fix(lobby): wire OnConfirm to POST /api/game/start, save game_id to PlayerPrefs

- OnConfirm() now calls ApiClient.PostGameStart() with 4-seat config
- On success: saves BattleSeats + GameId + WsUrl to PlayerPrefs,
  loads Battleground scene
- On failure: shows inline error label (red), re-enables Confirm button
- Added StartGameRequest/Response POCOs matching routes/game.py schema
- Added _errorLabel [SerializeField] for user-facing error feedback

lab_api.py

@@ -42,6 +42,7 @@ from routes.deckgen import router as deckgen_router
 from routes.coach import router as coach_router, init_coach_service
 from routes.ml import router as ml_router
 from routes.ws_game import router as ws_game_router
+from routes.game import router as game_router
 
 log = logging.getLogger("commander_ai_lab.api")
 
@@ -50,7 +51,7 @@ _allowed = os.environ.get("ALLOWED_ORIGINS", _DEFAULT_ORIGINS)
 allowed_origins = [o.strip() for o in _allowed.split(",") if o.strip()]
 
 
-# ── Lifespan (replaces deprecated @app.on_event) ───────────────────────────────────────
+# ── Lifespan (replaces deprecated @app.on_event) ────────────────────────────────────────────────────────
 @asynccontextmanager
 async def _lifespan(application: FastAPI):
     # ──── STARTUP ────
@@ -113,7 +114,7 @@ async def _lifespan(application: FastAPI):
     await async_close_db()
 
 
-# ── App ───────────────────────────────────────────────────────────────────────
+# ── App ─────────────────────────────────────────────────────────────────────────────
 app = FastAPI(title="Commander AI Lab API", version="3.0.0", lifespan=_lifespan)
 app.add_middleware(
     CORSMiddleware,
@@ -135,9 +136,10 @@ app.include_router(deckgen_router)
 app.include_router(coach_router)
 app.include_router(ws_game_router)
 app.include_router(ml_router)
+app.include_router(game_router)   # live game session routes
 
 
-# ── API endpoints ────────────────────────────────────────────────────────────────
+# ── API endpoints ─────────────────────────────────────────────────────────────────────────────
 # NOTE: all @app.get routes MUST be registered before app.mount() calls.
 # Once StaticFiles is mounted at "/", it registers a wildcard catch-all that
 # shadows any routes added after it.
@@ -147,7 +149,7 @@ async def health_check():
     """Health check endpoint for load balancers and Unity client polling."""
     return {"status": "ok"}
 
-# ── Static UI (MUST come after all @app.get routes) ────────────────────────────
+# ── Static UI (MUST come after all @app.get routes) ──────────────────────────────────────────
 from pathlib import Path as _Path
 _legacy_ui_dir = _Path(__file__).parent / "ui"
 _spa_dir = _Path(__file__).parent / "frontend" / "commander-ai-lab-ui" / "dist"
@@ -168,7 +170,7 @@ elif _spa_dir.exists():
         return FileResponse(str(_spa_dir / "index.html"))
 
 
-# ── Argument parsing + auto-detection helpers ───────────────────────────────────────
+# ── Argument parsing + auto-detection helpers ────────────────────────────────────────────────────────
 def _parse_args():
     p = argparse.ArgumentParser(description="Commander AI Lab API Server")
     p.add_argument("--forge-jar", default=os.environ.get("FORGE_JAR", ""))

routes/game.py

@@ -0,0 +1,209 @@
+"""Live game session routes.
+
+Endpoints:
+  POST /api/game/start   — create a new live game session (called by LobbySetupModal)
+  POST /api/game/action  — submit a human player action   (called by HumanActionBar)
+"""
+from __future__ import annotations
+
+import logging
+import uuid
+from typing import List, Optional
+
+from fastapi import APIRouter, HTTPException
+from pydantic import BaseModel, Field
+
+log = logging.getLogger("routes.game")
+
+router = APIRouter(tags=["game"])
+
+
+# ───────────────────────────────────────────────────────────────
+# Request / Response models
+# ───────────────────────────────────────────────────────────────
+
+class SeatConfig(BaseModel):
+    seat_index: int = 0
+    seat_type: str = "AI"          # "Human" | "AI Aggro" | "AI Control" | "AI Combo" | "AI Political"
+    deck_name: str = ""
+    player_name: str = ""
+
+
+class StartGameRequest(BaseModel):
+    seats: List[SeatConfig] = Field(default_factory=list)
+
+
+class StartGameResponse(BaseModel):
+    game_id: str
+    status: str = "started"
+    ws_url: str
+
+
+class GameActionRequest(BaseModel):
+    game_id: str
+    seat: int = 0
+    action: str                    # "pass_priority" | "end_turn" | "declare_attackers" |
+                                   # "declare_blockers" | "select_target"
+    target_id: Optional[str] = None
+    extra: dict = Field(default_factory=dict)
+
+
+class GameActionResponse(BaseModel):
+    status: str = "ok"
+    game_id: str
+    action: str
+
+
+# ───────────────────────────────────────────────────────────────
+# In-memory session store  (replace with DB / Redis for persistence)
+# ───────────────────────────────────────────────────────────────
+
+# { game_id: { "seats": [...], "status": "active" | "ended", "pending_actions": [...] } }
+_sessions: dict[str, dict] = {}
+
+
+# ───────────────────────────────────────────────────────────────
+# POST /api/game/start
+# ───────────────────────────────────────────────────────────────
+
+@router.post("/api/game/start", response_model=StartGameResponse)
+async def start_game(req: StartGameRequest):
+    """Create a new live game session.
+
+    Called by Unity's LobbySetupModal after the player configures seats.
+    Returns a game_id that Unity uses to connect to the WebSocket at
+    /ws/game/{game_id}.
+
+    TODO: Wire Forge engine launch here once the IPC layer is ready.
+    For now, creates a session record and returns the game_id so Unity
+    can connect and receive state pushes from the Forge IPC client.
+    """
+    if not req.seats:
+        raise HTTPException(status_code=400, detail="At least one seat is required.")
+
+    game_id = uuid.uuid4().hex
+
+    _sessions[game_id] = {
+        "game_id": game_id,
+        "seats": [s.dict() for s in req.seats],
+        "status": "active",
+        "pending_actions": [],
+    }
+
+    log.info(
+        "Game session created: game_id=%s seats=%d",
+        game_id,
+        len(req.seats),
+    )
+
+    return StartGameResponse(
+        game_id=game_id,
+        status="started",
+        ws_url=f"/ws/game/{game_id}",
+    )
+
+
+# ───────────────────────────────────────────────────────────────
+# POST /api/game/action
+# ───────────────────────────────────────────────────────────────
+
+@router.post("/api/game/action", response_model=GameActionResponse)
+async def game_action(req: GameActionRequest):
+    """Submit a human player action during a live game.
+
+    Called by Unity's HumanActionBar when seat 0 (human) has priority.
+    The action is queued in the session's pending_actions list, where
+    the Forge IPC polling loop will pick it up.
+
+    Valid actions:
+      pass_priority     — pass priority to the next player
+      end_turn          — end the current turn
+      declare_attackers — declare attacking creatures
+      declare_blockers  — declare blocking creatures
+      select_target     — select a target (requires target_id)
+    """
+    valid_actions = {
+        "pass_priority", "end_turn",
+        "declare_attackers", "declare_blockers",
+        "select_target",
+    }
+
+    if req.action not in valid_actions:
+        raise HTTPException(
+            status_code=400,
+            detail=f"Unknown action '{req.action}'. Valid: {sorted(valid_actions)}",
+        )
+
+    if req.action == "select_target" and not req.target_id:
+        raise HTTPException(
+            status_code=400,
+            detail="select_target requires a target_id.",
+        )
+
+    session = _sessions.get(req.game_id)
+    if session is None:
+        raise HTTPException(
+            status_code=404,
+            detail=f"Game session '{req.game_id}' not found.",
+        )
+
+    if session["status"] != "active":
+        raise HTTPException(
+            status_code=409,
+            detail=f"Game session '{req.game_id}' is not active (status={session['status']}).",
+        )
+
+    action_record = {
+        "seat": req.seat,
+        "action": req.action,
+        "target_id": req.target_id,
+        "extra": req.extra,
+    }
+    session["pending_actions"].append(action_record)
+
+    log.info(
+        "Action queued: game_id=%s seat=%d action=%s",
+        req.game_id, req.seat, req.action,
+    )
+
+    return GameActionResponse(
+        status="ok",
+        game_id=req.game_id,
+        action=req.action,
+    )
+
+
+# ───────────────────────────────────────────────────────────────
+# GET /api/game/{game_id}/actions  (Forge IPC polling endpoint)
+# ───────────────────────────────────────────────────────────────
+
+@router.get("/api/game/{game_id}/actions")
+async def poll_actions(game_id: str):
+    """Drain and return all pending human actions for a game session.
+
+    Called by the Forge IPC polling loop to consume human player decisions.
+    Clears the queue on each call (consume-once semantics).
+    """
+    session = _sessions.get(game_id)
+    if session is None:
+        raise HTTPException(status_code=404, detail=f"Game session '{game_id}' not found.")
+
+    actions = session["pending_actions"].copy()
+    session["pending_actions"].clear()
+    return {"game_id": game_id, "actions": actions}
+
+
+# ───────────────────────────────────────────────────────────────
+# GET /api/game/sessions  (debug)
+# ───────────────────────────────────────────────────────────────
+
+@router.get("/api/game/sessions")
+async def list_sessions():
+    """List active game sessions (debug endpoint)."""
+    return {
+        "count": len(_sessions),
+        "sessions": [
+            {"game_id": gid, "status": s["status"], "seats": len(s["seats"])}
+            for gid, s in _sessions.items()
+        ],
+    }

unity-client/Assets/Scripts/Models/CardModel.cs

@@ -33,6 +33,24 @@ namespace CommanderAILab.Models
         [JsonProperty("roles")] public List<string> roles;
         [JsonProperty("source")] public string source;
 
+        // ── Battleground runtime state (not serialized to JSON) ───────────────
+        [NonSerialized] public bool isTapped;
+        [NonSerialized] public bool isSummoningSick;
+        [NonSerialized] public int ownerSeat = -1;
+        [NonSerialized] public BattleZone currentZone = BattleZone.Library;
+        [NonSerialized] public Dictionary<string, int> counters = new();
+
         public override string ToString() => $"{name} ({manaCost}) [{typeLine}]";
     }
+
+    public enum BattleZone
+    {
+        Library,
+        Hand,
+        Battlefield,
+        Graveyard,
+        Exile,
+        CommandZone,
+        Stack
+    }
 }

unity-client/Assets/Scripts/Models/GameState.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+using Newtonsoft.Json;
+using CommanderAILab.UI;
+
+namespace CommanderAILab.Models
+{
+    /// <summary>Full live game state snapshot pushed by the server on state_update events.</summary>
+    [Serializable]
+    public class GameState
+    {
+        [JsonProperty("seats")]       public List<SeatState> seats;
+        [JsonProperty("active_seat")] public int activeSeat;
+        [JsonProperty("turn_number")] public int turnNumber;
+        [JsonProperty("phase")]       public string phase;
+        [JsonProperty("stack")]       public List<StackZoneController.StackItem> stack;
+    }
+
+    /// <summary>Per-seat state within a GameState snapshot.</summary>
+    [Serializable]
+    public class SeatState
+    {
+        [JsonProperty("seat_index")]           public int seatIndex;
+        [JsonProperty("player_name")]          public string playerName;
+        [JsonProperty("life")]                 public int life;
+        [JsonProperty("hand")]                 public List<CardModel> hand;
+        [JsonProperty("battlefield")]          public List<CardModel> battlefield;
+        [JsonProperty("graveyard")]            public List<CardModel> graveyard;
+        [JsonProperty("exile")]                public List<CardModel> exile;
+        [JsonProperty("commander")]            public CardModel commander;
+        [JsonProperty("commander_cast_count")] public int commanderCastCount;
+        /// <summary>Cumulative commander damage received from each seat index (length 4).</summary>
+        [JsonProperty("commander_damage_from")] public int[] commanderDamageFrom;
+        [JsonProperty("poison_counters")]      public int poisonCounters;
+        [JsonProperty("mana_pool")]            public Dictionary<string, int> manaPool;
+        [JsonProperty("is_eliminated")]        public bool isEliminated;
+    }
+}

unity-client/Assets/Scripts/Models/TokenModel.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using Newtonsoft.Json;
+
+namespace CommanderAILab.Models
+{
+    /// <summary>Runtime data model for a token on the battlefield.</summary>
+    [Serializable]
+    public class TokenModel
+    {
+        public string id;
+        public string name;
+        public string power;
+        public string toughness;
+        /// <summary>Single letter: W U B R G C</summary>
+        public string colorCode = "C";
+        public int ownerSeat;
+        public int qty = 1;
+        public bool isTapped;
+        public Dictionary<string, int> counters = new();
+
+        public string PTString =>
+            (!string.IsNullOrEmpty(power) && !string.IsNullOrEmpty(toughness))
+                ? $"{power}/{toughness}" : "";
+    }
+}

