Append(map.VoxelSequenceDefinitions));
+			VoxelProvider.Initialize(VoxelLoader, map, MiniYaml.Load(map, Manifest.VoxelSequences, map.VoxelSequenceDefinitions));
 			VoxelLoader.Finish();
 
 			return map;
diff --git a/OpenRA.Game/Server/Server.cs b/OpenRA.Game/Server/Server.cs
index 0d14b76022..d46e7b2522 100644
--- a/OpenRA.Game/Server/Server.cs
+++ b/OpenRA.Game/Server/Server.cs
@@ -392,7 +392,7 @@ namespace OpenRA.Server
 						SendOrderTo(newConn, "Message", motd);
 				}
 
-				if (Map.RuleDefinitions.Any() && !LobbyInfo.IsSinglePlayer)
+				if (Map.RuleDefinitions != null && !LobbyInfo.IsSinglePlayer)
 					SendOrderTo(newConn, "Message", "This map contains custom rules. Game experience may change.");
 
 				if (Settings.DisableSinglePlayer)
diff --git a/OpenRA.Mods.Common/Lint/CheckSequences.cs b/OpenRA.Mods.Common/Lint/CheckSequences.cs
index 55d3b1dabc..d1ed7d0e72 100644
--- a/OpenRA.Mods.Common/Lint/CheckSequences.cs
+++ b/OpenRA.Mods.Common/Lint/CheckSequences.cs
@@ -26,18 +26,17 @@ namespace OpenRA.Mods.Common.Lint
 
 		public void Run(Action<string> emitError, Action<string> emitWarning, Map map)
 		{
-			if (map != null && !map.SequenceDefinitions.Any())
+			if (map.SequenceDefinitions == null)
 				return;
 
 			var modData = Game.ModData;
 			this.emitError = emitError;
 
-			var mapSequences = map != null ? map.SequenceDefinitions : new string[0];
-			sequenceDefinitions = MiniYaml.Merge(modData.Manifest.Sequences.Append(mapSequences).Select(s => MiniYaml.FromStream(map.Open(s))));
+			sequenceDefinitions = MiniYaml.Load(map, modData.Manifest.Sequences, map.SequenceDefinitions);
 
-			var rules = map == null ? modData.DefaultRules : map.Rules;
+			var rules = map.Rules;
 			var factions = rules.Actors["world"].TraitInfos<FactionInfo>().Select(f => f.InternalName).ToArray();
-			var sequenceProviders = map == null ? rules.Sequences.Values : new[] { rules.Sequences[map.Tileset] };
+			var sequenceProviders = new[] { rules.Sequences[map.Tileset] };
 
 			foreach (var actorInfo in rules.Actors)
 			{
diff --git a/OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs b/OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs
index 5089f8b7ca..0285393c24 100644
--- a/OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs
+++ b/OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs
@@ -387,7 +387,7 @@ namespace OpenRA.Mods.Common.Server
 
 						server.SendMessage("{0} changed the map to {1}.".F(client.Name, server.Map.Title));
 
-						if (server.Map.RuleDefinitions.Any())
+						if (server.Map.RuleDefinitions != null)
 							server.SendMessage("This map contains custom rules. Game experience may change.");
 
 						if (server.Settings.DisableSinglePlayer)
diff --git a/OpenRA.Mods.Common/UtilityCommands/CheckYaml.cs b/OpenRA.Mods.Common/UtilityCommands/CheckYaml.cs
index 2a96940697..943fb2edb2 100644
--- a/OpenRA.Mods.Common/UtilityCommands/CheckYaml.cs
+++ b/OpenRA.Mods.Common/UtilityCommands/CheckYaml.cs
@@ -90,7 +90,7 @@ namespace OpenRA.Mods.Common.UtilityCommands
 					testMap.PreloadRules();
 
 					// Run all rule checks on the map if it defines custom rules.
-					if (testMap.RuleDefinitions.Any() || testMap.VoiceDefinitions.Any() || testMap.WeaponDefinitions.Any())
+					if (testMap.RuleDefinitions != null || testMap.VoiceDefinitions != null || testMap.WeaponDefinitions != null)
 						CheckRules(modData, testMap.Rules, testMap);
 
