diff --git a/.gitignore b/.gitignore
index 6c789ad..a42fb76 100644
--- a/.gitignore
+++ b/.gitignore
@@ -404,4 +404,6 @@ build/
 dist/
 *.spec
 
-# End of https://www.toptal.com/developers/gitignore/api/csharp
\ No newline at end of file
+# End of https://www.toptal.com/developers/gitignore/api/csharp
+
+run.bat
\ No newline at end of file
diff --git a/PolyMod.csproj b/PolyMod.csproj
index 22b404b..4f6484f 100644
--- a/PolyMod.csproj
+++ b/PolyMod.csproj
@@ -11,7 +11,7 @@
         </RestoreAdditionalProjectSources>
         <Configurations>IL2CPP</Configurations>
         <RootNamespace>PolyMod</RootNamespace>
-        <Version>1.2.11</Version>
+        <Version>1.3.0-pre</Version>
         <PolytopiaVersion>2.16.4.15698</PolytopiaVersion>
         <Authors>PolyModdingTeam</Authors>
         <Description>The Battle of Polytopia's mod loader.</Description>
diff --git a/src/Multiplayer/Client.cs b/src/Multiplayer/Client.cs
new file mode 100644
index 0000000..4ff1a93
--- /dev/null
+++ b/src/Multiplayer/Client.cs
@@ -0,0 +1,379 @@
+using HarmonyLib;
+using Il2CppMicrosoft.AspNetCore.SignalR.Client;
+using PolyMod.Multiplayer.ViewModels;
+using Polytopia.Data;
+using PolytopiaBackendBase;
+using PolytopiaBackendBase.Common;
+using PolytopiaBackendBase.Game;
+using PolytopiaBackendBase.Game.BindingModels;
+using UnityEngine;
+using Newtonsoft.Json;
+
+namespace PolyMod.Multiplayer;
+
+public static class Client
+{
+    internal const string DEFAULT_SERVER_URL = "https://dev.polydystopia.xyz";
+    internal const string LOCAL_SERVER_URL = "http://localhost:5051/";
+    private const string GldMarker = "##GLD:";
+    internal static bool allowGldMods = false;
+
+    // Cache parsed GLD by game Seed to handle rewinds/reloads
+    private static readonly Dictionary<int, GameLogicData> _gldCache = new();
+    private static readonly Dictionary<int, int> _versionCache = new(); // Seed -> modGldVersion
+
+    internal static void Init()
+    {
+        Harmony.CreateAndPatchAll(typeof(Client));
+        BuildConfig buildConfig = BuildConfigHelper.GetSelectedBuildConfig();
+        buildConfig.buildServerURL = BuildServerURL.Custom;
+        buildConfig.customServerURL = Plugin.config.backendUrl;
+
+        Plugin.logger.LogInfo($"Multiplayer> Server URL set to: {Plugin.config.backendUrl}");
+        Plugin.logger.LogInfo("Multiplayer> GLD patches applied");
+    }
+
+    [HarmonyPostfix]
+    [HarmonyPatch(typeof(MultiplayerScreen), nameof(MultiplayerScreen.Show))]
+    public static void MultiplayerScreen_Show(MultiplayerScreen __instance)
+    {
+        __instance.multiplayerSelectionScreen.TournamentsButton.gameObject.SetActive(false);
+    }
+
+    [HarmonyPostfix]
+    [HarmonyPatch(typeof(StartScreen), nameof(StartScreen.Start))]
+    private static void StartScreen_Start(StartScreen __instance)
+    {
+        __instance.highscoreButton.gameObject.SetActive(false);
+        __instance.weeklyChallengesButton.gameObject.SetActive(false);
+    }
+
+    [HarmonyPostfix]
+    [HarmonyPatch(typeof(SystemInfo), nameof(SystemInfo.deviceUniqueIdentifier), MethodType.Getter)]
+    public static void SteamClient_get_SteamId(ref string  __result)
+    {
+        if (Plugin.config.overrideDeviceId != string.Empty)
+        {
+            __result = Plugin.config.overrideDeviceId;
+        }
+    }
+
+
+    /// <summary>
+    /// After GameState deserialization, check for trailing GLD version ID and set mockedGameLogicData.