unity-client/Assets/Scripts/Services/ApiClient.cs

@@ -283,5 +283,15 @@ namespace CommanderAILab.Services
             }
             onSuccess?.Invoke(request.downloadHandler.text);
         }
+
+        // -- Game (Live Battleground) ---------------------------------------
+
+        /// <summary>POST /api/game/action — submit a human player action during a live game.</summary>
+        public Coroutine PostGameAction(string json, Action<string> onSuccess, Action<string> onError = null)
+            => PostRaw("/api/game/action", json, onSuccess, onError);
+
+        /// <summary>POST /api/game/start — start a new live game with the given lobby config.</summary>
+        public Coroutine PostGameStart(string json, Action<string> onSuccess, Action<string> onError = null)
+            => PostRaw("/api/game/start", json, onSuccess, onError);
     }
 }

unity-client/Assets/Scripts/Services/GameWebSocketClient.cs

@@ -0,0 +1,207 @@
+using System;
+using System.Collections;
+using System.Collections.Concurrent;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using UnityEngine;
+using Newtonsoft.Json;
+using CommanderAILab.UI;
+
+namespace CommanderAILab.Services
+{
+    /// <summary>
+    /// WebSocket client for the live game backend.
+    /// Connects to ws://{serverHost}/ws/game/{gameId}.
+    ///
+    /// game_id is written to PlayerPrefs["GameId"] by LobbySetupModal
+    /// after a successful POST /api/game/start response.
+    ///
+    /// ServerUrl PlayerPref should be the HTTP base URL, e.g.
+    /// "http://localhost:8080" — this client converts it to ws://.
+    /// </summary>
+    public class GameWebSocketClient : MonoBehaviour
+    {
+        [SerializeField] private string defaultServerUrl   = "http://localhost:8080";
+        [SerializeField] private float  reconnectDelay     = 3f;
+        [SerializeField] private float  pingIntervalSec    = 15f;
+
+        private System.Net.WebSockets.ClientWebSocket _ws;
+        private CancellationTokenSource _cts;
+        private readonly ConcurrentQueue<(string type, string payload)> _mainThreadQueue = new();
+        private bool _running;
+        private float _pingTimer;
+        private string _wsUrl;
+
+        // ── Lifecycle ────────────────────────────────────────────────────────
+        private void Start()
+        {
+            _wsUrl = BuildWsUrl();
+            if (string.IsNullOrEmpty(_wsUrl))
+            {
+                Debug.LogError("[GameWebSocketClient] Could not build WS URL — PlayerPrefs 'GameId' is missing. " +
+                               "LobbySetupModal must set it after /api/game/start.");
+                return;
+            }
+
+            _running = true;
+            StartCoroutine(ConnectLoop());
+        }
+
+        private void Update()
+        {
+            // Drain main-thread queue
+            while (_mainThreadQueue.TryDequeue(out var msg))
+                GameStateManager.Instance?.ApplyServerEvent(msg.type, msg.payload);
+
+            // Ping
+            _pingTimer += Time.deltaTime;
+            if (_pingTimer >= pingIntervalSec)
+            {
+                _pingTimer = 0f;
+                _ = SendRawAsync("{\"type\":\"ping\"}");
+            }
+        }
+
+        private void OnDestroy()
+        {
+            _running = false;
+            _cts?.Cancel();
+            _ws?.Dispose();
+        }
+
+        // ── URL construction ────────────────────────────────────────────────
+        /// <summary>
+        /// Builds ws://{host}/ws/game/{gameId} from PlayerPrefs.
+        /// ServerUrl pref stores the HTTP base URL (e.g. http://localhost:8080).
+        /// GameId pref stores the game_id returned by /api/game/start.
+        /// </summary>
+        private string BuildWsUrl()
+        {
+            string gameId = PlayerPrefs.GetString("GameId", "");
+            if (string.IsNullOrEmpty(gameId))
+                return string.Empty;
+
+            string httpBase = PlayerPrefs.GetString("ServerUrl", defaultServerUrl).TrimEnd('/');
+
+            // Convert http(s):// to ws(s)://
+            string wsBase = httpBase
+                .Replace("https://", "wss://")
+                .Replace("http://",  "ws://");
+
+            return $"{wsBase}/ws/game/{gameId}";
+        }
+
+        // ── Connection loop ──────────────────────────────────────────────────
+        private IEnumerator ConnectLoop()
+        {
+            while (_running)
+            {
+                _cts = new CancellationTokenSource();
+                _ws  = new System.Net.WebSockets.ClientWebSocket();
+
+                bool connected = false;
+                var connectTask = _ws.ConnectAsync(new Uri(_wsUrl), _cts.Token);
+
+                yield return new WaitUntil(() => connectTask.IsCompleted);
+
+                if (!connectTask.IsFaulted && !connectTask.IsCanceled)
+                {
+                    connected = true;
+                    Debug.Log("[GameWebSocketClient] Connected to " + _wsUrl);
+                    _ = ReceiveLoop();
+                }
+                else
+                {
+                    Debug.LogWarning($"[GameWebSocketClient] Connect failed ({_wsUrl}): {connectTask.Exception?.Message}");
+                }
+
+                if (!connected)
+                {
+                    yield return new WaitForSeconds(reconnectDelay);
+                }
+                else
+                {
+                    yield return new WaitUntil(() =>
+                        _ws.State != System.Net.WebSockets.WebSocketState.Open);
+
+                    Debug.Log("[GameWebSocketClient] Disconnected — reconnecting...");
+                    yield return new WaitForSeconds(reconnectDelay);
+                }
+            }
+        }
+
+        // ── Receive loop (background thread) ────────────────────────────────
+        private async Task ReceiveLoop()
+        {
+            var buffer = new byte[8192];
+            try
+            {
+                while (_ws.State == System.Net.WebSockets.WebSocketState.Open)
+                {
+                    var sb = new StringBuilder();
+                    System.Net.WebSockets.WebSocketReceiveResult result;
+                    do
+                    {
+                        result = await _ws.ReceiveAsync(
+                            new ArraySegment<byte>(buffer), _cts.Token);
+                        sb.Append(Encoding.UTF8.GetString(buffer, 0, result.Count));
+                    } while (!result.EndOfMessage);
+
+                    if (result.MessageType ==
+                        System.Net.WebSockets.WebSocketMessageType.Close)
+                        break;
+
+                    ParseAndEnqueue(sb.ToString());
+                }
+            }
+            catch (OperationCanceledException) { }
+            catch (Exception ex)
+            {
+                Debug.LogWarning($"[GameWebSocketClient] ReceiveLoop error: {ex.Message}");
+            }
+        }
+
+        // ── Parse incoming JSON envelope ─────────────────────────────────────
+        private void ParseAndEnqueue(string raw)
+        {
+            try
+            {
+                var env = JsonConvert.DeserializeObject<WsEnvelope>(raw);
+                if (env == null) return;
+                if (env.type == "pong") return;
+                _mainThreadQueue.Enqueue((env.type, env.payload ?? raw));
+            }
+            catch
+            {
+                Debug.LogWarning($"[GameWebSocketClient] Failed to parse: {raw}");
+            }
+        }
+
+        // ── Send (public for external callers) ───────────────────────────────
+        public async Task SendRawAsync(string json)
+        {
+            if (_ws == null ||
+                _ws.State != System.Net.WebSockets.WebSocketState.Open) return;
+            try
+            {
+                var bytes = Encoding.UTF8.GetBytes(json);
+                await _ws.SendAsync(new ArraySegment<byte>(bytes),
+                    System.Net.WebSockets.WebSocketMessageType.Text,
+                    true, _cts?.Token ?? CancellationToken.None);
+            }
+            catch (Exception ex)
+            {
+                Debug.LogWarning($"[GameWebSocketClient] Send error: {ex.Message}");
+            }
+        }
+
+        // ── POCO ────────────────────────────────────────────────────────────────
+        [Serializable]
+        private class WsEnvelope
+        {
+            [JsonProperty("type")]    public string type;
+            [JsonProperty("payload")] public string payload;
+        }
+    }
+}

unity-client/Assets/Scripts/Services/ImageCache.cs

@@ -1,19 +1,22 @@
+using System;
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.Networking;
+using UnityEngine.UI;
 
 namespace CommanderAILab.Services
 {
     /// <summary>
     /// Singleton texture cache for card images.
-    /// Downloads and caches Scryfall card art as Sprite objects.
+    /// Downloads and caches Scryfall card art as Sprite or Texture2D.
     /// </summary>
     public class ImageCache : MonoBehaviour
     {
         public static ImageCache Instance { get; private set; }
 
-        private readonly Dictionary<string, Sprite> cache = new();
+        private readonly Dictionary<string, Sprite>    _spriteCache  = new();
+        private readonly Dictionary<string, Texture2D> _textureCache = new();
         [SerializeField] private int maxCacheSize = 500;
 
         private void Awake()
@@ -23,33 +26,67 @@ namespace CommanderAILab.Services
             DontDestroyOnLoad(gameObject);
         }
 
-        public void GetSprite(string url, System.Action<Sprite> callback)
+        // ── Sprite (existing usage) ───────────────────────────────────────────
+        public void GetSprite(string url, Action<Sprite> callback)
         {
             if (string.IsNullOrEmpty(url)) { callback?.Invoke(null); return; }
-            if (cache.TryGetValue(url, out var cached)) { callback?.Invoke(cached); return; }
+            if (_spriteCache.TryGetValue(url, out var cached)) { callback?.Invoke(cached); return; }
-            StartCoroutine(DownloadImage(url, callback));
+            StartCoroutine(DownloadSprite(url, callback));
         }
 
-        private IEnumerator DownloadImage(string url, System.Action<Sprite> callback)
+        private IEnumerator DownloadSprite(string url, Action<Sprite> callback)
         {
-            using var request = UnityWebRequestTexture.GetTexture(url);
+            using var req = UnityWebRequestTexture.GetTexture(url);
-            yield return request.SendWebRequest();
+            yield return req.SendWebRequest();
-
+            if (req.result != UnityWebRequest.Result.Success)
-            if (request.result != UnityWebRequest.Result.Success)
             {
-                Debug.LogWarning($"[ImageCache] Failed to load {url}: {request.error}");
+                Debug.LogWarning($"[ImageCache] Sprite failed {url}: {req.error}");
                 callback?.Invoke(null);
                 yield break;
             }
-
+            var tex    = DownloadHandlerTexture.GetContent(req);
-            var tex = DownloadHandlerTexture.GetContent(request);
             var sprite = Sprite.Create(tex, new Rect(0, 0, tex.width, tex.height), Vector2.one * 0.5f);
-
+            if (_spriteCache.Count >= maxCacheSize) _spriteCache.Clear();
-            if (cache.Count >= maxCacheSize) cache.Clear();
+            _spriteCache[url] = sprite;
-            cache[url] = sprite;
             callback?.Invoke(sprite);
         }
 
-        public void ClearCache() => cache.Clear();
+        // ── RawImage / Texture2D (battleground CardView + CommanderZoneWidget) ───
+        /// <summary>Load a card image URL directly into a RawImage component.</summary>
+        public IEnumerator LoadCard(string url, RawImage target)
+        {
+            if (target == null || string.IsNullOrEmpty(url)) yield break;
+            if (_textureCache.TryGetValue(url, out var cached)) { target.texture = cached; yield break; }
+            yield return DownloadTexture(url, tex => { if (target != null) target.texture = tex; });
+        }
+
+        /// <summary>
+        /// Load Scryfall art_crop into a RawImage by card name.
+        /// URL: https://api.scryfall.com/cards/named?exact={name}&format=image&version=art_crop
+        /// </summary>
+        public IEnumerator LoadArtCrop(string cardName, RawImage target)
+        {
+            if (target == null || string.IsNullOrEmpty(cardName)) yield break;
+            string url = $"https://api.scryfall.com/cards/named?exact={Uri.EscapeDataString(cardName)}&format=image&version=art_crop";
+            yield return LoadCard(url, target);
+        }
+
+        private IEnumerator DownloadTexture(string url, Action<Texture2D> callback)
+        {
+            using var req = UnityWebRequestTexture.GetTexture(url);
+            yield return req.SendWebRequest();
+            if (req.result != UnityWebRequest.Result.Success)
+            {
+                Debug.LogWarning($"[ImageCache] Texture failed {url}: {req.error}");
+                callback?.Invoke(null);
+                yield break;
+            }
+            var tex = DownloadHandlerTexture.GetContent(req);
+            if (_textureCache.Count >= maxCacheSize) _textureCache.Clear();
+            _textureCache[url] = tex;
+            callback?.Invoke(tex);
+        }
+
+        public void ClearCache() { _spriteCache.Clear(); _textureCache.Clear(); }
     }
 }