 					// Run all map-level checks here.
diff --git a/OpenRA.Mods.Common/UtilityCommands/ImportLegacyMapCommand.cs b/OpenRA.Mods.Common/UtilityCommands/ImportLegacyMapCommand.cs
index 9d469750b3..28ee6125a2 100644
--- a/OpenRA.Mods.Common/UtilityCommands/ImportLegacyMapCommand.cs
+++ b/OpenRA.Mods.Common/UtilityCommands/ImportLegacyMapCommand.cs
@@ -33,10 +33,8 @@ namespace OpenRA.Mods.Common.UtilityCommands
 
 		public ModData ModData;
 		public Map Map;
-		public IReadWritePackage Package;
 		public List<string> Players = new List<string>();
 		public MapPlayers MapPlayers;
-		public MiniYaml Rules = new MiniYaml("");
 
 		public bool ValidateArguments(string[] args)
 		{
@@ -52,8 +50,6 @@ namespace OpenRA.Mods.Common.UtilityCommands
 			Game.ModData = modData;
 
 			var filename = args[1];
-			var dest = Path.GetFileNameWithoutExtension(args[1]) + ".oramap";
-			Package = new ZipFile(modData.ModFiles, dest, true);
 			using (var stream = modData.DefaultFileSystem.Open(filename))
 			{
 				var file = new IniFile(stream);
@@ -67,7 +63,7 @@ namespace OpenRA.Mods.Common.UtilityCommands
 				Map = new Map(modData, modData.DefaultRules.TileSets[tileset], MapSize, MapSize)
 				{
 					Title = basic.GetValue("Name", Path.GetFileNameWithoutExtension(filename)),
-					Author = "Westwood Studios"
+					Author = "Westwood Studios",
 				};
 
 				Map.RequiresMod = modData.Manifest.Mod.Id;
@@ -96,16 +92,10 @@ namespace OpenRA.Mods.Common.UtilityCommands
 
 			Map.FixOpenAreas();
 
-			if (Rules.Nodes.Any())
-			{
-				// HACK: bypassing the readonly modifier here is still better than leaving this mutable by everyone
-				typeof(Map).GetField("RuleDefinitions").SetValue(Map, new[] { "rules.yaml" });
+			var dest = Path.GetFileNameWithoutExtension(args[1]) + ".oramap";
+			var package = new ZipFile(modData.ModFiles, dest, true);
 
-				var rulesText = Rules.Nodes.ToLines(false).JoinWith("\n");
-				Package.Update("rules.yaml", System.Text.Encoding.ASCII.GetBytes(rulesText));
-			}
-
-			Map.Save(Package);
+			Map.Save(package);
 			Console.WriteLine(dest + " saved.");
 		}
 
@@ -140,11 +130,11 @@ namespace OpenRA.Mods.Common.UtilityCommands
 			if (briefing.Length == 0)
 				return;
 
-			var worldNode = Rules.Nodes.FirstOrDefault(n => n.Key == "World");
+			var worldNode = Map.RuleDefinitions.Nodes.FirstOrDefault(n => n.Key == "World");
 			if (worldNode == null)
 			{
 				worldNode = new MiniYamlNode("World", new MiniYaml("", new List<MiniYamlNode>()));
-				Rules.Nodes.Add(worldNode);
+				Map.RuleDefinitions.Nodes.Add(worldNode);
 			}
 
 			var missionData = worldNode.Value.Nodes.FirstOrDefault(n => n.Key == "MissionData");
@@ -201,11 +191,11 @@ namespace OpenRA.Mods.Common.UtilityCommands
 
 			if (videos.Any())
 			{
-				var worldNode = Rules.Nodes.FirstOrDefault(n => n.Key == "World");
+				var worldNode = Map.RuleDefinitions.Nodes.FirstOrDefault(n => n.Key == "World");
 				if (worldNode == null)
 				{
 					worldNode = new MiniYamlNode("World", new MiniYaml("", new List<MiniYamlNode>()));
-					Rules.Nodes.Add(worldNode);
+					Map.RuleDefinitions.Nodes.Add(worldNode);
 				}
 
 				var missionData = worldNode.Value.Nodes.FirstOrDefault(n => n.Key == "MissionData");
@@ -298,7 +288,7 @@ namespace OpenRA.Mods.Common.UtilityCommands
 					craters.Add(node);
 			}
 
