diff --git a/PckStudio.Core/DLC/DLCMashUpPackage.cs b/PckStudio.Core/DLC/DLCMashUpPackage.cs
index e2008d49..fadd82cc 100644
--- a/PckStudio.Core/DLC/DLCMashUpPackage.cs
+++ b/PckStudio.Core/DLC/DLCMashUpPackage.cs
@@ -18,16 +18,14 @@ namespace PckStudio.Core.DLC
 
         private IDLCPackage _skinPackage;
         private IDLCPackage _texturePackage;
-        private AbstractGameRule _gameRule;
+        private MapData _mapData;
         private IDictionary<string, byte[]> _audioData;
         private PckAudioFile _pckAudio;
-        private NamedData<byte[]> _savegameData;
 
         internal DLCMashUpPackage(string name, string description, int identifier, IDLCPackageSerialization packageInfo, AbstractGameRule gameRule, IDLCPackage parentPackage, IDLCPackage skinPackage = null, IDLCPackage texturePackage = null)
             : base(name, identifier, packageInfo, parentPackage)
         {
             Description = description;
-            _gameRule = gameRule;
             _skinPackage = skinPackage;
             _texturePackage = texturePackage;
         }
@@ -37,18 +35,8 @@ namespace PckStudio.Core.DLC
         {
             _skinPackage = DLCSkinPackage.CreateEmpty(this);
             _texturePackage = DLCTexturePackage.CreateDefaultPackage(this);
-            _savegameData = new NamedData<byte[]>("world.mcs", Array.Empty<byte>());
             _audioData = new Dictionary<string, byte[]>();
             _pckAudio = new PckAudioFile();
-
-            //! TODO(null): only create grf when adding savefile ?...
-            _gameRule.AddRule(new NamedRule("MapOptions",
-                new GameRuleFile.IntParameter("seed", 0),
-                new GameRuleFile.GameRuleParameter("baseSaveName", _savegameData.Name),
-                new GameRuleFile.BoolParameter("flatworld", false),
-                new GameRuleFile.IntParameter("texturePackId", Identifier))
-                );
-            _gameRule.AddRule(LevelRules.GetDefault(pos: Vector3.Zero, rot: Vector2.Zero));
         }
 
         public IDLCPackage GetSkinPackage() => _skinPackage;
diff --git a/PckStudio.Core/DLC/DLCMiniGamePackage.cs b/PckStudio.Core/DLC/DLCMiniGamePackage.cs
index a3c416dc..16e432cf 100644
--- a/PckStudio.Core/DLC/DLCMiniGamePackage.cs
+++ b/PckStudio.Core/DLC/DLCMiniGamePackage.cs
@@ -23,7 +23,7 @@ namespace PckStudio.Core.DLC
 
         public void AddMap(string name, Image thumbnail, MapSize mapSize, NamedData<byte[]> world)
         {
-            _maps.Add(new MapData(name, thumbnail, _miniGameId, mapSize, world));
+            _maps.Add(new MapData(name, thumbnail, world, _miniGameId, mapSize));
         }
 
         public override DLCPackageType GetDLCPackageType() => _packageType;
diff --git a/PckStudio.Core/GameRule/AbstractGameRule.cs b/PckStudio.Core/GameRule/AbstractGameRule.cs
index 8714465c..3a13e851 100644
--- a/PckStudio.Core/GameRule/AbstractGameRule.cs
+++ b/PckStudio.Core/GameRule/AbstractGameRule.cs
@@ -1,8 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+using System.Numerics;
 using OMI.Formats.GameRule;
 
 namespace PckStudio.Core.GameRule
@@ -10,14 +9,45 @@ namespace PckStudio.Core.GameRule
     public abstract class AbstractGameRule
     {
         private List<AbstractGameRule> _gameRules = new List<AbstractGameRule>();
+        private IDictionary<string, string> _parameters = new Dictionary<string, string>();
+
+        public abstract string Name { get; }
+
         public void AddRule(AbstractGameRule gameRule) => _gameRules.Add(gameRule);
         public void AddRules(IEnumerable<AbstractGameRule> gameRules) => _gameRules.AddRange(gameRules);
 