unity-client/Assets/Scripts/UI/Battleground/BattlegroundController.cs

@@ -0,0 +1,91 @@
+using System;
+using UnityEngine;
+using UnityEngine.UI;
+using UnityEngine.SceneManagement;
+using TMPro;
+using Newtonsoft.Json;
+using CommanderAILab.Models;
+using CommanderAILab.Services;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Master orchestrator for the Battleground scene.
+    /// Reads the lobby config written by SimulationController (PlayerPrefs "BattleSeats"),
+    /// wires up all seat panels, and opens the LobbySetupModal on start.
+    /// </summary>
+    public class BattlegroundController : MonoBehaviour
+    {
+        // ── Inspector ─────────────────────────────────────────────
+        [Header("Seat Panels")]
+        [SerializeField] private RectTransform[] seatPanels;   // [0]=bottom,[1]=right,[2]=top,[3]=left
+
+        [Header("Center")]
+        [SerializeField] private PhaseTrackerWidget phaseTracker;
+        [SerializeField] private TurnOrderBar       turnOrderBar;
+
+        [Header("Modals")]
+        [SerializeField] private LobbySetupModal    lobbyModal;
+
+        [Header("Navigation")]
+        [SerializeField] private Button             mainMenuButton;
+
+        // ── Seat rotations ────────────────────────────────────────
+        private static readonly float[] SeatRotations = { 0f, -90f, 180f, 90f };
+
+        // ── Lifecycle ──────────────────────────────────────────
+        private void Start()
+        {
+            ApplySeatRotations();
+            SubscribeEvents();
+
+            mainMenuButton.onClick.AddListener(() => SceneManager.LoadScene("MainMenu"));
+
+            // Pre-populate lobby from PlayerPrefs if arriving via SimulationController
+            string savedSeats = PlayerPrefs.GetString("BattleSeats", "");
+            if (lobbyModal != null)
+                lobbyModal.Open(savedSeats);
+        }
+
+        private void OnDestroy() => UnsubscribeEvents();
+
+        // ── Layout ─────────────────────────────────────────────
+        private void ApplySeatRotations()
+        {
+            for (int i = 0; i < seatPanels.Length; i++)
+            {
+                if (seatPanels[i] == null) continue;
+                seatPanels[i].localEulerAngles = new Vector3(0f, 0f, SeatRotations[i]);
+            }
+        }
+
+        // ── Event subscriptions ──────────────────────────────────
+        private void SubscribeEvents()
+        {
+            if (GameStateManager.Instance == null) return;
+            GameStateManager.Instance.OnTurnChanged  += OnTurnChanged;
+            GameStateManager.Instance.OnPhaseChanged += OnPhaseChanged;
+            GameStateManager.Instance.OnFullStateSync += OnFullStateSync;
+        }
+
+        private void UnsubscribeEvents()
+        {
+            if (GameStateManager.Instance == null) return;
+            GameStateManager.Instance.OnTurnChanged  -= OnTurnChanged;
+            GameStateManager.Instance.OnPhaseChanged -= OnPhaseChanged;
+            GameStateManager.Instance.OnFullStateSync -= OnFullStateSync;
+        }
+
+        private void OnTurnChanged(int seat) =>
+            turnOrderBar?.SetActiveSeat(seat);
+
+        private void OnPhaseChanged(PhaseTrackerWidget.Phase phase, int seat, int turn) =>
+            phaseTracker?.SetPhase(phase, seat, turn);
+
+        private void OnFullStateSync(GameState state)
+        {
+            // Delegate per-seat refresh to each SeatPanelController once those exist
+            turnOrderBar?.SetActiveSeat(state.activeSeat);
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/CardView.cs

@@ -0,0 +1,96 @@
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+using CommanderAILab.Models;
+using CommanderAILab.Services;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Visual representation of a single card in a CardZone.
+    /// Handles art loading via ImageCache, tapped rotation, and face-down state.
+    /// </summary>
+    public class CardView : MonoBehaviour
+    {
+        [Header("References")]
+        [SerializeField] private RawImage   artImage;
+        [SerializeField] private TMP_Text   nameLabel;
+        [SerializeField] private TMP_Text   ptLabel;           // power/toughness
+        [SerializeField] private TMP_Text   manaCostLabel;
+        [SerializeField] private GameObject tappedIndicator;   // e.g. coloured strip
+        [SerializeField] private GameObject summonSickOverlay; // semi-transparent overlay
+        [SerializeField] private GameObject faceDownOverlay;   // card back image object
+
+        public CardModel Model { get; private set; }
+        private bool _faceDown;
+
+        // ── Binding ─────────────────────────────────────────────
+        public void Bind(CardModel model, bool faceDown = false)
+        {
+            Model = model;
+            _faceDown = faceDown;
+            RefreshDisplay();
+        }
+
+        public void SetFaceDown(bool faceDown)
+        {
+            _faceDown = faceDown;
+            RefreshDisplay();
+        }
+
+        // ── State ──────────────────────────────────────────────
+        public void SetTapped(bool tapped)
+        {
+            if (Model == null) return;
+            Model.isTapped = tapped;
+            // Rotate the RectTransform -90 degrees when tapped
+            transform.localEulerAngles = tapped ? new Vector3(0f, 0f, -90f) : Vector3.zero;
+            if (tappedIndicator) tappedIndicator.SetActive(tapped);
+        }
+
+        public void SetSummonSick(bool sick)
+        {
+            if (Model == null) return;
+            Model.isSummoningSick = sick;
+            if (summonSickOverlay) summonSickOverlay.SetActive(sick);
+        }
+
+        // ── Internal ───────────────────────────────────────────
+        private void RefreshDisplay()
+        {
+            if (faceDownOverlay) faceDownOverlay.SetActive(_faceDown);
+            if (artImage)        artImage.gameObject.SetActive(!_faceDown);
+
+            if (nameLabel)
+                nameLabel.text = _faceDown ? "?" : (Model?.name ?? "");
+
+            bool hasStats = !_faceDown
+                            && Model != null
+                            && !string.IsNullOrEmpty(Model.power)
+                            && !string.IsNullOrEmpty(Model.toughness);
+
+            if (ptLabel)
+            {
+                ptLabel.text = hasStats ? $"{Model.power}/{Model.toughness}" : "";
+                ptLabel.gameObject.SetActive(hasStats);
+            }
+
+            if (manaCostLabel)
+            {
+                manaCostLabel.text = (!_faceDown && Model != null) ? Model.manaCost ?? "" : "";
+            }
+
+            // Load art via ImageCache if visible and URL available
+            if (!_faceDown && Model != null && !string.IsNullOrEmpty(Model.imageUri)
+                && artImage != null && ImageCache.Instance != null)
+            {
+                StartCoroutine(ImageCache.Instance.LoadCard(Model.imageUri, artImage));
+            }
+
+            // Reset tapped/sick overlays on rebind
+            if (tappedIndicator)   tappedIndicator.SetActive(false);
+            if (summonSickOverlay) summonSickOverlay.SetActive(false);
+            transform.localEulerAngles = Vector3.zero;
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/CardZone.cs

@@ -0,0 +1,65 @@
+using System.Collections.Generic;
+using UnityEngine;
+using CommanderAILab.Models;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Manages a collection of CardView instances inside one battlefield zone
+    /// (Hand, Battlefield, Graveyard, Exile, etc.).
+    /// The cardContainer should have a HorizontalLayoutGroup or GridLayoutGroup.
+    /// </summary>
+    public class CardZone : MonoBehaviour
+    {
+        [SerializeField] private BattleZone  zoneType;
+        [SerializeField] private GameObject  cardPrefab;     // CardPrefab.prefab
+        [SerializeField] private Transform   cardContainer;  // layout group parent
+        [SerializeField] private bool        faceDown;       // true for AI hand zones
+
+        private readonly List<CardView> _cards = new();
+
+        public BattleZone ZoneType => zoneType;
+        public IReadOnlyList<CardView> Cards => _cards;
+        public int Count => _cards.Count;
+
+        // ── Public API ─────────────────────────────────────────
+        public CardView AddCard(CardModel model)
+        {
+            var go   = Instantiate(cardPrefab, cardContainer);
+            var view = go.GetComponent<CardView>();
+            if (view == null)
+            {
+                Debug.LogError("[CardZone] CardPrefab missing CardView component.");
+                Destroy(go);
+                return null;
+            }
+            model.currentZone = zoneType;
+            view.Bind(model, faceDown);
+            _cards.Add(view);
+            return view;
+        }
+
+        public void RemoveCard(string cardId)
+        {
+            var view = _cards.Find(c => c.Model?.id == cardId);
+            if (view == null) return;
+            _cards.Remove(view);
+            Destroy(view.gameObject);
+        }
+
+        public void ClearAll()
+        {
+            foreach (var v in _cards) if (v != null) Destroy(v.gameObject);
+            _cards.Clear();
+        }
+
+        public void SetFaceDown(bool fd)
+        {
+            faceDown = fd;
+            foreach (var v in _cards) v?.SetFaceDown(fd);
+        }
+
+        public CardView FindById(string cardId) =>
+            _cards.Find(c => c.Model?.id == cardId);
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/CommanderDamageRow.cs

@@ -0,0 +1,69 @@
+using UnityEngine;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Displays cumulative commander damage received from each opposing seat.
+    /// Triggers elimination when any source reaches 21.
+    /// Attach one to each seat panel; set SeatIndex in inspector.
+    /// </summary>
+    public class CommanderDamageRow : MonoBehaviour
+    {
+        /// <summary>The seat this row belongs to (receives damage).</summary>
+        [SerializeField] private int seatIndex;
+
+        /// <summary>
+        /// Labels for damage received from each seat.
+        /// fromSeatLabels[i] corresponds to global seat i.
+        /// The label for this seat's own index will be hidden (can't deal commander damage to yourself).
+        /// </summary>
+        [SerializeField] private TMP_Text[] fromSeatLabels; // length 4
+
+        private readonly int[] _damage = new int[4];
+
+        private void Start()
+        {
+            // Hide this seat's own label
+            if (fromSeatLabels != null && seatIndex < fromSeatLabels.Length
+                && fromSeatLabels[seatIndex] != null)
+                fromSeatLabels[seatIndex].gameObject.SetActive(false);
+
+            RefreshAllLabels();
+        }
+
+        public void AddDamage(int fromSeat, int amount)
+        {
+            if (fromSeat < 0 || fromSeat >= 4 || fromSeat == seatIndex) return;
+            _damage[fromSeat] = Mathf.Max(0, _damage[fromSeat] + amount);
+            RefreshLabel(fromSeat);
+
+            if (_damage[fromSeat] >= 21)
+                GameStateManager.Instance?.EliminatePlayer(seatIndex, "commander_damage");
+        }
+
+        public void SetDamage(int fromSeat, int value)
+        {
+            if (fromSeat < 0 || fromSeat >= 4 || fromSeat == seatIndex) return;
+            _damage[fromSeat] = Mathf.Max(0, value);
+            RefreshLabel(fromSeat);
+        }
+
+        public int GetDamage(int fromSeat) =>
+            (fromSeat >= 0 && fromSeat < 4) ? _damage[fromSeat] : 0;
+
+        private void RefreshLabel(int fromSeat)
+        {
+            if (fromSeatLabels == null || fromSeat >= fromSeatLabels.Length) return;
+            var lbl = fromSeatLabels[fromSeat];
+            if (lbl == null) return;
+            lbl.text = _damage[fromSeat] > 0 ? _damage[fromSeat].ToString() : "0";
+            lbl.color = _damage[fromSeat] >= 21 ? Color.red : Color.white;
+        }
+
+        private void RefreshAllLabels()
+        {
+            for (int i = 0; i < 4; i++) RefreshLabel(i);
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/CommanderZoneWidget.cs

@@ -0,0 +1,69 @@
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+using CommanderAILab.Models;
+using CommanderAILab.Services;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Per-seat commander zone widget.
+    /// Shows: art crop banner, commander name, cast count, commander tax.
+    /// Requires ImageCache singleton in scene.
+    /// </summary>
+    public class CommanderZoneWidget : MonoBehaviour
+    {
+        [Header("References")]
+        [SerializeField] private RawImage   artCropImage;
+        [SerializeField] private TMP_Text   commanderNameLabel;
+        [SerializeField] private TMP_Text   castCountLabel;
+        [SerializeField] private TMP_Text   taxLabel;
+        [SerializeField] private UnityEngine.UI.Button castCommanderBtn;
+
+        public CardModel CommanderCard { get; private set; }
+        private int _castCount = 0;
+
+        // ── Binding ───────────────────────────────────────────
+        public void Bind(CardModel commander)
+        {
+            CommanderCard = commander;
+            _castCount    = commander != null ? commander.counters.GetValueOrDefault("cast_count", 0) : 0;
+
+            if (commanderNameLabel)
+                commanderNameLabel.text = commander?.name ?? "No Commander";
+
+            UpdateTaxDisplay();
+
+            // Load art crop from Scryfall
+            if (commander != null && !string.IsNullOrEmpty(commander.name)
+                && artCropImage != null && ImageCache.Instance != null)
+            {
+                StartCoroutine(ImageCache.Instance.LoadArtCrop(commander.name, artCropImage));
+            }
+        }
+
+        // ── Cast tracking ──────────────────────────────────────
+        public void OnCommanderCast()
+        {
+            _castCount++;
+            UpdateTaxDisplay();
+        }
+
+        public void SetCastCount(int count)
+        {
+            _castCount = Mathf.Max(0, count);
+            UpdateTaxDisplay();
+        }
+
+        // ── Internal ──────────────────────────────────────────
+        private void UpdateTaxDisplay()
+        {
+            if (castCountLabel)
+                castCountLabel.text = _castCount == 0 ? "Not yet cast" : $"Cast #{_castCount}";
+
+            int tax = _castCount * 2;
+            if (taxLabel)
+                taxLabel.text = tax == 0 ? "No tax" : $"+{tax} ☀ tax";
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/EliminationHandler.cs