-			var worldNode = Rules.Nodes.FirstOrDefault(n => n.Key == "World");
+			var worldNode = Map.RuleDefinitions.Nodes.FirstOrDefault(n => n.Key == "World");
 			if (worldNode == null)
 				worldNode = new MiniYamlNode("World", new MiniYaml("", new List<MiniYamlNode>()));
 
@@ -316,8 +306,8 @@ namespace OpenRA.Mods.Common.UtilityCommands
 				worldNode.Value.Nodes.Add(smudgeLayer);
 			}
 
-			if (worldNode.Value.Nodes.Any() && !Rules.Nodes.Contains(worldNode))
-				Rules.Nodes.Add(worldNode);
+			if (worldNode.Value.Nodes.Any() && !Map.RuleDefinitions.Nodes.Contains(worldNode))
+				Map.RuleDefinitions.Nodes.Add(worldNode);
 		}
 
 		// TODO: fix this -- will have bitrotted pretty badly.
diff --git a/OpenRA.Mods.Common/UtilityCommands/UpgradeMapCommand.cs b/OpenRA.Mods.Common/UtilityCommands/UpgradeMapCommand.cs
index cc9da3aac3..6e608c58fc 100644
--- a/OpenRA.Mods.Common/UtilityCommands/UpgradeMapCommand.cs
+++ b/OpenRA.Mods.Common/UtilityCommands/UpgradeMapCommand.cs
@@ -27,17 +27,23 @@ namespace OpenRA.Mods.Common.UtilityCommands
 
 		delegate void UpgradeAction(int engineVersion, ref List<MiniYamlNode> nodes, MiniYamlNode parent, int depth);
 
-		static void ProcessYaml(Map map, IEnumerable<string> files, int engineDate, UpgradeAction processFile)
+		static void ProcessYaml(Map map, MiniYaml yaml, int engineDate, UpgradeAction processYaml)
 		{
-		    foreach (var filename in files)
-		    {
-		        if (!map.Package.Contains(filename))
-		            continue;
+			if (yaml == null)
+				return;
 
-		        var yaml = MiniYaml.FromStream(map.Package.GetStream(filename));
-		        processFile(engineDate, ref yaml, null, 0);
-		        ((IReadWritePackage)map.Package).Update(filename, Encoding.ASCII.GetBytes(yaml.WriteToString()));
-		    }
+			if (yaml.Value != null)
+			{
+				var files = FieldLoader.GetValue<string[]>("value", yaml.Value);
+			    foreach (var filename in files)
+			    {
+			        var fileNodes = MiniYaml.FromStream(map.Package.GetStream(filename));
+					processYaml(engineDate, ref fileNodes, null, 0);
+			        ((IReadWritePackage)map.Package).Update(filename, Encoding.ASCII.GetBytes(fileNodes.WriteToString()));
+			    }
+			}
+
+			processYaml(engineDate, ref yaml.Nodes, null, 1);
 		}
 
 		public static void UpgradeMap(ModData modData, IReadWritePackage package, int engineDate)
diff --git a/OpenRA.Mods.Common/UtilityCommands/UpgradeRules.cs b/OpenRA.Mods.Common/UtilityCommands/UpgradeRules.cs
index 153bbdf4e9..bbe3067d1d 100644
--- a/OpenRA.Mods.Common/UtilityCommands/UpgradeRules.cs
+++ b/OpenRA.Mods.Common/UtilityCommands/UpgradeRules.cs
@@ -948,20 +948,10 @@ namespace OpenRA.Mods.Common.UtilityCommands
 					rules.Value.Nodes.Add(playerNode);
 			}
 