-        protected abstract GameRuleFile.GameRule GetGameRule();
+        public void AddParameter(string name, string value) => _parameters.Add(name, value);
+        public void AddParameter<T>(string name, T value) => AddParameter(name, value.ToString());
+        public void AddParameter(string name, bool value) => AddParameter(name, value.ToString().ToLower());
+        public void AddParameters(KeyValuePair<string, string>[] values)
+        {
+            foreach (KeyValuePair<string, string> value in values)
+            {
+                AddParameter(value.Key, value.Value);
+            }
+        }
+       
+        private string GetString(char c, string prefix, string suffix) => $"{prefix}{(string.IsNullOrWhiteSpace(prefix) ? char.ToLower(c) : char.ToUpper(c))}{suffix}";
+        
+        public void AddParameter(Vector2 vec2, string prefix = "", string suffix = "")
+        {
+            AddParameter(GetString('x', prefix, suffix), vec2.X);
+            AddParameter(GetString('y', prefix, suffix), vec2.Y);
+        }
+
+
+        public void AddParameter(Vector3 vec3, string prefix = "", string suffix = "")
+        {
+            AddParameter(new Vector2(vec3.X, vec3.Y), prefix, suffix);
+            AddParameter(GetString('z', prefix, suffix), vec3.Z);
+        }
+
         private GameRuleFile.GameRule InternalGetGameRule()
         {
+            _ = Name ?? throw new ArgumentNullException(nameof(Name));
             IEnumerable<GameRuleFile.GameRule> a = _gameRules.Select(agr => agr.InternalGetGameRule());
-            GameRuleFile.GameRule gameRule = GetGameRule();
+            GameRuleFile.GameRule gameRule = new GameRuleFile.GameRule(Name);
+            gameRule.AddParameters(_parameters.Select(kv => new GameRuleFile.GameRuleParameter(kv.Key, kv.Value)).ToArray());
             gameRule.AddRules(a);
             return gameRule;
         }
diff --git a/PckStudio.Core/GameRule/DistributeItems.cs b/PckStudio.Core/GameRule/DistributeItems.cs
index e86c70e2..c86b7f31 100644
--- a/PckStudio.Core/GameRule/DistributeItems.cs
+++ b/PckStudio.Core/GameRule/DistributeItems.cs
@@ -1,14 +1,13 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using OMI.Formats.GameRule;
 
 namespace PckStudio.Core.GameRule
 {
     public sealed class DistributeItems : AbstractGameRule
     {
+        public override string Name => "DistributeItems";
+
+        public void AddPosition(int x, int y, int z) => AddRule(new WorldPosition(x, y, z));
+
         private static string[] _idStrings =
         {
             "StartItems",
@@ -22,20 +21,10 @@ namespace PckStudio.Core.GameRule
             OuterItems,
             HighValueItems
         }
-        private DistributeItemsId _id;
-
-        public void AddPosition(int x, int y, int z) => AddRule(new WorldPosition(x, y, z));
-
+     
         internal DistributeItems(DistributeItemsId id)
         {
-            _id = id;
-        }
-
-        protected override GameRuleFile.GameRule GetGameRule()
-        {
-            var gameRule = new GameRuleFile.GameRule("DistributeItems");
-            gameRule.AddParameter(new GameRuleFile.GameRuleParameter("id", _idStrings[(int)_id]));
-            return gameRule;
+            AddParameter("id", _idStrings[(int)id]);
         }
     }
 }
diff --git a/PckStudio.Core/GameRule/LevelRules.cs b/PckStudio.Core/GameRule/LevelRules.cs
index 3ad79d8c..47caaa85 100644
--- a/PckStudio.Core/GameRule/LevelRules.cs
+++ b/PckStudio.Core/GameRule/LevelRules.cs
@@ -1,39 +1,30 @@
 using System;
-using System.Collections.Generic;
 using System.Linq;
 using System.Numerics;
-using System.Text;
-using System.Threading.Tasks;
-using OMI.Formats.GameRule;
+using System.Collections.Generic;
 
 namespace PckStudio.Core.GameRule
 {
     public sealed class LevelRules : AbstractGameRule
     {
-        private readonly GameRuleFile.GameRuleParameter[] _parameters;
-        private readonly MiniGameId _miniGameId;
+        public override string Name => "LevelRules";
+
+        public MiniGameId MiniGame { get; }
 
         public static LevelRules GetDefault(Vector3 pos, Vector2 rot) => new LevelRules([new UpdatePlayer(pos, rot)]);
         public static LevelRules GetMiniGameLevelRules(MiniGameId miniGame) => new LevelRules(miniGame);
 