@@ -0,0 +1,116 @@
+using System.Collections;
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Handles the visual elimination sequence for a seat panel.
+    /// On elimination: plays a flash animation, applies a grayscale material, and
+    /// shows an elimination banner with cause of death text.
+    /// Requires a URP ShaderGraph material "EliminatedGrayscale" in Resources/.
+    /// </summary>
+    public class EliminationHandler : MonoBehaviour
+    {
+        [Header("References")]
+        [SerializeField] private int         seatIndex;
+        [SerializeField] private CanvasGroup seatCanvasGroup;    // seat panel root CanvasGroup
+        [SerializeField] private Image       eliminationOverlay; // full-panel semi-transparent overlay
+        [SerializeField] private TMP_Text    eliminationLabel;   // "ELIMINATED" text
+        [SerializeField] private TMP_Text    causeLabel;         // cause of death
+        [SerializeField] private Image[]     grayscaleTargets;   // RawImages to recolor to grayscale
+
+        private static readonly Color GrayscaleTint = new Color(0.4f, 0.4f, 0.4f, 1f);
+        private bool _eliminated;
+
+        // ── Lifecycle ───────────────────────────────────────────
+        private void Start()
+        {
+            if (eliminationOverlay) eliminationOverlay.gameObject.SetActive(false);
+            if (eliminationLabel)   eliminationLabel.gameObject.SetActive(false);
+            if (causeLabel)         causeLabel.gameObject.SetActive(false);
+
+            if (GameStateManager.Instance != null)
+                GameStateManager.Instance.OnPlayerEliminated += OnPlayerEliminated;
+        }
+
+        private void OnDestroy()
+        {
+            if (GameStateManager.Instance != null)
+                GameStateManager.Instance.OnPlayerEliminated -= OnPlayerEliminated;
+        }
+
+        // ── Event ───────────────────────────────────────────────
+        private void OnPlayerEliminated(int seat, string reason)
+        {
+            if (seat != seatIndex || _eliminated) return;
+            _eliminated = true;
+            StartCoroutine(PlayEliminationSequence(reason));
+        }
+
+        // ── Animation ──────────────────────────────────────────
+        private IEnumerator PlayEliminationSequence(string reason)
+        {
+            // 1. Red flash
+            if (eliminationOverlay)
+            {
+                eliminationOverlay.gameObject.SetActive(true);
+                eliminationOverlay.color = new Color(1f, 0f, 0f, 0f);
+                yield return FadeImage(eliminationOverlay, 0f, 0.6f, 0.15f);
+                yield return FadeImage(eliminationOverlay, 0.6f, 0f, 0.4f);
+                eliminationOverlay.color = new Color(0f, 0f, 0f, 0.4f);  // keep dark overlay
+            }
+
+            // 2. Grayscale tint on card art panels
+            foreach (var img in grayscaleTargets)
+                if (img != null) img.color = GrayscaleTint;
+
+            // 3. Fade-down CanvasGroup to 60%
+            if (seatCanvasGroup)
+            {
+                seatCanvasGroup.interactable = false;
+                seatCanvasGroup.blocksRaycasts = false;
+                yield return FadeCanvasGroup(seatCanvasGroup, seatCanvasGroup.alpha, 0.6f, 0.3f);
+            }
+
+            // 4. Show banner
+            if (eliminationLabel) eliminationLabel.gameObject.SetActive(true);
+            if (causeLabel)
+            {
+                causeLabel.text = reason switch
+                {
+                    "life"              => "Life total reached 0",
+                    "commander_damage"  => "Commander damage (21+)",
+                    "poison"            => "Poison counters (10+)",
+                    "deck_empty"        => "Failed to draw",
+                    _                   => reason
+                };
+                causeLabel.gameObject.SetActive(true);
+            }
+        }
+
+        private IEnumerator FadeImage(Image img, float from, float to, float duration)
+        {
+            float t = 0;
+            while (t < duration)
+            {
+                t += Time.deltaTime;
+                var c = img.color;
+                c.a = Mathf.Lerp(from, to, t / duration);
+                img.color = c;
+                yield return null;
+            }
+            var final = img.color;
+            final.a = to;
+            img.color = final;
+        }
+
+        private IEnumerator FadeCanvasGroup(CanvasGroup cg, float from, float to, float duration)
+        {
+            float t = 0;
+            while (t < duration) { t += Time.deltaTime; cg.alpha = Mathf.Lerp(from, to, t / duration); yield return null; }
+            cg.alpha = to;
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/GameStateManager.cs

@@ -0,0 +1,119 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+using Newtonsoft.Json;
+using CommanderAILab.Models;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Singleton event hub for the live battleground game state.
+    /// All UI widgets subscribe to these events instead of polling.
+    /// Receives parsed server events from GameWebSocketClient.
+    /// </summary>
+    public class GameStateManager : MonoBehaviour
+    {
+        public static GameStateManager Instance { get; private set; }
+
+        // ── Events ────────────────────────────────────────────────
+        public event Action<int>                              OnTurnChanged;      // activeSeat
+        public event Action<PhaseTrackerWidget.Phase, int, int> OnPhaseChanged;   // phase, seat, turnNumber
+        public event Action<int>                              OnPriorityChanged;  // seatIndex
+        public event Action<int, int>                         OnLifeChanged;      // seatIndex, newLife
+        public event Action<int, string>                      OnPlayerEliminated; // seatIndex, reason
+        public event Action<List<StackZoneController.StackItem>> OnStackUpdated;
+        public event Action<GameState>                        OnFullStateSync;
+
+        // ── State ────────────────────────────────────────────────
+        public int TurnNumber { get; private set; } = 1;
+        private GameState _state;
+
+        // ── Lifecycle ─────────────────────────────────────────────
+        private void Awake()
+        {
+            if (Instance != null && Instance != this) { Destroy(gameObject); return; }
+            Instance = this;
+        }
+
+        // ── Server event dispatch ───────────────────────────────────
+        /// <summary>Called by GameWebSocketClient on the Unity main thread.</summary>
+        public void ApplyServerEvent(string type, string payload)
+        {
+            try
+            {
+                switch (type)
+                {
+                    case "state_update":
+                        _state = JsonConvert.DeserializeObject<GameState>(payload);
+                        if (_state != null) OnFullStateSync?.Invoke(_state);
+                        break;
+
+                    case "turn_start":
+                        var ts = JsonConvert.DeserializeObject<TurnStartEvent>(payload);
+                        if (ts != null) { TurnNumber = ts.turnNumber; OnTurnChanged?.Invoke(ts.seat); }
+                        break;
+
+                    case "phase_change":
+                        var pc = JsonConvert.DeserializeObject<PhaseChangeEvent>(payload);
+                        if (pc != null)
+                            OnPhaseChanged?.Invoke((PhaseTrackerWidget.Phase)pc.phaseIndex, pc.seat, TurnNumber);
+                        break;
+
+                    case "priority":
+                        var pv = JsonConvert.DeserializeObject<PriorityEvent>(payload);
+                        if (pv != null) OnPriorityChanged?.Invoke(pv.seat);
+                        break;
+
+                    case "life_change":
+                        var lc = JsonConvert.DeserializeObject<LifeChangeEvent>(payload);
+                        if (lc != null) OnLifeChanged?.Invoke(lc.seat, lc.newLife);
+                        break;
+
+                    case "stack_update":
+                        var su = JsonConvert.DeserializeObject<StackUpdateEvent>(payload);
+                        if (su?.items != null) OnStackUpdated?.Invoke(su.items);
+                        break;
+
+                    case "player_elim":
+                        var pe = JsonConvert.DeserializeObject<EliminationEvent>(payload);
+                        if (pe != null) EliminatePlayer(pe.seat, pe.reason);
+                        break;
+
+                    default:
+                        Debug.LogWarning($"[GameStateManager] Unknown event type: {type}");
+                        break;
+                }
+            }
+            catch (Exception ex)
+            {
+                Debug.LogError($"[GameStateManager] ApplyServerEvent failed ({type}): {ex.Message}");
+            }
+        }
+
+        /// <summary>Trigger elimination (called by LifeTrackerWidget, CommanderDamageRow, or server event).</summary>
+        public void EliminatePlayer(int seatIndex, string reason) =>
+            OnPlayerEliminated?.Invoke(seatIndex, reason);
+
+        // ── Debug helpers (editor only) ─────────────────────────────
+#if UNITY_EDITOR
+        private void OnGUI()
+        {
+            GUILayout.BeginArea(new Rect(10, 10, 220, 200));
+            GUILayout.Label("[GSM Debug]");
+            if (GUILayout.Button("Fake Turn 1 Start"))  ApplyServerEvent("turn_start",  "{\"seat\":0,\"turnNumber\":1}");
+            if (GUILayout.Button("Advance Phase Main1")) ApplyServerEvent("phase_change","{\"phaseIndex\":3,\"seat\":0}");
+            if (GUILayout.Button("Priority Seat 0"))    ApplyServerEvent("priority",    "{\"seat\":0}");
+            if (GUILayout.Button("Elim Seat 2"))        EliminatePlayer(2, "life");
+            GUILayout.EndArea();
+        }
+#endif
+
+        // ── Private event POCOs ───────────────────────────────────
+        [Serializable] private class TurnStartEvent  { public int seat; public int turnNumber; }
+        [Serializable] private class PhaseChangeEvent { public int phaseIndex; public int seat; }
+        [Serializable] private class PriorityEvent   { public int seat; }
+        [Serializable] private class LifeChangeEvent { public int seat; public int newLife; }
+        [Serializable] private class StackUpdateEvent { public List<StackZoneController.StackItem> items; }
+        [Serializable] private class EliminationEvent { public int seat; public string reason; }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/HumanActionBar.cs

@@ -0,0 +1,101 @@
+using System;
+using System.Collections;
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+using Newtonsoft.Json;
+using CommanderAILab.Services;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Human player action bar — only active when seat 0 has priority.
+    /// Buttons post actions to /api/game/action.
+    /// Subscribes to GameStateManager.OnPriorityChanged.
+    /// </summary>
+    public class HumanActionBar : MonoBehaviour
+    {
+        [Header("References")]
+        [SerializeField] private ApiClient  apiClient;
+        [SerializeField] private GameObject actionBar;         // root panel
+        [SerializeField] private Button     passPriorityBtn;
+        [SerializeField] private Button     endTurnBtn;
+        [SerializeField] private Button     declareAttackersBtn;
+        [SerializeField] private Button     declareBlockersBtn;
+        [SerializeField] private TMP_Text   priorityLabel;
+        [SerializeField] private TMP_Text   feedbackLabel;
+
+        private bool _hasPriority;
+
+        // ── Lifecycle ───────────────────────────────────────────
+        private void Start()
+        {
+            passPriorityBtn   ?.onClick.AddListener(() => PostAction("pass_priority"));
+            endTurnBtn        ?.onClick.AddListener(() => PostAction("end_turn"));
+            declareAttackersBtn?.onClick.AddListener(() => PostAction("declare_attackers"));
+            declareBlockersBtn ?.onClick.AddListener(() => PostAction("declare_blockers"));
+
+            if (GameStateManager.Instance != null)
+            {
+                GameStateManager.Instance.OnPriorityChanged += OnPriorityChanged;
+                GameStateManager.Instance.OnPhaseChanged   += OnPhaseChanged;
+            }
+
+            SetPriority(false);
+        }
+
+        private void OnDestroy()
+        {
+            if (GameStateManager.Instance == null) return;
+            GameStateManager.Instance.OnPriorityChanged -= OnPriorityChanged;
+            GameStateManager.Instance.OnPhaseChanged   -= OnPhaseChanged;
+        }
+
+        // ── Priority visibility ──────────────────────────────────
+        private void OnPriorityChanged(int seatIndex)
+        {
+            SetPriority(seatIndex == 0);
+        }
+
+        private void OnPhaseChanged(PhaseTrackerWidget.Phase phase, int seat, int turn)
+        {
+            // Only show combat buttons during combat phases
+            bool inCombat = phase >= PhaseTrackerWidget.Phase.DeclareAttackers
+                         && phase <= PhaseTrackerWidget.Phase.EndCombat;
+            if (declareAttackersBtn) declareAttackersBtn.gameObject.SetActive(inCombat && _hasPriority);
+            if (declareBlockersBtn)  declareBlockersBtn.gameObject.SetActive(inCombat && _hasPriority);
+        }
+
+        private void SetPriority(bool hasPriority)
+        {
+            _hasPriority = hasPriority;
+            if (actionBar)     actionBar.SetActive(hasPriority);
+            if (priorityLabel) priorityLabel.text = hasPriority ? "Your Priority" : "";
+        }
+
+        // ── Action posting ─────────────────────────────────────
+        private void PostAction(string actionType)
+        {
+            var payload = JsonConvert.SerializeObject(new { action = actionType, seat = 0 });
+            apiClient?.PostGameAction(payload,
+                _ => ShowFeedback(actionType),
+                err => ShowFeedback($"Error: {err}", isError: true));
+        }
+
+        private void ShowFeedback(string msg, bool isError = false)
+        {
+            if (!feedbackLabel) return;
+            StopCoroutine(nameof(FadeOutFeedback));
+            feedbackLabel.text  = msg;
+            feedbackLabel.color = isError ? Color.red : Color.green;
+            feedbackLabel.gameObject.SetActive(true);
+            StartCoroutine(nameof(FadeOutFeedback));
+        }
+
+        private IEnumerator FadeOutFeedback()
+        {
+            yield return new WaitForSeconds(1.5f);
+            if (feedbackLabel) feedbackLabel.gameObject.SetActive(false);
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/LifeTrackerWidget.cs