+    /// The server appends "##GLD:" + modGldVersion (int) after the normal serialized data.
+    /// </summary>
+    [HarmonyPostfix]
+    [HarmonyPatch(typeof(GameState), nameof(GameState.Deserialize))]
+    private static void Deserialize_Postfix(GameState __instance, BinaryReader __0)
+    {
+        if(!allowGldMods) return;
+
+        Plugin.logger?.LogDebug("Deserialize_Postfix: Entered");
+
+        try
+        {
+            var reader = __0;
+            if (reader == null)
+            {
+                Plugin.logger?.LogWarning("Deserialize_Postfix: reader is null");
+                return;
+            }
+
+            var position = reader.BaseStream.Position;
+            var length = reader.BaseStream.Length;
+            var remaining = length - position;
+
+            Plugin.logger?.LogDebug($"Deserialize_Postfix: Stream position={position}, length={length}, remaining={remaining}");
+
+            // Check if there's more data after normal deserialization
+            if (position >= length)
+            {
+                Plugin.logger?.LogDebug("Deserialize_Postfix: No trailing data (position >= length)");
+
+                var sd = __instance.Seed;
+                if (_gldCache.TryGetValue(sd, out var cachedGld))
+                {
+                    __instance.mockedGameLogicData = cachedGld;
+                    var cachedVersion = _versionCache.GetValueOrDefault(sd, -1);
+                    Plugin.logger?.LogInfo($"Deserialize_Postfix: Applied cached GLD for Seed={sd}, ModGldVersion={cachedVersion}");
+                }
+                return;
+            }
+
+            Plugin.logger?.LogDebug($"Deserialize_Postfix: Found {remaining} bytes of trailing data, attempting to read marker");
+
+            var marker = reader.ReadString();
+            Plugin.logger?.LogDebug($"Deserialize_Postfix: Read marker string: '{marker}'");
+
+            if (marker != GldMarker)
+            {
+                Plugin.logger?.LogDebug($"Deserialize_Postfix: Marker mismatch - expected '{GldMarker}', got '{marker}'");
+                return;
+            }
+
+            Plugin.logger?.LogInfo($"Deserialize_Postfix: Found GLD marker '{GldMarker}'");
+
+            var modGldVersion = reader.ReadInt32();
+            Plugin.logger?.LogInfo($"Deserialize_Postfix: Found embedded ModGldVersion: {modGldVersion}");
+
+            Plugin.logger?.LogDebug($"Deserialize_Postfix: Fetching GLD from server for version {modGldVersion}");
+            var gldJson = FetchGldById(modGldVersion);
+            if (string.IsNullOrEmpty(gldJson))
+            {
+                Plugin.logger?.LogError($"Deserialize_Postfix: Failed to fetch GLD for ModGldVersion: {modGldVersion}");
+                return;
+            }
+
+            Plugin.logger?.LogDebug($"Deserialize_Postfix: Parsing GLD JSON ({gldJson.Length} chars)");
+
+            var customGld = new GameLogicData();
+            customGld.Parse(gldJson);
+            __instance.mockedGameLogicData = customGld;
+
+            // Cache for subsequent deserializations (rewinds, reloads)
+            var seed = __instance.Seed;
+            _gldCache[seed] = customGld;
+            _versionCache[seed] = modGldVersion;
+
+            Plugin.logger?.LogInfo($"Deserialize_Postfix: Successfully set mockedGameLogicData from ModGldVersion: {modGldVersion}, cached for Seed={seed}");
+        }
+        catch (EndOfStreamException)
+        {
+            Plugin.logger?.LogDebug("Deserialize_Postfix: EndOfStreamException - no trailing data");
+        }
+        catch (Exception ex)
+        {
+            Plugin.logger?.LogError($"Deserialize_Postfix: Exception: {ex.GetType().Name}: {ex.Message}");
+            Plugin.logger?.LogDebug($"Deserialize_Postfix: Stack trace: {ex.StackTrace}");