-			// Format 9 -> 10 extracted map rules, sequences, voxelsequences, weapons, voices, music, notifications,
-			// and translations to external files, moved smudges to SmudgeLayer, and uses map.png for all maps
+			// Format 9 -> 10 moved smudges to SmudgeLayer, and uses map.png for all maps
 			if (mapFormat < 10)
 			{
 				ExtractSmudges(yaml);
-				ExtractOrRemoveRules(package, yaml, "Rules", "rules.yaml");
-				ExtractOrRemoveRules(package, yaml, "Sequences", "sequences.yaml");
-				ExtractOrRemoveRules(package, yaml, "VoxelSequences", "voxels.yaml");
-				ExtractOrRemoveRules(package, yaml, "Weapons", "weapons.yaml");
-				ExtractOrRemoveRules(package, yaml, "Voices", "voices.yaml");
-				ExtractOrRemoveRules(package, yaml, "Music", "music.yaml");
-				ExtractOrRemoveRules(package, yaml, "Notifications", "notifications.yaml");
-				ExtractOrRemoveRules(package, yaml, "Translations", "translations.yaml");
-
 				if (package.Contains("map.png"))
 					yaml.Nodes.Add(new MiniYamlNode("LockPreview", new MiniYaml("True")));
 			}
@@ -1023,22 +1013,5 @@ namespace OpenRA.Mods.Common.UtilityCommands
 				worldNode.Value.Nodes.Add(smudgeLayer);
 			}
 		}
-
-		static void ExtractOrRemoveRules(IReadWritePackage package, MiniYaml yaml, string key, string filename)
-		{
-			var node = yaml.Nodes.FirstOrDefault(n => n.Key == key);
-			if (node == null)
-				return;
-
-			if (node.Value.Nodes.Any())
-			{
-				var rulesText = node.Value.Nodes.ToLines(false).JoinWith("\n");
-				package.Update(filename, System.Text.Encoding.ASCII.GetBytes(rulesText));
-				node.Value.Value = filename;
-				node.Value.Nodes.Clear();
-			}
-			else
-				yaml.Nodes.Remove(node);
-		}
 	}
 }
diff --git a/OpenRA.Mods.TS/UtilityCommands/ImportTSMapCommand.cs b/OpenRA.Mods.TS/UtilityCommands/ImportTSMapCommand.cs
index 48eda4f34c..16d4477e55 100644
--- a/OpenRA.Mods.TS/UtilityCommands/ImportTSMapCommand.cs
+++ b/OpenRA.Mods.TS/UtilityCommands/ImportTSMapCommand.cs
@@ -165,8 +165,6 @@ namespace OpenRA.Mods.TS.UtilityCommands
 			var filename = args[1];
 			var file = new IniFile(File.Open(args[1], FileMode.Open));
 			var map = GenerateMapHeader(filename, file, modData);
-			var dest = Path.GetFileNameWithoutExtension(args[1]) + ".oramap";
-			var package = new ZipFile(modData.DefaultFileSystem, dest, true);
 
 			ReadTiles(map, file);
 			ReadActors(map, file, "Structures");
@@ -175,11 +173,13 @@ namespace OpenRA.Mods.TS.UtilityCommands
 			ReadTerrainActors(map, file);
 			ReadWaypoints(map, file);
 			ReadOverlay(map, file);
-			ReadLighting(map, package, file);
+			ReadLighting(map, file);
 
 			var mapPlayers = new MapPlayers(map.Rules, spawnCount);
 			map.PlayerDefinitions = mapPlayers.ToMiniYaml();
 
+			var dest = Path.GetFileNameWithoutExtension(args[1]) + ".oramap";
+			var package = new ZipFile(modData.DefaultFileSystem, dest, true);
 			map.Save(package);
 			Console.WriteLine(dest + " saved.");
 		}
@@ -431,12 +431,11 @@ namespace OpenRA.Mods.TS.UtilityCommands
 			}
 		}
 