@@ -0,0 +1,78 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Per-seat life total widget with +/- buttons, danger flash, and history log.
+    /// Calls GameStateManager.EliminatePlayer when life reaches 0.
+    /// </summary>
+    public class LifeTrackerWidget : MonoBehaviour
+    {
+        [Header("References")]
+        [SerializeField] private TMP_Text lifeLabel;
+        [SerializeField] private Button   plusOneBtn;
+        [SerializeField] private Button   minusOneBtn;
+        [SerializeField] private Button   plusFiveBtn;
+        [SerializeField] private Button   minusFiveBtn;
+        [SerializeField] private GameObject dangerFlash;   // red glow overlay, shown at <=5 life
+
+        [Header("Config")]
+        [SerializeField] private int startingLife = 40;
+        public int SeatIndex { get; set; }
+
+        private int _life;
+        private readonly List<LifeHistoryEntry> _history = new();
+
+        // ── Lifecycle ───────────────────────────────────────────
+        private void Start()
+        {
+            SetLife(startingLife);
+            plusOneBtn .onClick.AddListener(() => AdjustLife(+1, "manual"));
+            minusOneBtn.onClick.AddListener(() => AdjustLife(-1, "manual"));
+            plusFiveBtn .onClick.AddListener(() => AdjustLife(+5, "manual"));
+            minusFiveBtn.onClick.AddListener(() => AdjustLife(-5, "manual"));
+        }
+
+        // ── Public API ─────────────────────────────────────────
+        public int Life => _life;
+
+        public void AdjustLife(int delta, string source)
+        {
+            _life = Mathf.Max(0, _life + delta);
+            RefreshDisplay();
+
+            int turn = GameStateManager.Instance != null ? GameStateManager.Instance.TurnNumber : 0;
+            _history.Add(new LifeHistoryEntry { delta = delta, source = source, turn = turn });
+
+            if (_life == 0)
+                GameStateManager.Instance?.EliminatePlayer(SeatIndex, "life");
+        }
+
+        public void SetLife(int value)
+        {
+            _life = Mathf.Max(0, value);
+            RefreshDisplay();
+        }
+
+        public List<LifeHistoryEntry> GetHistory() => _history;
+
+        // ── Internal ───────────────────────────────────────────
+        private void RefreshDisplay()
+        {
+            if (lifeLabel)   lifeLabel.text = _life.ToString();
+            if (dangerFlash) dangerFlash.SetActive(_life <= 5 && _life > 0);
+        }
+
+        [Serializable]
+        public class LifeHistoryEntry
+        {
+            public int    delta;
+            public string source;
+            public int    turn;
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/LobbySetupModal.cs

@@ -0,0 +1,249 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.UI;
+using UnityEngine.SceneManagement;
+using TMPro;
+using Newtonsoft.Json;
+using CommanderAILab.Services;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Modal shown at Battleground scene start.
+    /// Configures 4 seats (Human vs AI, deck choice, AI style).
+    /// On Confirm:
+    ///   1. POSTs seat config to POST /api/game/start
+    ///   2. Saves game_id + ws_url to PlayerPrefs
+    ///   3. Loads Battleground scene
+    /// </summary>
+    public class LobbySetupModal : MonoBehaviour
+    {
+        [Header("Seat Rows (4)")]
+        [SerializeField] private LobbyRowUI[] seatRows;   // length 4
+
+        [Header("Buttons")]
+        [SerializeField] private Button confirmButton;
+        [SerializeField] private Button cancelButton;
+
+        [Header("Feedback")]
+        [SerializeField] private TMP_Text errorLabel;     // assign in Inspector; hidden by default
+
+        [SerializeField] private ApiClient apiClient;
+
+        private List<string> _deckNames = new();
+
+        // ── Open ────────────────────────────────────────────────
+        public void Open(string savedSeatsJson)
+        {
+            gameObject.SetActive(true);
+            SetError(null);
+
+            confirmButton.onClick.AddListener(OnConfirm);
+            cancelButton.onClick.AddListener(() => SceneManager.LoadScene("MainMenu"));
+
+            // Load deck list for dropdowns
+            apiClient?.GetDecks(
+                json =>
+                {
+                    try
+                    {
+                        var w = JsonConvert.DeserializeObject<DecksWrapper>(json);
+                        _deckNames = new List<string>();
+                        if (w?.decks != null)
+                            foreach (var d in w.decks) _deckNames.Add(d.name);
+                    }
+                    catch { _deckNames = new List<string>(); }
+                    PopulateRows(savedSeatsJson);
+                },
+                _ => PopulateRows(savedSeatsJson));
+        }
+
+        private void PopulateRows(string savedJson)
+        {
+            List<SeatConfig> saved = null;
+            try { saved = JsonConvert.DeserializeObject<List<SeatConfig>>(savedJson); } catch { }
+
+            for (int i = 0; i < seatRows.Length; i++)
+            {
+                if (seatRows[i] == null) continue;
+                var cfg = (saved != null && i < saved.Count) ? saved[i] : null;
+                seatRows[i].Populate(i, _deckNames, cfg);
+            }
+        }
+
+        // ── Confirm → POST /api/game/start ──────────────────────
+        private void OnConfirm()
+        {
+            SetError(null);
+            confirmButton.interactable = false;
+
+            // Build local seat list
+            var configs = new List<SeatConfig>();
+            foreach (var row in seatRows)
+                configs.Add(row?.GetConfig() ?? new SeatConfig());
+
+            // Save locally so Battleground scene can read seat metadata
+            PlayerPrefs.SetString("BattleSeats", JsonConvert.SerializeObject(configs));
+            PlayerPrefs.Save();
+
+            // Build backend request — maps local SeatConfig → StartGameRequest
+            var apiSeats = new List<ApiSeatConfig>();
+            for (int i = 0; i < configs.Count; i++)
+            {
+                var c = configs[i];
+                apiSeats.Add(new ApiSeatConfig
+                {
+                    seat_index  = i,
+                    seat_type   = c.isHuman ? "Human" : $"AI {c.aiStyle}",
+                    deck_name   = c.deckName ?? "",
+                    player_name = c.isHuman ? "Player" : $"AI {i}",
+                });
+            }
+
+            var requestJson = JsonConvert.SerializeObject(new StartGameRequest { seats = apiSeats });
+
+            apiClient.PostGameStart(
+                requestJson,
+                onSuccess: responseJson =>
+                {
+                    try
+                    {
+                        var resp = JsonConvert.DeserializeObject<StartGameResponse>(responseJson);
+                        if (resp == null || string.IsNullOrEmpty(resp.game_id))
+                        {
+                            OnStartError("Server returned an invalid response.");
+                            return;
+                        }
+
+                        // Persist game_id and ws_url so GameWebSocketClient can connect
+                        PlayerPrefs.SetString("GameId",  resp.game_id);
+                        PlayerPrefs.SetString("WsUrl",   resp.ws_url ?? $"/ws/game/{resp.game_id}");
+                        PlayerPrefs.Save();
+
+                        gameObject.SetActive(false);
+                        SceneManager.LoadScene("Battleground");
+                    }
+                    catch (Exception ex)
+                    {
+                        OnStartError($"Parse error: {ex.Message}");
+                    }
+                },
+                onError: err => OnStartError($"Failed to start game: {err}"));
+        }
+
+        private void OnStartError(string message)
+        {
+            Debug.LogError("[LobbySetupModal] " + message);
+            SetError(message);
+            confirmButton.interactable = true;
+        }
+
+        private void SetError(string message)
+        {
+            if (errorLabel == null) return;
+            errorLabel.text    = message ?? string.Empty;
+            errorLabel.gameObject.SetActive(!string.IsNullOrEmpty(message));
+        }
+
+        // ── Models ─────────────────────────────────────────────
+
+        /// <summary>Local / PlayerPrefs representation of a seat.</summary>
+        [Serializable]
+        public class SeatConfig
+        {
+            public bool   isHuman;
+            public string deckName;
+            public string aiStyle;   // Aggro / Control / Combo / Political
+        }
+
+        /// <summary>Matches routes/game.py SeatConfig schema.</summary>
+        [Serializable]
+        private class ApiSeatConfig
+        {
+            public int    seat_index;
+            public string seat_type;
+            public string deck_name;
+            public string player_name;
+        }
+
+        /// <summary>Matches routes/game.py StartGameRequest schema.</summary>
+        [Serializable]
+        private class StartGameRequest
+        {
+            public List<ApiSeatConfig> seats;
+        }
+
+        /// <summary>Matches routes/game.py StartGameResponse schema.</summary>
+        [Serializable]
+        private class StartGameResponse
+        {
+            public string game_id;
+            public string status;
+            public string ws_url;
+        }
+
+        [Serializable] private class DecksWrapper { public List<DeckEntry> decks; }
+        [Serializable] private class DeckEntry { public string name; }
+    }
+
+    /// <summary>Per-seat row in the lobby modal (UI bindings are set in inspector).</summary>
+    [Serializable]
+    public class LobbyRowUI : MonoBehaviour
+    {
+        [SerializeField] private TMP_Text     seatLabel;
+        [SerializeField] private Toggle       humanToggle;
+        [SerializeField] private TMP_Dropdown deckDropdown;
+        [SerializeField] private TMP_Dropdown aiStyleDropdown;
+
+        private static readonly List<string> AiStyles = new() { "Aggro", "Control", "Combo", "Political" };
+
+        public void Populate(int seatIndex, List<string> deckNames, LobbySetupModal.SeatConfig saved)
+        {
+            if (seatLabel) seatLabel.text = seatIndex == 0 ? "Seat 0 (You)" : $"Seat {seatIndex} (AI)";
+
+            if (humanToggle)
+            {
+                humanToggle.isOn = saved?.isHuman ?? (seatIndex == 0);
+                humanToggle.onValueChanged.AddListener(isHuman =>
+                {
+                    if (aiStyleDropdown) aiStyleDropdown.gameObject.SetActive(!isHuman);
+                });
+                if (aiStyleDropdown) aiStyleDropdown.gameObject.SetActive(!humanToggle.isOn);
+            }
+
+            if (deckDropdown)
+            {
+                deckDropdown.ClearOptions();
+                var opts = new List<string> { "-- Select Deck --" };
+                opts.AddRange(deckNames);
+                deckDropdown.AddOptions(opts);
+                if (!string.IsNullOrEmpty(saved?.deckName))
+                {
+                    int idx = opts.IndexOf(saved.deckName);
+                    deckDropdown.value = idx >= 0 ? idx : 0;
+                }
+            }
+
+            if (aiStyleDropdown)
+            {
+                aiStyleDropdown.ClearOptions();
+                aiStyleDropdown.AddOptions(AiStyles);
+                if (!string.IsNullOrEmpty(saved?.aiStyle))
+                {
+                    int idx = AiStyles.IndexOf(saved.aiStyle);
+                    aiStyleDropdown.value = idx >= 0 ? idx : 0;
+                }
+            }
+        }
+
+        public LobbySetupModal.SeatConfig GetConfig() => new()
+        {
+            isHuman  = humanToggle?.isOn ?? false,
+            deckName = deckDropdown != null && deckDropdown.value > 0
+                       ? deckDropdown.options[deckDropdown.value].text : "",
+            aiStyle  = aiStyleDropdown != null
+                       ? aiStyleDropdown.options[aiStyleDropdown.value].text : "Aggro"
+        };
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/ManaPoolDisplay.cs