-        public LevelRules(IEnumerable<AbstractGameRule> gameRules, MiniGameId miniGameId, params GameRuleFile.GameRuleParameter[] parameters)
+        public LevelRules(IEnumerable<AbstractGameRule> gameRules, MiniGameId miniGameId, params KeyValuePair<string, string>[] parameters)
         {
             AddRules(gameRules);
-            _parameters = parameters;
-            _miniGameId = miniGameId;
+            MiniGame = miniGameId;
+            if (miniGameId != MiniGameId.None)
+                AddParameter("ruleType", (int)miniGameId);
+            AddParameters(parameters);
         }
 
-        public LevelRules(IEnumerable<AbstractGameRule> gameRules, params GameRuleFile.GameRuleParameter[] parameters) : this(gameRules, MiniGameId.None, parameters) { }
+        public LevelRules(IEnumerable<AbstractGameRule> gameRules, params KeyValuePair<string, string>[] parameters) : this(gameRules, MiniGameId.None, parameters) { }
 
         public LevelRules(MiniGameId miniGameId) : this(Enumerable.Empty<AbstractGameRule>(), miniGameId) { }
-
-        protected override GameRuleFile.GameRule GetGameRule()
-        {
-            var gameRule = new GameRuleFile.GameRule("LevelRules");
-            if (_miniGameId != MiniGameId.None)
-                gameRule.AddParameter(new GameRuleFile.IntParameter("ruleType", (int)_miniGameId));
-            gameRule.AddParameters(_parameters);
-            return gameRule;
-        }
     }
 }
diff --git a/PckStudio.Core/GameRule/NamedArea.cs b/PckStudio.Core/GameRule/NamedArea.cs
index af115c0c..0f397a91 100644
--- a/PckStudio.Core/GameRule/NamedArea.cs
+++ b/PckStudio.Core/GameRule/NamedArea.cs
@@ -1,43 +1,25 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Numerics;
-using System.Text;
-using System.Threading.Tasks;
-using OMI.Formats.GameRule;
 using PckStudio.Core.Extensions;
 
 namespace PckStudio.Core.GameRule
 {
     internal sealed class NamedArea : AbstractGameRule
     {
-        public string Name { get; }
+        public override string Name => "NamedArea";
 
         public Vector3 Start { get; }
         public Vector3 End { get; }
 
         public NamedArea(string name, Vector3 start, Vector3 end)
         {
-            Name = name;
+            AddParameter("name", name);
+            AddParameter(start, suffix: "0");
+            AddParameter(end, suffix: "1");
             Start = start;
             End = end;
         }
 
         public NamedArea(string name, BoundingBox boundingBox) : this(name, boundingBox.Start.ToNumericsVector(), boundingBox.End.ToNumericsVector()) { }
-
-        protected override GameRuleFile.GameRule GetGameRule()
-        {
-            GameRuleFile.GameRule gameRule = new GameRuleFile.GameRule("NamedArea");
-            gameRule.AddParameters(
-                new GameRuleFile.GameRuleParameter("name", Name),
-                new GameRuleFile.FloatParameter("x0", Start.X),
-                new GameRuleFile.FloatParameter("y0", Start.Y),
-                new GameRuleFile.FloatParameter("z0", Start.Z),
-                new GameRuleFile.FloatParameter("x1", End.X),
-                new GameRuleFile.FloatParameter("y1", End.Y),
-                new GameRuleFile.FloatParameter("z1", End.Z)
-                );
-            return gameRule;
-        }
     }
 }
diff --git a/PckStudio.Core/GameRule/NamedRule.cs b/PckStudio.Core/GameRule/NamedRule.cs
index 0d80382f..19229652 100644
--- a/PckStudio.Core/GameRule/NamedRule.cs
+++ b/PckStudio.Core/GameRule/NamedRule.cs
@@ -1,28 +1,9 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using OMI.Formats.GameRule;
 