-		void ReadLighting(Map map, IReadWritePackage package, IniFile file)
+		void ReadLighting(Map map, IniFile file)
 		{
 			var lightingTypes = new[] { "Red", "Green", "Blue", "Ambient" };
 			var lightingSection = file.GetSection("Lighting");
-			var lightingNode = new MiniYamlNode("GlobalLightingPaletteEffect", new MiniYaml("", new List<MiniYamlNode>()));
-			var worldNode = new MiniYamlNode("World", new MiniYaml("", new List<MiniYamlNode>() { lightingNode }));
+			var lightingNodes = new List<MiniYamlNode>();
 
 			foreach (var kv in lightingSection)
 			{
@@ -444,19 +443,18 @@ namespace OpenRA.Mods.TS.UtilityCommands
 				{
 					var val = FieldLoader.GetValue<float>(kv.Key, kv.Value);
 					if (val != 1.0f)
-						lightingNode.Value.Nodes.Add(new MiniYamlNode(kv.Key, FieldSaver.FormatValue(val)));
+						lightingNodes.Add(new MiniYamlNode(kv.Key, FieldSaver.FormatValue(val)));
 				}
 				else
 					Console.WriteLine("Ignoring unknown lighting type: `{0}`".F(kv.Key));
 			}
 
-			if (lightingNode.Value.Nodes.Any())
+			if (lightingNodes.Any())
 			{
-				// HACK: bypassing the readonly modifier here is still better than leaving this mutable by everyone
-				typeof(Map).GetField("RuleDefinitions").SetValue(map, new[] { "rules.yaml" });
-
-				var rulesText = new List<MiniYamlNode>() { worldNode }.ToLines(false).JoinWith("\n");
-				package.Update("rules.yaml", System.Text.Encoding.ASCII.GetBytes(rulesText));
+				map.RuleDefinitions.Nodes.Add(new MiniYamlNode("World", new MiniYaml("", new List<MiniYamlNode>()
+				{
+					new MiniYamlNode("GlobalLightingPaletteEffect", new MiniYaml("", lightingNodes))
+				})));
 			}
 		}
 	}
diff --git a/mods/ts/maps/arivruns/map.yaml b/mods/ts/maps/arivruns/map.yaml
index 6aac0348d3..e20d40fac8 100644
--- a/mods/ts/maps/arivruns/map.yaml
+++ b/mods/ts/maps/arivruns/map.yaml
@@ -1293,4 +1293,7 @@ Actors:
 		Owner: Neutral
 		Location: 115,-15
 
-Rules: rules.yaml
+Rules:
+	World:
+		GlobalLightingPaletteEffect:
+			Ambient: 0.72
diff --git a/mods/ts/maps/arivruns/rules.yaml b/mods/ts/maps/arivruns/rules.yaml
deleted file mode 100644
index f8fa63e382..0000000000
--- a/mods/ts/maps/arivruns/rules.yaml
+++ /dev/null
@@ -1,3 +0,0 @@
-World:
-	GlobalLightingPaletteEffect:
-		Ambient: 0.72
diff --git a/mods/ts/maps/cliffsin/map.yaml b/mods/ts/maps/cliffsin/map.yaml
index 49aa13d7bd..c76b6cb8dc 100644
--- a/mods/ts/maps/cliffsin/map.yaml
+++ b/mods/ts/maps/cliffsin/map.yaml
@@ -1499,4 +1499,7 @@ Actors:
 		Location: 123,87
 		Owner: Neutral
 
-Rules: rules.yaml
+Rules:
+	World:
+		GlobalLightingPaletteEffect:
+			Ambient: 0.68
diff --git a/mods/ts/maps/cliffsin/rules.yaml b/mods/ts/maps/cliffsin/rules.yaml
deleted file mode 100644
index 60f2701725..0000000000
--- a/mods/ts/maps/cliffsin/rules.yaml
+++ /dev/null
@@ -1,3 +0,0 @@
-World:
-	GlobalLightingPaletteEffect:
-		Ambient: 0.68
diff --git a/mods/ts/maps/gdi4a/map.yaml b/mods/ts/maps/gdi4a/map.yaml
index 6a02f07652..cf07cbe862 100644
--- a/mods/ts/maps/gdi4a/map.yaml
+++ b/mods/ts/maps/gdi4a/map.yaml
@@ -1737,3 +1737,9 @@ Actors:
 		Location: 111,13
 