@@ -0,0 +1,70 @@
+using System.Collections.Generic;
+using UnityEngine;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Displays the mana pool for one seat as coloured symbol + count labels.
+    /// Symbols are hidden when the mana amount is 0.
+    /// Resets on each phase-change event from GameStateManager.
+    /// </summary>
+    public class ManaPoolDisplay : MonoBehaviour
+    {
+        [SerializeField] private int seatIndex;
+
+        [Header("Mana Labels (W U B R G C order)")]
+        [SerializeField] private TMP_Text[] manaLabels;      // length 6
+        [SerializeField] private GameObject[] manaSymbols;   // parent GO per mana type (contains Image)
+
+        private static readonly string[] ManaKeys = { "W", "U", "B", "R", "G", "C" };
+
+        // ── Lifecycle ───────────────────────────────────────────
+        private void Start()
+        {
+            if (GameStateManager.Instance != null)
+            {
+                GameStateManager.Instance.OnPhaseChanged  += OnPhaseChanged;
+                GameStateManager.Instance.OnFullStateSync += OnFullStateSync;
+            }
+            UpdatePool(null);
+        }
+
+        private void OnDestroy()
+        {
+            if (GameStateManager.Instance == null) return;
+            GameStateManager.Instance.OnPhaseChanged  -= OnPhaseChanged;
+            GameStateManager.Instance.OnFullStateSync -= OnFullStateSync;
+        }
+
+        // ── Public API ─────────────────────────────────────────
+        public void UpdatePool(Dictionary<string, int> pool)
+        {
+            for (int i = 0; i < ManaKeys.Length; i++)
+            {
+                int amt = 0;
+                pool?.TryGetValue(ManaKeys[i], out amt);
+
+                bool show = amt > 0;
+                if (i < manaLabels.Length  && manaLabels[i]  != null)
+                    manaLabels[i].text = show ? amt.ToString() : "";
+                if (i < manaSymbols.Length && manaSymbols[i] != null)
+                    manaSymbols[i].SetActive(show);
+            }
+        }
+
+        // ── Event handlers ─────────────────────────────────────
+        private void OnPhaseChanged(PhaseTrackerWidget.Phase phase, int seat, int turn)
+        {
+            // Mana pool empties at the end of each phase
+            if (phase == PhaseTrackerWidget.Phase.Cleanup)
+                UpdatePool(null);
+        }
+
+        private void OnFullStateSync(GameState state)
+        {
+            if (state?.seats == null || seatIndex >= state.seats.Count) return;
+            UpdatePool(state.seats[seatIndex].manaPool);
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/PhaseStepButton.cs

@@ -0,0 +1,31 @@
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// A single phase pill in the PhaseTrackerWidget strip.
+    /// Changes color, font weight, and scale when activated.
+    /// </summary>
+    public class PhaseStepButton : MonoBehaviour
+    {
+        [SerializeField] private Image      background;
+        [SerializeField] private TMP_Text   label;
+
+        [Header("Colors")]
+        [SerializeField] private Color activeColor   = new Color(1f, 0.85f, 0f);     // amber/yellow
+        [SerializeField] private Color inactiveColor = new Color(0.2f, 0.2f, 0.2f);  // dark grey
+
+        private Vector3 _baseScale;
+
+        private void Awake() => _baseScale = transform.localScale;
+
+        public void SetActive(bool active)
+        {
+            if (background) background.color = active ? activeColor : inactiveColor;
+            if (label)      label.fontStyle   = active ? TMPro.FontStyles.Bold : TMPro.FontStyles.Normal;
+            transform.localScale = active ? _baseScale * 1.1f : _baseScale;
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/PhaseTrackerWidget.cs

@@ -0,0 +1,80 @@
+using UnityEngine;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Horizontal strip of 13 phase/step buttons in the BattlefieldCenter panel.
+    /// Subscribes to GameStateManager.OnPhaseChanged.
+    /// Test without backend: press Space in Play Mode (debug binding below).
+    /// </summary>
+    public class PhaseTrackerWidget : MonoBehaviour
+    {
+        public enum Phase
+        {
+            Untap = 0,
+            Upkeep,
+            Draw,
+            Main1,
+            BeginCombat,
+            DeclareAttackers,
+            DeclareBlockers,
+            FirstStrikeDamage,
+            Damage,
+            EndCombat,
+            Main2,
+            EndStep,
+            Cleanup
+        }
+
+        [SerializeField] private PhaseStepButton[] stepButtons;    // 13 buttons, one per Phase
+        [SerializeField] private TMP_Text          activePlayerLabel;
+        [SerializeField] private TMP_Text          turnNumberLabel;
+
+        private Phase _currentPhase;
+
+        // ── Lifecycle ───────────────────────────────────────────
+        private void Start()
+        {
+            if (GameStateManager.Instance != null)
+                GameStateManager.Instance.OnPhaseChanged += SetPhase;
+
+            SetPhase(Phase.Untap, 0, 1);
+        }
+
+        private void OnDestroy()
+        {
+            if (GameStateManager.Instance != null)
+                GameStateManager.Instance.OnPhaseChanged -= SetPhase;
+        }
+
+        // ── Public API ─────────────────────────────────────────
+        public void SetPhase(Phase phase, int seatIndex, int turnNumber)
+        {
+            _currentPhase = phase;
+
+            for (int i = 0; i < stepButtons.Length; i++)
+                stepButtons[i]?.SetActive(i == (int)phase);
+
+            if (activePlayerLabel)
+                activePlayerLabel.text = seatIndex == 0 ? "Your Turn" : $"Seat {seatIndex}'s Turn";
+
+            if (turnNumberLabel)
+                turnNumberLabel.text = $"Turn {turnNumber}";
+        }
+
+        public Phase CurrentPhase => _currentPhase;
+
+        // ── Debug (editor only) ──────────────────────────────────
+#if UNITY_EDITOR
+        private void Update()
+        {
+            if (Input.GetKeyDown(KeyCode.Space))
+            {
+                int next = ((int)_currentPhase + 1) % System.Enum.GetValues(typeof(Phase)).Length;
+                SetPhase((Phase)next, 0, GameStateManager.Instance?.TurnNumber ?? 1);
+            }
+        }
+#endif
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/PoisonCounter.cs

@@ -0,0 +1,49 @@
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Tracks poison counters for a seat (0-10).
+    /// Activates pip toggles and triggers elimination at 10.
+    /// </summary>
+    public class PoisonCounter : MonoBehaviour
+    {
+        [SerializeField] private int       seatIndex;
+        [SerializeField] private Toggle[]  pips;          // 10 Toggle GameObjects
+        [SerializeField] private TMP_Text  countLabel;
+        [SerializeField] private Button    addPoisonBtn;
+        [SerializeField] private Button    removePoisonBtn;
+
+        private int _count = 0;
+
+        private void Start()
+        {
+            addPoisonBtn?.onClick.AddListener(()    => AddPoison(1));
+            removePoisonBtn?.onClick.AddListener(() => AddPoison(-1));
+            Refresh();
+        }
+
+        public void AddPoison(int delta)
+        {
+            _count = Mathf.Clamp(_count + delta, 0, 10);
+            Refresh();
+            if (_count >= 10)
+                GameStateManager.Instance?.EliminatePlayer(seatIndex, "poison");
+        }
+
+        public void SetPoison(int value)
+        {
+            _count = Mathf.Clamp(value, 0, 10);
+            Refresh();
+        }
+
+        private void Refresh()
+        {
+            if (countLabel) countLabel.text = _count.ToString();
+            for (int i = 0; i < pips.Length; i++)
+                if (pips[i] != null) pips[i].isOn = i < _count;
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/StackItemView.cs

@@ -0,0 +1,54 @@
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Visual row for a single item on the stack.
+    /// Shows card/ability name, caster seat color, stack position, and targets.
+    /// </summary>
+    public class StackItemView : MonoBehaviour
+    {
+        [SerializeField] private TMP_Text   cardNameLabel;
+        [SerializeField] private TMP_Text   casterLabel;
+        [SerializeField] private TMP_Text   targetsLabel;
+        [SerializeField] private TMP_Text   stackPositionLabel;
+        [SerializeField] private Image      seatColorStrip;
+
+        private static readonly Color[] SeatColors =
+        {
+            new Color(0.2f, 0.6f, 1f),   // seat 0 — blue (human)
+            new Color(1f,  0.4f, 0.4f),  // seat 1 — red
+            new Color(0.4f, 1f, 0.4f),   // seat 2 — green
+            new Color(1f,  0.85f, 0.2f)  // seat 3 — gold
+        };
+
+        public void Bind(StackZoneController.StackItem item, int displayPosition)
+        {
+            if (cardNameLabel)
+                cardNameLabel.text = item.isAbility ? $"⚡ {item.cardName}" : item.cardName;
+
+            if (casterLabel)
+                casterLabel.text = item.casterSeat == 0 ? "You" : $"Seat {item.casterSeat}";
+
+            if (seatColorStrip)
+            {
+                int seat = Mathf.Clamp(item.casterSeat, 0, SeatColors.Length - 1);
+                seatColorStrip.color = SeatColors[seat];
+            }
+
+            if (stackPositionLabel)
+                stackPositionLabel.text = displayPosition == 0 ? "[TOP]" : $"[{displayPosition}]";
+
+            if (targetsLabel)
+            {
+                if (item.targets != null && item.targets.Count > 0)
+                    targetsLabel.text = "\u2192 " + string.Join(", ", item.targets);
+                else
+                    targetsLabel.text = "";
+            }
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/StackZoneController.cs

@@ -0,0 +1,72 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+using TMPro;
+using Newtonsoft.Json;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Displays the active spell/ability stack (LIFO order, top of stack shown first).
+    /// Hidden when stack is empty. Subscribes to GameStateManager.OnStackUpdated.
+    /// </summary>
+    public class StackZoneController : MonoBehaviour
+    {
+        [SerializeField] private GameObject stackPanel;
+        [SerializeField] private Transform  stackItemParent;  // VerticalLayoutGroup
+        [SerializeField] private GameObject stackItemPrefab;
+        [SerializeField] private TMP_Text   stackCountLabel;
+
+        private readonly List<GameObject> _itemGOs = new();
+
+        // ── Lifecycle ───────────────────────────────────────────
+        private void Start()
+        {
+            if (GameStateManager.Instance != null)
+                GameStateManager.Instance.OnStackUpdated += SetStack;
+            SetStack(new List<StackItem>());
+        }
+
+        private void OnDestroy()
+        {
+            if (GameStateManager.Instance != null)
+                GameStateManager.Instance.OnStackUpdated -= SetStack;
+        }
+
+        // ── Public API ─────────────────────────────────────────
+        public void SetStack(List<StackItem> items)
+        {
+            // Clear existing rows
+            foreach (var go in _itemGOs) if (go) Destroy(go);
+            _itemGOs.Clear();
+
+            bool hasItems = items != null && items.Count > 0;
+            if (stackPanel) stackPanel.SetActive(hasItems);
+
+            if (stackCountLabel)
+                stackCountLabel.text = hasItems ? $"Stack ({items.Count})" : "";
+
+            if (!hasItems) return;
+
+            // LIFO — iterate in reverse so top of stack appears first
+            for (int i = items.Count - 1; i >= 0; i--)
+            {
+                var go = Instantiate(stackItemPrefab, stackItemParent);
+                go.SetActive(true);
+                var view = go.GetComponent<StackItemView>();
+                view?.Bind(items[i], items.Count - 1 - i);
+                _itemGOs.Add(go);
+            }
+        }
+
+        // ── Serializable stack item (shared with GameState) ───────────
+        [Serializable]
+        public class StackItem
+        {
+            [JsonProperty("card_name")]  public string cardName;
+            [JsonProperty("caster_seat")] public int casterSeat;
+            [JsonProperty("targets")]   public List<string> targets;
+            [JsonProperty("is_ability")] public bool isAbility;
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/TODO.md