 namespace PckStudio.Core.GameRule
 {
-    internal sealed class NamedRule : AbstractGameRule
+    internal sealed class NamedRule(string name) : AbstractGameRule
     {
-        private readonly string _name;
-        private readonly GameRuleFile.GameRuleParameter[] _parameters;
-
-        public NamedRule(string name, params GameRuleFile.GameRuleParameter[] parameters)
-        {
-            _name = name;
-            _parameters = parameters;
-        }
-
-        protected override GameRuleFile.GameRule GetGameRule()
-        {
-            var rule = new GameRuleFile.GameRule(_name);
-            rule.AddParameters(_parameters);
-            return rule;
-        }
+        public override string Name => name;
     }
 }
diff --git a/PckStudio.Core/GameRule/OnGameStartSpawnPositions.cs b/PckStudio.Core/GameRule/OnGameStartSpawnPositions.cs
index d1eacbd1..ce1763de 100644
--- a/PckStudio.Core/GameRule/OnGameStartSpawnPositions.cs
+++ b/PckStudio.Core/GameRule/OnGameStartSpawnPositions.cs
@@ -1,23 +1,17 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Security.Cryptography;
-using System.Text;
-using System.Threading.Tasks;
-using OMI.Formats.GameRule;
 
 namespace PckStudio.Core.GameRule
 {
     public sealed class OnGameStartSpawnPositions : AbstractGameRule
     {
+        public override string Name => "OnGameStartSpawnPositions";
         public SpawnPositionSet OnStart { get; } = new SpawnPositionSet(SpawnPositionSet.SpanPositionMethod.OnStart);
         public SpawnPositionSet OnRespawn { get; } = new SpawnPositionSet(SpawnPositionSet.SpanPositionMethod.OnRespawn);
 
-        protected override GameRuleFile.GameRule GetGameRule()
+        public OnGameStartSpawnPositions()
         {
             AddRule(OnStart);
             AddRule(OnRespawn);
-            return new GameRuleFile.GameRule("OnGameStartSpawnPositions");
         }
     }
 }
diff --git a/PckStudio.Core/GameRule/OnInitialiseWorld.cs b/PckStudio.Core/GameRule/OnInitialiseWorld.cs
index 8bfaeb0a..0726657c 100644
--- a/PckStudio.Core/GameRule/OnInitialiseWorld.cs
+++ b/PckStudio.Core/GameRule/OnInitialiseWorld.cs
@@ -1,24 +1,20 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using OMI.Formats.GameRule;
 
 namespace PckStudio.Core.GameRule
 {
     public sealed class OnInitialiseWorld : AbstractGameRule
     {
+        public override string Name => "OnInitialiseWorld";
         public DistributeItems StartItems { get; } = new DistributeItems(DistributeItems.DistributeItemsId.StartItems);
         public DistributeItems OuterItems { get; } = new DistributeItems(DistributeItems.DistributeItemsId.OuterItems);
         public DistributeItems HighValueItems { get; } = new DistributeItems(DistributeItems.DistributeItemsId.HighValueItems);
 
-        protected override GameRuleFile.GameRule GetGameRule()
+
+        public OnInitialiseWorld()
         {
             AddRule(StartItems);
             AddRule(OuterItems);
             AddRule(HighValueItems);
-            return new GameRuleFile.GameRule("OnInitialiseWorld");
         }
     }
 }
diff --git a/PckStudio.Core/GameRule/RootGameRule.cs b/PckStudio.Core/GameRule/RootGameRule.cs
index 7447ef6a..08a7158d 100644
--- a/PckStudio.Core/GameRule/RootGameRule.cs
+++ b/PckStudio.Core/GameRule/RootGameRule.cs
@@ -1,14 +1,9 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using OMI.Formats.GameRule;
 
 namespace PckStudio.Core.GameRule
 {
     public sealed class RootGameRule : AbstractGameRule
     {
-        protected override GameRuleFile.GameRule GetGameRule() => new GameRuleFile.GameRule("__ROOT__"); //! name is irrelevant
+        public override string Name => "__ROOT__"; //! name is irrelevant
     }
 }
diff --git a/PckStudio.Core/GameRule/SpawnPositionSet.cs b/PckStudio.Core/GameRule/SpawnPositionSet.cs
index a68b1c8e..70961ab0 100644
--- a/PckStudio.Core/GameRule/SpawnPositionSet.cs
+++ b/PckStudio.Core/GameRule/SpawnPositionSet.cs
@@ -1,32 +1,20 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Numerics;
-using System.Text;
-using System.Threading.Tasks;
-using OMI.Formats.GameRule;
 