 Rules: rules.yaml
+	World:
+		GlobalLightingPaletteEffect:
+			Red: 1.1
+			Green: 1.1
+			Blue: 1
+			Ambient: 0.55
\ No newline at end of file
diff --git a/mods/ts/maps/gdi4a/rules.yaml b/mods/ts/maps/gdi4a/rules.yaml
index adfe77c8ab..eba63b3e66 100644
--- a/mods/ts/maps/gdi4a/rules.yaml
+++ b/mods/ts/maps/gdi4a/rules.yaml
@@ -4,10 +4,5 @@ World:
 	-MPStartLocations:
 	MusicPlaylist:
 		BackgroundMusic: intro
-	GlobalLightingPaletteEffect:
-		Red: 1.1
-		Green: 1.1
-		Blue: 1
-		Ambient: 0.55
 	LuaScript:
 		Scripts: map.lua
diff --git a/mods/ts/maps/karasjok/map.yaml b/mods/ts/maps/karasjok/map.yaml
index 4969205cef..9cf66da2b9 100644
--- a/mods/ts/maps/karasjok/map.yaml
+++ b/mods/ts/maps/karasjok/map.yaml
@@ -1554,4 +1554,10 @@ Actors:
 		Location: 134,73
 		Owner: Neutral
 
-Rules: rules.yaml
+Rules:
+	World:
+		GlobalLightingPaletteEffect:
+			Red: 0.5
+			Green: 0.7
+			Blue: 0.7
+			Ambient: 0.78
\ No newline at end of file
diff --git a/mods/ts/maps/karasjok/rules.yaml b/mods/ts/maps/karasjok/rules.yaml
deleted file mode 100644
index de64efd8cd..0000000000
--- a/mods/ts/maps/karasjok/rules.yaml
+++ /dev/null
@@ -1,6 +0,0 @@
-World:
-	GlobalLightingPaletteEffect:
-		Red: 0.5
-		Blue: 0.7
-		Green: 0.7
-		Ambient: 0.78
diff --git a/mods/ts/maps/rivrrad4/map.yaml b/mods/ts/maps/rivrrad4/map.yaml
index 129d01f1f1..218b7acb15 100644
--- a/mods/ts/maps/rivrrad4/map.yaml
+++ b/mods/ts/maps/rivrrad4/map.yaml
@@ -868,4 +868,7 @@ Actors:
 		Location: 254,39
 		Owner: Neutral
 
-Rules: rules.yaml
+Rules:
+	World:
+		GlobalLightingPaletteEffect:
+			Ambient: 0.85
diff --git a/mods/ts/maps/rivrrad4/rules.yaml b/mods/ts/maps/rivrrad4/rules.yaml
deleted file mode 100644
index 7493f42ace..0000000000
--- a/mods/ts/maps/rivrrad4/rules.yaml
+++ /dev/null
@@ -1,3 +0,0 @@
-World:
-	GlobalLightingPaletteEffect:
-		Ambient: 0.85
diff --git a/mods/ts/maps/springs/map.yaml b/mods/ts/maps/springs/map.yaml
index 13f41bb60e..6241f0ff5a 100644
--- a/mods/ts/maps/springs/map.yaml
+++ b/mods/ts/maps/springs/map.yaml
@@ -853,4 +853,7 @@ Actors:
 		Owner: Neutral
 		Location: 95,3
 
