diff --git a/PckStudio.Core/MapData.cs b/PckStudio.Core/MapData.cs
index 37370f02..e1d60a03 100644
--- a/PckStudio.Core/MapData.cs
+++ b/PckStudio.Core/MapData.cs
@@ -1,5 +1,11 @@
-using System.Drawing;
+using System;
+using System.Diagnostics;
+using System.Drawing;
+using System.IO;
+using System.Numerics;
+using Cyotek.Data.Nbt;
 using OMI.Formats.GameRule;
+using PckStudio.Core.GameRule;
 
 namespace PckStudio.Core
 {
@@ -22,23 +28,31 @@ namespace PckStudio.Core
     {
         public string Name { get; }
         public Image Thumbnail { get; }
-        public GameRuleFile Grf { get; }
-        public GameRuleFile.GameRule LevelRules { get; }
-        public NamedData<byte[]> World { 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)
         {
             Name = name;
             Thumbnail = thumbnail;
-            Grf = new GameRuleFile();
-            Grf.AddRule("MapOptions",
-                new GameRuleFile.IntParameter("seed", 0),
-                new GameRuleFile.IntParameter("spawnX", 0),
-                new GameRuleFile.IntParameter("spawnY", 0),
-                new GameRuleFile.IntParameter("spawnZ", 0),
+            Grf = new RootGameRule();
+
+            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)
+                new GameRuleFile.IntParameter("themeId", 0))
                 );
 
             LevelRules = GameRule.LevelRules.GetMiniGameLevelRules(miniGame);
diff --git a/PckStudio.Core/MapReader.cs b/PckStudio.Core/MapReader.cs
new file mode 100644
index 00000000..6f2d8411
--- /dev/null
+++ b/PckStudio.Core/MapReader.cs
@@ -0,0 +1,41 @@
+using System.Collections.Generic;
+using System.IO;
+using ICSharpCode.SharpZipLib.Zip.Compression.Streams;
+using OMI;
+
+namespace PckStudio.Core
+{
+    public class MapReader
+    {
+        public static IDictionary<string, byte[]> OpenSave(Stream stream)
+        {
+            EndiannessAwareBinaryReader reader = new EndiannessAwareBinaryReader(stream, ByteOrder.BigEndian);
+            _ = reader.ReadInt32();
+            int bufferSize = reader.ReadInt32();
+            byte[] buffer = new byte[bufferSize];
+            using Stream decompStream = new InflaterInputStream(stream);
+            decompStream.Read(buffer, 0, bufferSize);
+            reader = new EndiannessAwareBinaryReader(new MemoryStream(buffer), System.Text.Encoding.BigEndianUnicode, ByteOrder.BigEndian);
+
+            int fileStartOffset = reader.ReadInt32();
+            int fileCount = reader.ReadInt32();
+            reader.BaseStream.Seek(fileStartOffset, SeekOrigin.Begin);
+            Dictionary<string, byte[]> res = new Dictionary<string, byte[]>();
+            for (int i = 0; i < fileCount; i++)
+            {
+                string path = reader.ReadString(64).Replace('\\', '/');
+                int size = reader.ReadInt32();
+                int offset = reader.ReadInt32();
+                long timestemp = reader.ReadInt64();
+
+                long origin = reader.BaseStream.Position;
+                reader.BaseStream.Seek(offset, SeekOrigin.Begin);
+                byte[] data = reader.ReadBytes(size);
+                reader.BaseStream.Seek(origin, SeekOrigin.Begin);
+
+                res.Add(path, data);
+            }
+            return res;
+        }
+    }
+}
diff --git a/PckStudio.Core/PckStudio.Core.csproj b/PckStudio.Core/PckStudio.Core.csproj
index f48ed240..569565b7 100644
--- a/PckStudio.Core/PckStudio.Core.csproj
+++ b/PckStudio.Core/PckStudio.Core.csproj
@@ -104,8 +104,10 @@
     <Compile Include="GameRule\DistributeItems.cs" />
     <Compile Include="GameRule\LevelRules.cs" />
     <Compile Include="GameRule\NamedArea.cs" />
+    <Compile Include="GameRule\NamedRule.cs" />
     <Compile Include="GameRule\OnGameStartSpawnPositions.cs" />
     <Compile Include="GameRule\OnInitialiseWorld.cs" />
+    <Compile Include="GameRule\RootGameRule.cs" />
     <Compile Include="GameRule\SpawnPositionSet.cs" />
     <Compile Include="GameRule\UpdatePlayer.cs" />
     <Compile Include="GameRule\WorldPosition.cs" />
@@ -142,6 +144,7 @@
     <Compile Include="Json\TileInfo.cs" />
     <Compile Include="Json\UpdateInformation.cs" />
     <Compile Include="MapData.cs" />
+    <Compile Include="MapReader.cs" />
     <Compile Include="Misc\FileCacher.cs" />
     <Compile Include="Misc\OpenFolderDialog.cs" />
     <Compile Include="NamedData.cs" />
@@ -170,6 +173,9 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="AnimatedGif" Version="1.0.5" />
+    <PackageReference Include="Cyotek.Data.Nbt">
+      <Version>3.1.1</Version>
+    </PackageReference>
     <PackageReference Include="DiscordRichPresence" Version="1.6.1.70" />
     <PackageReference Include="Newtonsoft.Json">
       <Version>13.0.3</Version>