@@ -0,0 +1,99 @@
+# Battleground UI — Task Tracker
+> Created: 2026-03-28  
+> Updated: 2026-03-29 — all 14 issues complete
+> Branch: `feat/battleground-ui`
+
+All issues below are part of the **4-player Commander Battleground** Unity 3D UI build.
+Build in the numbered order — each step is independently testable before the next.
+
+---
+
+## Build Order Checklist
+
+| # | Issue | Script(s) | Needs Backend? | Status |
+|---|-------|-----------|----------------|--------|
+| 1 | [#138 — Battleground.unity scene + 4-seat layout](https://github.com/KoalaTrapLord/commander-ai-lab/issues/138) | `BattlegroundController.cs`, `GameStateManager.cs` | No | ✅ |
+| 2 | [#139 — LifeTrackerWidget + CommanderDamageRow + Poison](https://github.com/KoalaTrapLord/commander-ai-lab/issues/139) | `LifeTrackerWidget.cs`, `CommanderDamageRow.cs`, `PoisonCounter.cs` | No | ✅ |
+| 3 | [#140 — PhaseTrackerWidget + PhaseStepButton](https://github.com/KoalaTrapLord/commander-ai-lab/issues/140) | `PhaseTrackerWidget.cs`, `PhaseStepButton.cs` | No | ✅ |
+| 4 | [#141 — TurnOrderBar + TurnOrderPill](https://github.com/KoalaTrapLord/commander-ai-lab/issues/141) | `TurnOrderBar.cs`, `TurnOrderPill.cs` | No | ✅ |
+| 5 | [#142 — CardZone + CardView](https://github.com/KoalaTrapLord/commander-ai-lab/issues/142) | `CardZone.cs`, `CardView.cs` + `CardModel` runtime fields | ImageCache only | ✅ |
+| 6 | [#143 — CommanderZoneWidget](https://github.com/KoalaTrapLord/commander-ai-lab/issues/143) | `CommanderZoneWidget.cs` + `ImageCache.LoadArtCrop()` | ImageCache only | ✅ |
+| 7 | [#144 — Token System](https://github.com/KoalaTrapLord/commander-ai-lab/issues/144) | `TokenModel.cs`, `TokenPanelController.cs`, `TokenRowView.cs` | No | ✅ |
+| 8 | [#146 — StackZoneController + ManaPoolDisplay](https://github.com/KoalaTrapLord/commander-ai-lab/issues/146) | `StackZoneController.cs`, `ManaPoolDisplay.cs` | No (events only) | ✅ |
+| 9 | [#147 — LobbySetupModal + ZoneViewerModal](https://github.com/KoalaTrapLord/commander-ai-lab/issues/147) | `LobbySetupModal.cs`, `ZoneViewerModal.cs` | `/api/decks`, `/api/game/start` | ✅ |
+| 10 | [#148 — GameStateManager + GameState POCOs](https://github.com/KoalaTrapLord/commander-ai-lab/issues/148) | `GameStateManager.cs`, `GameState.cs` | No | ✅ |
+| 11 | [#149 — GameWebSocketClient](https://github.com/KoalaTrapLord/commander-ai-lab/issues/149) | `GameWebSocketClient.cs` | Yes — `/ws/game` | ✅ |
+| 12 | [#145 — HumanActionBar](https://github.com/KoalaTrapLord/commander-ai-lab/issues/145) | `HumanActionBar.cs`, `ApiClient.PostGameAction()` | Yes — `/api/game/action` | ✅ |
+| 13 | [#150 — EliminationHandler + Grayscale Shader](https://github.com/KoalaTrapLord/commander-ai-lab/issues/150) | `EliminationHandler.cs`, `EliminatedGrayscale` ShaderGraph | No | ✅ |
+| 14 | [#151 — SimulationController: Play Live button](https://github.com/KoalaTrapLord/commander-ai-lab/issues/151) | `SimulationController.cs` (modify) | No | ✅ |
+
+---
+
+## All Files Committed
+
+### `Assets/Scripts/UI/Battleground/` (new folder)
+- ✅ `BattlegroundController.cs` — scene orchestrator, seat rotations, event subscriptions
+- ✅ `GameStateManager.cs` — singleton event hub
+- ✅ `LifeTrackerWidget.cs` — life +/- with history + danger flash
+- ✅ `CommanderDamageRow.cs` — 4-pip commander damage tracker per seat
+- ✅ `PoisonCounter.cs` — 10-pip poison tracker
+- ✅ `PhaseTrackerWidget.cs` — 13-step phase strip, Space key debug advance
+- ✅ `PhaseStepButton.cs` — individual phase pill (color + scale)
+- ✅ `TurnOrderBar.cs` — animated seat border slider
+- ✅ `TurnOrderPill.cs` — per-seat pill with name, life, eliminated state
+- ✅ `CardZone.cs` — zone container (add/remove/clear CardView children)
+- ✅ `CardView.cs` — card visual (art, tapped rotation, face-down, summoning sick)
+- ✅ `CommanderZoneWidget.cs` — art crop, cast count, tax (+2 per cast)
+- ✅ `TokenPanelController.cs` — token creation panel
+- ✅ `TokenRowView.cs` — token row (qty, tap, counters, delete)
+- ✅ `StackZoneController.cs` — LIFO stack display, hidden when empty
+- ✅ `StackItemView.cs` — individual stack item row
+- ✅ `ManaPoolDisplay.cs` — 6-pip mana display, hides zero labels
+- ✅ `LobbySetupModal.cs` — 4-seat lobby config, loads decks from API, POSTs to /api/game/start
+- ✅ `ZoneViewerModal.cs` — fullscreen graveyard/exile viewer with search filter
+- ✅ `HumanActionBar.cs` — priority-gated action buttons + targeting mode
+- ✅ `EliminationHandler.cs` — overlay + grayscale material on elimination
+
+### `Assets/Scripts/Models/`
+- ✅ `GameState.cs` — `GameState` + `SeatState` POCOs
+- ✅ `TokenModel.cs` — token data model
+- ✅ `CardModel.cs` — modified: added `[NonSerialized]` runtime state + `BattleZone` enum
+
+### `Assets/Scripts/Services/`
+- ✅ `ImageCache.cs` — modified: added `LoadCard(RawImage)` + `LoadArtCrop(name, RawImage)`
+- ✅ `GameWebSocketClient.cs` — WS connect/reconnect, ping, ConcurrentQueue main-thread dispatch
+- ✅ `ApiClient.cs` — modified: added `PostGameAction()` + `PostGameStart()`
+
+### `Assets/Scenes/`
+- ✅ `Battleground.unity` — new scene
+
+### `Assets/Materials/`
+- ✅ `EliminatedGrayscale` — URP Shader Graph
+
+### Modified Existing Files
+- ✅ `SimulationController.cs` — Play Live button + `OnPlayLive()` + `BuildSeatsJson()`
+- ✅ `MainMenuController.cs` — Play Live nav button
+
+---
+
+## Backend Endpoints Required
+
+These Python routes must exist before end-to-end testing:
+
+| Endpoint | Used By | Status |
+|----------|---------|--------|
+| `GET /api/decks` | `LobbySetupModal` | verify |
+| `POST /api/game/start` | `LobbySetupModal` | verify |
+| `POST /api/game/action` | `HumanActionBar` | verify |
+| `WS /ws/game` | `GameWebSocketClient` | verify (PR #107) |
+
+---
+
+## Architecture Notes
+
+- **`GameStateManager`** is the singleton event hub — all UI widgets subscribe to its events, never poll
+- **`GameWebSocketClient`** receives server push messages and routes them to `GameStateManager.ApplyServerEvent()`
+- **Canvas mode**: Screen Space — Camera (not World Space) for crisp TMP rendering
+- **Seat rotation**: AI panels rotated -90°, 180°, 90° via `localEulerAngles` so text/buttons face the right direction
+- **Backend WS**: connect to `ws://localhost:8080/ws/game` (configurable via `PlayerPrefs["ServerUrl"]`)
+- **Space key** in Play Mode advances the phase strip for isolated testing without WebSocket

unity-client/Assets/Scripts/UI/Battleground/TokenPanelController.cs

@@ -0,0 +1,86 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+using CommanderAILab.Models;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Token creation and tracking panel in the BattlefieldCenter.
+    /// Human creates tokens manually; AI tokens are added via AddToken() from server events.
+    /// </summary>
+    public class TokenPanelController : MonoBehaviour
+    {
+        [Header("Creation Row")]
+        [SerializeField] private TMP_InputField nameInput;
+        [SerializeField] private TMP_InputField powerInput;
+        [SerializeField] private TMP_InputField toughnessInput;
+        [SerializeField] private TMP_InputField qtyInput;
+        [SerializeField] private Button         createBtn;
+
+        [Header("List")]
+        [SerializeField] private Transform  tokenListParent;
+        [SerializeField] private GameObject tokenRowPrefab;
+
+        private readonly List<TokenModel>   _tokens    = new();
+        private readonly List<TokenRowView> _rowViews  = new();
+
+        // ── Lifecycle ───────────────────────────────────────────
+        private void Start() => createBtn.onClick.AddListener(OnCreateToken);
+
+        // ── Token management ────────────────────────────────────
+        private void OnCreateToken()
+        {
+            string tokenName = nameInput?.text?.Trim();
+            if (string.IsNullOrEmpty(tokenName)) return;
+
+            int.TryParse(qtyInput?.text, out int qty);
+            qty = Mathf.Max(1, qty);
+
+            var token = new TokenModel
+            {
+                id         = Guid.NewGuid().ToString(),
+                name       = tokenName,
+                power      = powerInput?.text?.Trim() ?? "",
+                toughness  = toughnessInput?.text?.Trim() ?? "",
+                ownerSeat  = 0,
+                qty        = qty
+            };
+
+            AddToken(token);
+
+            // Clear inputs
+            if (nameInput)      nameInput.text      = "";
+            if (powerInput)     powerInput.text     = "";
+            if (toughnessInput) toughnessInput.text = "";
+            if (qtyInput)       qtyInput.text       = "1";
+        }
+
+        public void AddToken(TokenModel token)
+        {
+            _tokens.Add(token);
+            var go   = Instantiate(tokenRowPrefab, tokenListParent);
+            var view = go.GetComponent<TokenRowView>();
+            if (view != null)
+            {
+                view.Bind(token, RemoveToken);
+                _rowViews.Add(view);
+            }
+        }
+
+        private void RemoveToken(TokenModel token)
+        {
+            int idx = _tokens.IndexOf(token);
+            if (idx < 0) return;
+
+            _tokens.RemoveAt(idx);
+            var view = _rowViews[idx];
+            _rowViews.RemoveAt(idx);
+            if (view != null) Destroy(view.gameObject);
+        }
+
+        public IReadOnlyList<TokenModel> Tokens => _tokens;
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/TokenRowView.cs

@@ -0,0 +1,117 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+using CommanderAILab.Models;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// A single token row in TokenPanelController's list.
+    /// Supports qty +/-, tap all, counter editing, and removal.
+    /// </summary>
+    public class TokenRowView : MonoBehaviour
+    {
+        [Header("Labels")]
+        [SerializeField] private TMP_Text nameLabel;
+        [SerializeField] private TMP_Text ptLabel;
+        [SerializeField] private TMP_Text qtyLabel;
+        [SerializeField] private TMP_Text tappedLabel;
+
+        [Header("Buttons")]
+        [SerializeField] private Button qtyPlusBtn;
+        [SerializeField] private Button qtyMinusBtn;
+        [SerializeField] private Button tapAllBtn;
+        [SerializeField] private Button deleteBtn;
+
+        [Header("Counter Editor")]
+        [SerializeField] private GameObject       counterEditorPanel;
+        [SerializeField] private TMP_Dropdown     counterTypeDropdown;
+        [SerializeField] private Button           counterAddBtn;
+        [SerializeField] private Button           counterRemoveBtn;
+        [SerializeField] private TMP_Text         counterSummaryLabel;
+        [SerializeField] private Button           toggleCounterEditorBtn;
+
+        private static readonly List<string> CounterTypes =
+            new() { "+1/+1", "-1/-1", "loyalty", "charge", "quest", "time" };
+
+        private TokenModel            _token;
+        private Action<TokenModel>    _onDelete;
+
+        // ── Binding ───────────────────────────────────────────
+        public void Bind(TokenModel token, Action<TokenModel> onDelete)
+        {
+            _token    = token;
+            _onDelete = onDelete;
+
+            // Wire buttons
+            qtyPlusBtn ?.onClick.AddListener(() => AdjustQty(+1));
+            qtyMinusBtn?.onClick.AddListener(() => AdjustQty(-1));
+            tapAllBtn  ?.onClick.AddListener(TapAll);
+            deleteBtn  ?.onClick.AddListener(() => _onDelete?.Invoke(_token));
+            toggleCounterEditorBtn?.onClick.AddListener(ToggleCounterEditor);
+            counterAddBtn   ?.onClick.AddListener(() => AdjustCounter(+1));
+            counterRemoveBtn?.onClick.AddListener(() => AdjustCounter(-1));
+
+            // Populate counter type dropdown
+            if (counterTypeDropdown != null)
+            {
+                counterTypeDropdown.ClearOptions();
+                counterTypeDropdown.AddOptions(CounterTypes);
+            }
+
+            if (counterEditorPanel) counterEditorPanel.SetActive(false);
+            RefreshDisplay();
+        }
+
+        // ── Actions ────────────────────────────────────────────
+        private void AdjustQty(int delta)
+        {
+            _token.qty = Mathf.Max(0, _token.qty + delta);
+            if (_token.qty == 0) { _onDelete?.Invoke(_token); return; }
+            RefreshDisplay();
+        }
+
+        private void TapAll()
+        {
+            _token.isTapped = !_token.isTapped;
+            RefreshDisplay();
+        }
+
+        private void ToggleCounterEditor()
+        {
+            if (counterEditorPanel)
+                counterEditorPanel.SetActive(!counterEditorPanel.activeSelf);
+        }
+
+        private void AdjustCounter(int delta)
+        {
+            if (counterTypeDropdown == null) return;
+            string counterType = CounterTypes[Mathf.Clamp(counterTypeDropdown.value, 0, CounterTypes.Count - 1)];
+            _token.counters.TryGetValue(counterType, out int current);
+            int next = Mathf.Max(0, current + delta);
+            if (next == 0) _token.counters.Remove(counterType);
+            else           _token.counters[counterType] = next;
+            RefreshDisplay();
+        }
+
+        // ── Display ────────────────────────────────────────────
+        private void RefreshDisplay()
+        {
+            if (nameLabel)   nameLabel.text  = _token.name;
+            if (ptLabel)     ptLabel.text    = _token.PTString;
+            if (qtyLabel)    qtyLabel.text   = $"×{_token.qty}";
+            if (tappedLabel) tappedLabel.text = _token.isTapped ? "[Tapped]" : "";
+
+            // Counter summary
+            if (counterSummaryLabel)
+            {
+                var parts = new System.Text.StringBuilder();
+                foreach (var kv in _token.counters)
+                    parts.Append($"{kv.Key}:{kv.Value} ");
+                counterSummaryLabel.text = parts.Length > 0 ? parts.ToString().Trim() : "No counters";
+            }
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/TurnOrderBar.cs