 namespace PckStudio.Core.GameRule
 {
     public sealed class SpawnPositionSet : AbstractGameRule
     {
+        public override string Name => "SpawnPositionSet";
+        public void AddSpawnPosition(int x, int y, int z, int xRot, int yRot) => AddRule(new UpdatePlayer(new Vector3(x, y, z), new Vector2(xRot, yRot)));
+        public void AddSpawnPosition(int x, int y, int z) => AddSpawnPosition(x, y, z, 0, 0);
+
         internal enum SpanPositionMethod
         {
             OnStart,
             OnRespawn
         }
-        private SpanPositionMethod _method;
 
-        internal SpawnPositionSet(SpanPositionMethod method) => _method = method;
-
-        public void AddSpawnPosition(int x, int y, int z, int xRot, int yRot) => AddRule(new UpdatePlayer(new Vector3(x, y, z), new Vector2(xRot, yRot)));
-        public void AddSpawnPosition(int x, int y, int z) => AddSpawnPosition(x, y, z, 0, 0);
-
-        protected override GameRuleFile.GameRule GetGameRule()
-        {
-            var gameRule = new GameRuleFile.GameRule("SpawnPositionSet");
-            gameRule.AddParameter(new GameRuleFile.IntParameter("method", (int)_method));
-            return gameRule;
-        }
+        internal SpawnPositionSet(SpanPositionMethod method) => AddParameter("method", (int)method);
     }
 }
diff --git a/PckStudio.Core/GameRule/UpdatePlayer.cs b/PckStudio.Core/GameRule/UpdatePlayer.cs
index 7919421b..04bbd870 100644
--- a/PckStudio.Core/GameRule/UpdatePlayer.cs
+++ b/PckStudio.Core/GameRule/UpdatePlayer.cs
@@ -1,35 +1,16 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Numerics;
-using System.Text;
-using System.Threading.Tasks;
-using OMI.Formats.GameRule;
 
 namespace PckStudio.Core.GameRule
 {
-    internal sealed class UpdatePlayer : AbstractGameRule
+    public sealed class UpdatePlayer : AbstractGameRule
     {
-        private Vector3 _spawn;
-        private Vector2 _rot;
+        public override string Name => "UpdatePlayer";
 
         public UpdatePlayer(Vector3 spawn, Vector2 rot)
         {
-            _spawn = spawn;
-            _rot = rot;
-        }
-
-        protected override GameRuleFile.GameRule GetGameRule()
-        {
-            var gameRule = new GameRuleFile.GameRule("UpdatePlayer");
-            gameRule.AddParameters(
-                new GameRuleFile.FloatParameter("x", _spawn.X),
-                new GameRuleFile.FloatParameter("y", _spawn.Y),
-                new GameRuleFile.FloatParameter("z", _spawn.Z),
-                new GameRuleFile.FloatParameter("xRot", _rot.X),
-                new GameRuleFile.FloatParameter("yRot", _rot.Y)
-                );
-            return gameRule;
+            AddParameter(spawn);
+            AddParameter(rot, suffix: "Rot");
         }
     }
 }
diff --git a/PckStudio.Core/GameRule/WorldPosition.cs b/PckStudio.Core/GameRule/WorldPosition.cs
index 10014e21..d902ea27 100644
--- a/PckStudio.Core/GameRule/WorldPosition.cs
+++ b/PckStudio.Core/GameRule/WorldPosition.cs
@@ -1,26 +1,14 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Numerics;
-using System.Text;
-using System.Threading.Tasks;
-using OMI.Formats.GameRule;
-
 namespace PckStudio.Core.GameRule
 {
-    internal sealed class WorldPosition(int x, int y, int z) : AbstractGameRule
+    internal sealed class WorldPosition : AbstractGameRule
     {
-        private Vector3 _pos = new Vector3(x, y, z);
-        
-        protected override GameRuleFile.GameRule GetGameRule()
+        public override string Name => "WorldPosition";
+
+        public WorldPosition(int x, int y, int z)
         {
-            var gameRule = new GameRuleFile.GameRule("WorldPosition");
-            gameRule.AddParameters(
-                new GameRuleFile.IntParameter("x", (int)_pos.X),
-                new GameRuleFile.IntParameter("y", (int)_pos.Y),
-                new GameRuleFile.IntParameter("z", (int)_pos.Z)
-                );
-            return gameRule;
+            AddParameter(new Vector3(x, y, z));
         }
     }
 }
diff --git a/PckStudio.Core/MapData.cs b/PckStudio.Core/MapData.cs
index e1d60a03..655c0a0c 100644
--- a/PckStudio.Core/MapData.cs
+++ b/PckStudio.Core/MapData.cs
@@ -4,7 +4,7 @@ using System.Drawing;
 using System.IO;
 using System.Numerics;
 using Cyotek.Data.Nbt;
-using OMI.Formats.GameRule;
+using PckStudio.Core.Extensions;
 using PckStudio.Core.GameRule;
 