+        }
+    }
+
+    /// <summary>
+    /// Fetch GLD from server using ModGldVersion ID
+    /// </summary>
+    private static string? FetchGldById(int modGldVersion)
+    {
+        if(!allowGldMods) return null;
+        try
+        {
+            using var client = new HttpClient();
+            var url = $"{Plugin.config.backendUrl.TrimEnd('/')}/api/mods/gld/{modGldVersion}";
+            Plugin.logger?.LogDebug($"FetchGldById: Requesting URL: {url}");
+
+            var response = client.GetAsync(url).Result;
+            Plugin.logger?.LogDebug($"FetchGldById: Response status: {response.StatusCode}");
+
+            if (response.IsSuccessStatusCode)
+            {
+                var gld = response.Content.ReadAsStringAsync().Result;
+                Plugin.logger?.LogInfo($"FetchGldById: Successfully fetched mod GLD ({gld.Length} chars)");
+                return gld;
+            }
+
+            var errorContent = response.Content.ReadAsStringAsync().Result;
+            Plugin.logger?.LogError($"FetchGldById: Failed with status {response.StatusCode}: {errorContent}");
+        }
+        catch (Exception ex)
+        {
+            Plugin.logger?.LogError($"FetchGldById: Exception: {ex.GetType().Name}: {ex.Message}");
+            if (ex.InnerException != null)
+            {
+                Plugin.logger?.LogError($"FetchGldById: Inner exception: {ex.InnerException.Message}");
+            }
+        }
+        return null;
+    }
+
+    [HarmonyPrefix]
+    [HarmonyPatch(typeof(BackendAdapter), nameof(BackendAdapter.StartLobbyGame))]
+    private static bool BackendAdapter_StartLobbyGame_Modded(
+        ref Il2CppSystem.Threading.Tasks.Task<ServerResponse<LobbyGameViewModel>> __result,
+        BackendAdapter __instance,
+        StartLobbyBindingModel model)
+    {
+        Plugin.logger.LogInfo("Multiplayer> BackendAdapter_StartLobbyGame_Modded");
+        var taskCompletionSource = new Il2CppSystem.Threading.Tasks.TaskCompletionSource<ServerResponse<LobbyGameViewModel>>();
+
+        _ = HandleStartLobbyGameModded(taskCompletionSource, __instance, model);
+
+        __result = taskCompletionSource.Task;
+
+        return false;
+    }
+
+    private static async System.Threading.Tasks.Task HandleStartLobbyGameModded(
+        Il2CppSystem.Threading.Tasks.TaskCompletionSource<ServerResponse<LobbyGameViewModel>> tcs,
+        BackendAdapter instance,
+        StartLobbyBindingModel model)
+    {
+        try
+        {
+            var lobbyResponse = await PolytopiaBackendAdapter.Instance.GetLobby(new GetLobbyBindingModel
+            {
+                LobbyId = model.LobbyId
+            });
+
+            Plugin.logger.LogInfo($"Multiplayer> Lobby processed {lobbyResponse.Success}");
+            LobbyGameViewModel lobbyGameViewModel = lobbyResponse.Data;
+            Plugin.logger.LogInfo("Multiplayer> Lobby received");
+
+            (byte[] serializedGameState, string gameSettingsJson) = CreateMultiplayerGame(
+                lobbyGameViewModel,
+                VersionManager.GameVersion,
+                VersionManager.GameLogicDataVersion
+            );
+
+            Plugin.logger.LogInfo("Multiplayer> GameState and Settiings created");
+
+            var setupGameDataViewModel = new SetupGameDataViewModel
+            {
+                lobbyId = lobbyGameViewModel.Id.ToString(),
+                serializedGameState = serializedGameState,
+                gameSettingsJson = gameSettingsJson
+            };
+
+            var setupData = System.Text.Json.JsonSerializer.Serialize(setupGameDataViewModel);
+
+            var serverResponse = await instance.HubConnection.InvokeAsync<ServerResponse<LobbyGameViewModel>>(