-Rules: rules.yaml
+Rules:
+	World:
+		GlobalLightingPaletteEffect:
+			Ambient: 0.62
diff --git a/mods/ts/maps/springs/rules.yaml b/mods/ts/maps/springs/rules.yaml
deleted file mode 100644
index 4ff8dd87ae..0000000000
--- a/mods/ts/maps/springs/rules.yaml
+++ /dev/null
@@ -1,3 +0,0 @@
-World:
-	GlobalLightingPaletteEffect:
-		Ambient: 0.62
diff --git a/mods/ts/maps/t_garden/map.yaml b/mods/ts/maps/t_garden/map.yaml
index d632589d50..7b36079229 100644
--- a/mods/ts/maps/t_garden/map.yaml
+++ b/mods/ts/maps/t_garden/map.yaml
@@ -830,4 +830,7 @@ Actors:
 		Location: 99,74
 		Owner: Neutral
 
-Rules: rules.yaml
+Rules:
+	World:
+		GlobalLightingPaletteEffect:
+			Ambient: 0.79
diff --git a/mods/ts/maps/t_garden/rules.yaml b/mods/ts/maps/t_garden/rules.yaml
deleted file mode 100644
index 005365fd83..0000000000
--- a/mods/ts/maps/t_garden/rules.yaml
+++ /dev/null
@@ -1,6 +0,0 @@
-World:
-	GlobalLightingPaletteEffect:
-		Red: 1
-		Blue: 1
-		Green: 1
-		Ambient: 0.79
diff --git a/mods/ts/maps/tactical/map.yaml b/mods/ts/maps/tactical/map.yaml
index 96783707ed..65cf128c8c 100644
--- a/mods/ts/maps/tactical/map.yaml
+++ b/mods/ts/maps/tactical/map.yaml
@@ -800,4 +800,7 @@ Actors:
 		Location: 167,83
 		Owner: Neutral
 
-Rules: rules.yaml
+Rules:
+	World:
+		GlobalLightingPaletteEffect:
+			Ambient: 0.85
diff --git a/mods/ts/maps/tactical/rules.yaml b/mods/ts/maps/tactical/rules.yaml
deleted file mode 100644
index 7493f42ace..0000000000
--- a/mods/ts/maps/tactical/rules.yaml
+++ /dev/null
@@ -1,3 +0,0 @@
-World:
-	GlobalLightingPaletteEffect:
-		Ambient: 0.85
diff --git a/mods/ts/maps/terrace/map.yaml b/mods/ts/maps/terrace/map.yaml
index 3263c9db70..ae12bad0a1 100644
--- a/mods/ts/maps/terrace/map.yaml
+++ b/mods/ts/maps/terrace/map.yaml
@@ -509,4 +509,7 @@ Actors:
 		Location: 84,60
 		Owner: Neutral
 
-Rules: rules.yaml
+Rules:
+	World:
+		GlobalLightingPaletteEffect:
+			Ambient: 0.63
diff --git a/mods/ts/maps/terrace/rules.yaml b/mods/ts/maps/terrace/rules.yaml
deleted file mode 100644
index 7bd64ec853..0000000000
--- a/mods/ts/maps/terrace/rules.yaml
+++ /dev/null
@@ -1,3 +0,0 @@
-World:
-	GlobalLightingPaletteEffect:
-		Ambient: 0.63
diff --git a/mods/ts/maps/tread_l/map.yaml b/mods/ts/maps/tread_l/map.yaml
index a27cd3c2fc..095f365317 100644
--- a/mods/ts/maps/tread_l/map.yaml
+++ b/mods/ts/maps/tread_l/map.yaml
@@ -1213,4 +1213,7 @@ Actors:
 		Location: 123,20
 		Owner: Neutral
 
-Rules: rules.yaml
+Rules:
+	World:
+		GlobalLightingPaletteEffect:
+			Ambient: 0.75
diff --git a/mods/ts/maps/tread_l/rules.yaml b/mods/ts/maps/tread_l/rules.yaml
deleted file mode 100644
index 9fad12c1dc..0000000000
--- a/mods/ts/maps/tread_l/rules.yaml
+++ /dev/null
@@ -1,3 +0,0 @@
-World:
-	GlobalLightingPaletteEffect:
-		Ambient: 0.75