 namespace PckStudio.Core
@@ -24,41 +24,45 @@ namespace PckStudio.Core
         Huge
     }
 
+#nullable enable
     public sealed class MapData
     {
         public string Name { get; }
-        public Image Thumbnail { get; }
+        public Image? Thumbnail { get; }
         public AbstractGameRule LevelRules { get; }
         internal AbstractGameRule Grf { get; }
         internal NamedData<byte[]> World { get; }
-
-        public MapData(string name, Image thumbnail, MiniGameId miniGame, MapSize mapSize, NamedData<byte[]> world)
+        
+        public MapData(string name, Image? thumbnail, NamedData<byte[]> world, MiniGameId miniGame = MiniGameId.None, MapSize mapSize = default)
         {
             Name = name;
             Thumbnail = thumbnail;
-            Grf = new RootGameRule();
+            World = world;
 
             var levelData = MapReader.OpenSave(new MemoryStream(world.Value))["level.dat"];
-            TagCompound levelDat = NbtDocument.LoadDocument(new MemoryStream(levelData)).DocumentRoot["Data"] as TagCompound;
-            Vector3 spawn = Vector3.Zero;
-            if (levelDat is not null)
-                spawn = new Vector3((int)levelDat["SpawnX"].GetValue(), (int)levelDat["SpawnX"].GetValue(), (int)levelDat["SpawnY"].GetValue());
-            
-            Grf.AddRule(new NamedRule("MapOptions",
-                new GameRuleFile.GameRuleParameter("seed", levelDat["RandomSeed"].GetValue().ToString()),
-                new GameRuleFile.FloatParameter("spawnX", spawn.X),
-                new GameRuleFile.FloatParameter("spawnY", spawn.Y),
-                new GameRuleFile.FloatParameter("spawnZ", spawn.Z),
-                new GameRuleFile.BoolParameter("flatworld", false),
-                new GameRuleFile.GameRuleParameter("baseSaveName", world.Name),
-                new GameRuleFile.IntParameter("mapSize", (int)mapSize),
-                new GameRuleFile.IntParameter("themeId", 0))
-                );
+            TagCompound? levelDat = NbtDocument.LoadDocument(new MemoryStream(levelData))!.DocumentRoot?["Data"] as TagCompound;
+            _ = levelDat ?? throw new NullReferenceException(nameof(levelDat));
+            Vector3 spawn = levelDat.GetVector3("Spawn");
 
-            LevelRules = GameRule.LevelRules.GetMiniGameLevelRules(miniGame);
+            var mapOptions = new NamedRule("MapOptions");
+            mapOptions.AddParameter("seed", levelDat["RandomSeed"].GetValue());
+            mapOptions.AddParameter(spawn, prefix: "spawn");
+            mapOptions.AddParameter("flatworld", false);
+            mapOptions.AddParameter("baseSaveName", world.Name);
+            if (miniGame > MiniGameId.None)
+            {
+                mapOptions.AddParameter("mapSize", (int)mapSize);
+                mapOptions.AddParameter("themeId", 0);
+            }
+
+            Grf = new RootGameRule();
+
+            Grf.AddRule(mapOptions);
+
+            LevelRules = miniGame > MiniGameId.None ? GameRule.LevelRules.GetMiniGameLevelRules(miniGame) : GameRule.LevelRules.GetDefault(spawn, Vector2.Zero);
             Grf.AddRule(LevelRules);
 
-            World = world;
         }
+#nullable disable
     }
-}
+}
\ No newline at end of file