+                "StartLobbyGameModded",
+                setupData,
+                Il2CppSystem.Threading.CancellationToken.None
+            );
+            Plugin.logger.LogInfo("Multiplayer> Invoked StartLobbyGameModded");
+            tcs.SetResult(serverResponse);
+        }
+        catch (Exception ex)
+        {
+            Plugin.logger.LogError("Multiplayer> Error during HandleStartLobbyGameModded: " + ex.Message);
+            tcs.SetException(new Il2CppSystem.Exception(ex.Message));
+        }
+    }
+
+    public static (byte[] serializedGameState, string gameSettingsJson) CreateMultiplayerGame(LobbyGameViewModel lobby,
+        int gameVersion, int gameLogicVersion)
+    {
+        var lobbyMapSize = lobby.MapSize;
+        var settings = new GameSettings();
+        settings.ApplyLobbySettings(lobby);
+        if (settings.LiveGamePreset)
+        {
+            settings.SetLiveModePreset();
+        }
+        foreach (var participatorViewModel in lobby.Participators)
+        {
+            var humanPlayer = new PlayerData
+            {
+                type = PlayerDataType.LocalUser,
+                state = PlayerDataFriendshipState.Accepted,
+                knownTribe = true,
+                tribe = (TribeType)participatorViewModel.SelectedTribe,
+                tribeMix = (TribeType)participatorViewModel.SelectedTribe,
+                skinType = (SkinType)participatorViewModel.SelectedTribeSkin,
+                defaultName = participatorViewModel.GetNameInternal()
+            };
+            humanPlayer.profile.id = participatorViewModel.UserId;
+            humanPlayer.profile.SetName(participatorViewModel.GetNameInternal());
+            SerializationHelpers.FromByteArray<AvatarState>(participatorViewModel.AvatarStateData, out var avatarState);
+            humanPlayer.profile.avatarState = avatarState;
+
+            settings.AddPlayer(humanPlayer);
+        }
+
+        foreach (var botDifficulty in lobby.Bots)
+        {
+            var botGuid = Il2CppSystem.Guid.NewGuid();
+
+            var botPlayer = new PlayerData
+            {
+                type = PlayerDataType.Bot,
+                state = PlayerDataFriendshipState.Accepted,
+                knownTribe = true,
+                tribe = Enum.GetValues<TribeType>().Where(t => t != TribeType.None)
+                    .OrderBy(x => Il2CppSystem.Guid.NewGuid()).First()
+            };
+            ;
+            botPlayer.botDifficulty = (BotDifficulty)botDifficulty;
+            botPlayer.skinType = SkinType.Default;
+            botPlayer.defaultName = "Bot" + botGuid;
+            botPlayer.profile.id = botGuid;
+
+            settings.AddPlayer(botPlayer);
+        }
+
+        GameState gameState = new GameState()
+        {
+            Version = gameVersion,
+            Settings = settings,
+            PlayerStates = new Il2CppSystem.Collections.Generic.List<PlayerState>()
+        };
+
+        for (int index = 0; index < settings.GetPlayerCount(); ++index)
+        {
+            PlayerData player = settings.GetPlayer(index);
+            if (player.type != PlayerDataType.Bot)
+            {
+                var nullableGuid = new Il2CppSystem.Nullable<Il2CppSystem.Guid>(player.profile.id);
+                if (!nullableGuid.HasValue)
+                {
+                    throw new Exception("GUID was not set properly!");
+                }
+                PlayerState playerState = new PlayerState()
+                {
+                    Id = (byte)(index + 1),
+                    AccountId = nullableGuid,
+                    AutoPlay = player.type == PlayerDataType.Bot,
+                    UserName = player.GetNameInternal(),
+                    tribe = player.tribe,