@@ -0,0 +1,86 @@
+using UnityEngine;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Horizontal strip of 4 TurnOrderPills at the top of BattlefieldCenter.
+    /// Animates an active border sliding to the current seat's pill on turn change.
+    /// Subscribes to GameStateManager.OnTurnChanged.
+    /// </summary>
+    public class TurnOrderBar : MonoBehaviour
+    {
+        [SerializeField] private TurnOrderPill[] pills;        // length 4
+        [SerializeField] private RectTransform   activeBorder; // sliding highlight rect
+        [SerializeField] private float           slideDuration = 0.25f;
+
+        private int _activeSeat = 0;
+
+        // ── Lifecycle ───────────────────────────────────────────
+        private void Start()
+        {
+            if (GameStateManager.Instance != null)
+            {
+                GameStateManager.Instance.OnTurnChanged  += SetActiveSeat;
+                GameStateManager.Instance.OnLifeChanged  += OnLifeChanged;
+                GameStateManager.Instance.OnPlayerEliminated += OnPlayerEliminated;
+            }
+            SetActiveSeat(0);
+        }
+
+        private void OnDestroy()
+        {
+            if (GameStateManager.Instance == null) return;
+            GameStateManager.Instance.OnTurnChanged      -= SetActiveSeat;
+            GameStateManager.Instance.OnLifeChanged      -= OnLifeChanged;
+            GameStateManager.Instance.OnPlayerEliminated -= OnPlayerEliminated;
+        }
+
+        // ── Public API ─────────────────────────────────────────
+        public void SetActiveSeat(int seatIndex)
+        {
+            _activeSeat = seatIndex;
+            for (int i = 0; i < pills.Length; i++)
+                pills[i]?.SetActive(i == seatIndex);
+
+            AnimateBorderToPill(seatIndex);
+        }
+
+        // ── Internal ──────────────────────────────────────────
+        private void AnimateBorderToPill(int seatIndex)
+        {
+            if (activeBorder == null || pills == null || seatIndex >= pills.Length) return;
+            if (pills[seatIndex] == null) return;
+
+            var targetPos = (pills[seatIndex].transform as RectTransform)?.anchoredPosition
+                            ?? pills[seatIndex].transform.localPosition;
+
+            StopAllCoroutines();
+            StartCoroutine(SlideBorder(targetPos));
+        }
+
+        private System.Collections.IEnumerator SlideBorder(Vector2 targetPos)
+        {
+            var start = activeBorder.anchoredPosition;
+            float elapsed = 0f;
+            while (elapsed < slideDuration)
+            {
+                elapsed += Time.deltaTime;
+                float t = Mathf.SmoothStep(0f, 1f, elapsed / slideDuration);
+                activeBorder.anchoredPosition = Vector2.Lerp(start, targetPos, t);
+                yield return null;
+            }
+            activeBorder.anchoredPosition = targetPos;
+        }
+
+        private void OnLifeChanged(int seatIndex, int newLife)
+        {
+            if (seatIndex < pills.Length) pills[seatIndex]?.UpdateLife(newLife);
+        }
+
+        private void OnPlayerEliminated(int seatIndex, string reason)
+        {
+            if (seatIndex < pills.Length) pills[seatIndex]?.SetEliminated();
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/TurnOrderPill.cs

@@ -0,0 +1,57 @@
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// A single seat pill inside TurnOrderBar.
+    /// Shows player name, current life, and highlights when it is that seat's turn.
+    /// </summary>
+    public class TurnOrderPill : MonoBehaviour
+    {
+        [SerializeField] private TMP_Text   playerNameLabel;
+        [SerializeField] private TMP_Text   lifeLabel;
+        [SerializeField] private Image      pillBackground;
+        [SerializeField] private GameObject youBadge;          // "YOU" label, only visible on seat 0
+
+        [Header("Colors")]
+        [SerializeField] private Color activeColor   = new Color(1f, 0.85f, 0f);
+        [SerializeField] private Color inactiveColor = new Color(0.25f, 0.25f, 0.25f);
+        [SerializeField] private Color eliminatedColor = new Color(0.4f, 0.4f, 0.4f, 0.5f);
+
+        private bool _isEliminated;
+
+        public void SetPlayerName(string playerName)
+        {
+            if (playerNameLabel) playerNameLabel.text = playerName;
+        }
+
+        public void UpdateLife(int life)
+        {
+            if (lifeLabel) lifeLabel.text = life.ToString();
+        }
+
+        public void ShowYouBadge(bool show)
+        {
+            if (youBadge) youBadge.SetActive(show);
+        }
+
+        public void SetActive(bool active)
+        {
+            if (_isEliminated) return;
+            if (pillBackground) pillBackground.color = active ? activeColor : inactiveColor;
+        }
+
+        public void SetEliminated()
+        {
+            _isEliminated = true;
+            if (pillBackground) pillBackground.color = eliminatedColor;
+            if (playerNameLabel)
+            {
+                playerNameLabel.fontStyle = TMPro.FontStyles.Strikethrough;
+                playerNameLabel.color     = Color.gray;
+            }
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/ZoneViewerModal.cs

@@ -0,0 +1,53 @@
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Full-screen overlay showing all cards in a particular zone (graveyard, exile, etc.).
+    /// Opened by clicking zone count badges on each seat panel.
+    /// </summary>
+    public class ZoneViewerModal : MonoBehaviour
+    {
+        [Header("References")]
+        [SerializeField] private TMP_Text   titleLabel;
+        [SerializeField] private Transform  cardGrid;       // GridLayoutGroup
+        [SerializeField] private GameObject cardPrefab;     // CardView prefab
+        [SerializeField] private Button     closeButton;
+
+        private readonly List<GameObject> _cardGOs = new();
+
+        private void Start() => closeButton?.onClick.AddListener(Close);
+
+        // ── Open ─────────────────────────────────────────────────
+        public void Open(string zoneName, CardZone zone)
+        {
+            if (titleLabel) titleLabel.text = $"{zoneName} ({zone.Count} cards)";
+
+            foreach (var go in _cardGOs) if (go) Destroy(go);
+            _cardGOs.Clear();
+
+            foreach (var view in zone.Cards)
+            {
+                if (view?.Model == null) continue;
+                var go = Instantiate(cardPrefab, cardGrid);
+                go.SetActive(true);
+                var cv = go.GetComponent<CardView>();
+                cv?.Bind(view.Model, false);
+                _cardGOs.Add(go);
+            }
+
+            gameObject.SetActive(true);
+        }
+
+        // ── Close ───────────────────────────────────────────────
+        public void Close()
+        {
+            foreach (var go in _cardGOs) if (go) Destroy(go);
+            _cardGOs.Clear();
+            gameObject.SetActive(false);
+        }
+    }
+}

unity-client/Assets/Scripts/UI/SimulationController.cs

@@ -15,6 +15,7 @@ namespace CommanderAILab.UI
     /// <summary>
     /// Simulator scene — configure and run multi-player simulations,
     /// poll status, display results per deck.
+    /// Also provides a Play Live button that routes to the Battleground scene.
     /// </summary>
     public class SimulationController : MonoBehaviour
     {
@@ -22,6 +23,8 @@ namespace CommanderAILab.UI
         [Header("Navigation")]
         [SerializeField] private Button backButton;
         [SerializeField] private Button startSimButton;
+        /// <summary>Routes to the Battleground scene for a live 4-player game.</summary>
+        [SerializeField] private Button playLiveButton;
 
         // ── Config Panel ──────────────────────────────────────────────────────
         [Header("Config")]
@@ -74,6 +77,9 @@ namespace CommanderAILab.UI
             startSimButton.onClick.AddListener(OnStartSim);
             retryButton.onClick.AddListener(OnStartSim);
 
+            // Play Live: save current deck selections and load Battleground scene
+            playLiveButton?.onClick.AddListener(OnPlayLive);
+
             numPlayersSlider.minValue = 2;
             numPlayersSlider.maxValue = 4;
             numPlayersSlider.wholeNumbers = true;
@@ -83,12 +89,10 @@ namespace CommanderAILab.UI
 
             errorPanel.SetActive(false);
 
-            // Check for a deck exported from DeckBuilder
             string simDeck = PlayerPrefs.GetString("SimDeck", "");
             if (!string.IsNullOrEmpty(simDeck))
             {
                 PlayerPrefs.DeleteKey("SimDeck");
-                // Pre-populate deck dropdown 0 after decks load — stored for later
                 PlayerPrefs.SetString("_SimDeckPending", simDeck);
             }
 
@@ -96,6 +100,29 @@ namespace CommanderAILab.UI
             LoadAiProfiles();
         }
 
+        // ── Play Live ─────────────────────────────────────────────────────────
+        private void OnPlayLive()
+        {
+            // Persist current deck selections so LobbySetupModal can pre-populate
+            var seats = new List<object>();
+            void AddSeat(TMP_Dropdown dd, bool isHuman, int seatIdx)
+            {
+                string deckName = "";
+                if (dd != null && dd.value > 0 && (dd.value - 1) < _decks.Count)
+                    deckName = _decks[dd.value - 1].name;
+                seats.Add(new { isHuman, deckName, aiStyle = "Aggro" });
+            }
+
+            AddSeat(deckDropdown0, true,  0);
+            AddSeat(deckDropdown1, false, 1);
+            AddSeat(deckDropdown2, false, 2);
+            AddSeat(deckDropdown3, false, 3);
+
+            PlayerPrefs.SetString("BattleSeats", JsonConvert.SerializeObject(seats));
+            PlayerPrefs.Save();
+            SceneManager.LoadScene("Battleground");
+        }
+
         // ── Player Count ──────────────────────────────────────────────────────
         private void OnNumPlayersChanged(float value)
         {
@@ -103,7 +130,6 @@ namespace CommanderAILab.UI
             if (numPlayersLabel != null)
                 numPlayersLabel.text = $"Players: {count}";
 
-            // Show/hide optional deck dropdowns based on count
             if (deckDropdown2 != null) deckDropdown2.gameObject.SetActive(count >= 3);
             if (deckDropdown3 != null) deckDropdown3.gameObject.SetActive(count >= 4);
         }
@@ -143,14 +169,12 @@ namespace CommanderAILab.UI
             Fill(deckDropdown2);
             Fill(deckDropdown3);
 
-            // Apply any pending deck from DeckBuilder export
             string pending = PlayerPrefs.GetString("_SimDeckPending", "");
             if (!string.IsNullOrEmpty(pending))
             {
                 PlayerPrefs.DeleteKey("_SimDeckPending");
                 try
                 {
-                    // Try to match by name from the JSON
                     var exported = JsonConvert.DeserializeObject<LabDeckEntry>(pending);
                     if (exported != null && !string.IsNullOrEmpty(exported.name))
                     {
@@ -179,7 +203,6 @@ namespace CommanderAILab.UI
                 },
                 err =>
                 {
-                    // Non-fatal: profiles may not be available yet
                     _profiles = new List<AiProfile>();
                     PopulateProfileDropdown();
                 });
@@ -203,7 +226,6 @@ namespace CommanderAILab.UI
 
             int numPlayers = Mathf.RoundToInt(numPlayersSlider.value);
 
-            // Collect selected deck names (index 0 = "-- Select Deck --")
             var selectedDecks = new List<string>();
             void TryAdd(TMP_Dropdown dd)
             {
@@ -292,7 +314,6 @@ namespace CommanderAILab.UI
 
                 bool done = false;
                 string errorMsg = null;
-                SimStatusModel latestStatus = null;
 
                 _api.GetSimStatus(batchId,
                     json =>
@@ -301,7 +322,6 @@ namespace CommanderAILab.UI
                         {
                             var status = JsonConvert.DeserializeObject<SimStatusModel>(json);
                             if (status == null) { done = true; errorMsg = "Empty status response."; return; }
-                            latestStatus = status;
 
                             if (!string.IsNullOrEmpty(status.error))
                             {
@@ -332,7 +352,6 @@ namespace CommanderAILab.UI
                     },
                     err => { done = true; errorMsg = err; });
 
-                // Wait one frame so callbacks have fired
                 yield return null;
 
                 if (!string.IsNullOrEmpty(errorMsg))
@@ -424,7 +443,7 @@ namespace CommanderAILab.UI
             errorText.text = msg;
         }
 
-        // ── Helper Models (private inner classes) ─────────────────────────────
+        // ── Helper Models ─────────────────────────────────────────────────────
         [Serializable] private class DecksWrapper    { public List<LabDeckEntry> decks; }
         [Serializable] private class LabDeckEntry    { public string name; public string source; public string commander; }
         [Serializable] private class ProfilesWrapper { public List<AiProfile> profiles; }
@@ -435,6 +454,13 @@ namespace CommanderAILab.UI
             public bool useLearnedPolicy; public string policyStyle;
             public int seed; public int clock;
         }
+        [Serializable] private class SimStartResponse { public string batchId; }
+        [Serializable] private class SimStatusModel
+        {
+            public bool   running; public int total; public int completed;
+            public int    totalGames; public int gamesCompleted;
+            public float  elapsedMs; public float simsPerSec; public string error;
+        }
         [Serializable] private class SimResult  { public Summary summary; }
         [Serializable] private class Summary    { public List<ResultEntry> perDeck; }
         [Serializable] private class ResultEntry { public string deckName; public float winRate; public int wins; public int losses; }