+                    tribeMix = player.tribeMix,
+                    hasChosenTribe = true,
+                    skinType = player.skinType
+                };
+                gameState.PlayerStates.Add(playerState);
+                Plugin.logger.LogInfo($"Multiplayer> Created player: {playerState}");
+            }
+            else
+            {
+                GameStateUtils.AddAIOpponent(gameState, GameStateUtils.GetRandomPickableTribe(gameState),
+                    GameSettings.HandicapFromDifficulty(player.botDifficulty), player.skinType);
+            }
+        }
+
+        GameStateUtils.SetPlayerColors(gameState);
+        GameStateUtils.AddNaturePlayer(gameState);
+
+        Plugin.logger.LogInfo("Multiplayer> Creating world...");
+
+        ushort num = (ushort)Math.Max(lobbyMapSize,
+            (int)MapDataExtensions.GetMinimumMapSize(gameState.PlayerCount));
+        gameState.Map = new MapData(num, num);
+        MapGeneratorSettings generatorSettings = settings.GetMapGeneratorSettings();
+        new MapGenerator().Generate(gameState, generatorSettings);
+
+        Plugin.logger.LogInfo($"Multiplayer> Creating initial state for {gameState.PlayerCount} players...");
+
+        foreach (PlayerState player in gameState.PlayerStates)
+        {
+            foreach (PlayerState otherPlayer in gameState.PlayerStates)
+                player.aggressions[otherPlayer.Id] = 0;
+
+            if (player.Id != byte.MaxValue && gameState.GameLogicData.TryGetData(player.tribe, out TribeData tribeData))
+            {
+                player.Currency = tribeData.startingStars;
+                TileData tile = gameState.Map.GetTile(player.startTile);
+                UnitState unitState = ActionUtils.TrainUnitScored(gameState, player, tile, tribeData.startingUnit);
+                unitState.attacked = false;
+                unitState.moved = false;
+            }
+        }
+
+        Plugin.logger.LogInfo("Multiplayer> Session created successfully");
+
+        gameState.CommandStack.Add((CommandBase)new StartMatchCommand((byte)1));
+
+        var serializedGameState = SerializationHelpers.ToByteArray(gameState, gameState.Version);
+
+        return (serializedGameState,
+            JsonConvert.SerializeObject(gameState.Settings));
+    }
+}
diff --git a/src/Multiplayer/ViewModels/IMonoServerResponseData.cs b/src/Multiplayer/ViewModels/IMonoServerResponseData.cs
new file mode 100644
index 0000000..3b0a835
--- /dev/null
+++ b/src/Multiplayer/ViewModels/IMonoServerResponseData.cs
@@ -0,0 +1,5 @@
+namespace PolyMod.Multiplayer.ViewModels;
+
+public interface IMonoServerResponseData
+{
+}
\ No newline at end of file
diff --git a/src/Multiplayer/ViewModels/SetupGameDataViewModel.cs b/src/Multiplayer/ViewModels/SetupGameDataViewModel.cs
new file mode 100644
index 0000000..68f43f1
--- /dev/null
+++ b/src/Multiplayer/ViewModels/SetupGameDataViewModel.cs
@@ -0,0 +1,10 @@
+
+namespace PolyMod.Multiplayer.ViewModels;
+public class SetupGameDataViewModel : IMonoServerResponseData
+{
+    public string lobbyId { get; set; }
+
+	public byte[] serializedGameState { get; set; }
+
+	public string gameSettingsJson { get; set; }
+}
\ No newline at end of file
diff --git a/src/Plugin.cs b/src/Plugin.cs
index 96ae942..924944c 100644
--- a/src/Plugin.cs
+++ b/src/Plugin.cs
@@ -24,7 +24,9 @@ internal record PolyConfig(
 		bool debug = false,
 		bool autoUpdate = true,
 		bool updatePrerelease = false,
-		bool allowUnsafeIndexes = false
+		bool allowUnsafeIndexes = false,
+		string backendUrl = Multiplayer.Client.DEFAULT_SERVER_URL,
+		string overrideDeviceId = ""
 	);
 
 	/// <summary>
@@ -132,6 +134,7 @@ public override void Load()
 		Hub.Init();
 
 		Main.Init();
+		Multiplayer.Client.Init();
 	}
 
 	/// <summary>