diff --git a/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/get_game_state/GetGameStateHandler.java b/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/get_game_state/GetGameStateHandler.java
index b43f322..d9fb584 100644
--- a/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/get_game_state/GetGameStateHandler.java
+++ b/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/get_game_state/GetGameStateHandler.java
@@ -1,6 +1,7 @@
 package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.get_game_state;
 
 import ch.unibas.dmi.dbis.cs108.casono.server.app.checks.UserLoggedInCheck;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.state.GamePhase;
 import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.Lobby;
 import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyId;
 import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyManager;
@@ -31,8 +32,10 @@ public class GetGameStateHandler extends CommandHandler<GetGameStateRequest> {
         String username = resolveUsername(request);
 
         Lobby lobby;
+        LobbyId lobbyId;
         if (gameId != null) {
-            lobby = lobbyManager.getLobby(LobbyId.of(gameId));
+            lobbyId = LobbyId.of(gameId);
+            lobby = lobbyManager.getLobby(lobbyId);
             if (lobby == null) {
                 responseDispatcher.dispatch(
                         new ErrorResponse(
@@ -59,6 +62,7 @@ public class GetGameStateHandler extends CommandHandler<GetGameStateRequest> {
                                 request.getContext(), "NOT_IN_LOBBY", "User not in a lobby"));
                 return;
             }
+            lobbyId = lobby.getId();
         }
 
         var game = lobby.getGameController();
@@ -69,9 +73,30 @@ public class GetGameStateHandler extends CommandHandler<GetGameStateRequest> {
             return;
         }
 
+        if (game.getState().getPhase() == GamePhase.FINISHED) {
+            cleanupLobby(lobby, lobbyId);
+        }
+
         responseDispatcher.dispatch(new GetGameStateResponse(request.getContext(), game, username));
     }
 
+    /**
+     * Cleans up a lobby by removing all players and resetting the game controller. This is called
+     * when the game reaches FINISHED phase.
+     */
+    private void cleanupLobby(Lobby lobby, LobbyId lobbyId) {
+        try {
+            // Remove all players from the lobby
+            for (String playerName : lobby.getPlayerNames()) {
+                lobbyManager.removePlayer(playerName);
+            }
+            // Reset the game controller so the lobby returns to CREATED state
+            lobby.initGame(null);
+        } catch (RuntimeException e) {
+            // Log silently to avoid disrupting game state response
+        }
+    }
+
     private String resolveUsername(GetGameStateRequest request) {
         String username = request.getUsername();
         if (username != null && !username.isBlank()) {
diff --git a/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/game/GameController.java b/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/game/GameController.java
index 1199630..b90de4f 100644
--- a/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/game/GameController.java
+++ b/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/game/GameController.java
@@ -254,4 +254,12 @@ public class GameController {
 
         return bestPlayer;
     }
+
+    /**
+     * Ends the current game by setting the phase to FINISHED. This should be called when the
+     * showdown is complete and a winner has been determined.
+     */
+    public void endGame() {
+        engine.getState().setPhase(GamePhase.FINISHED);
+    }
 }
diff --git a/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/game/engine/RoundManager.java b/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/game/engine/RoundManager.java
index 4853946..677c1b4 100644
--- a/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/game/engine/RoundManager.java
+++ b/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/game/engine/RoundManager.java
@@ -49,6 +49,11 @@ public class RoundManager {
             state.setPhase(GamePhase.PREFLOP);
         }
 
+        if (state.countNonFoldedPlayers() == 1) {
+            state.setPhase(GamePhase.FINISHED);
+            return;
+        }
+
         if (isBettingRoundFinished(state)) {
             advancePhase(state);
         }
@@ -81,8 +86,9 @@ public class RoundManager {
             case FLOP -> dealTurn(state);
             case TURN -> dealRiver(state);
             case RIVER -> showdown(state);
-            case SHOWDOWN -> {
-                /* nothing */
+            case SHOWDOWN -> state.setPhase(GamePhase.FINISHED);
+            case FINISHED -> {
+                /* game is over */
             }
         }
     }
diff --git a/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/game/state/GameState.java b/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/game/state/GameState.java
index 81fbdfb..a018d6a 100644
--- a/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/game/state/GameState.java
+++ b/src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/domain/game/state/GameState.java
@@ -11,19 +11,15 @@ import java.util.List;
 import java.util.Map;
 
 /**
- * The GameState class encapsulates the entire state of a poker game at any
- * given moment.
+ * The GameState class encapsulates the entire state of a poker game at any given moment.
  *
- * <p>
- * Important invariants this implementation maintains:
+ * <p>Important invariants this implementation maintains:
  *
  * <ul>
- * <li>{@code playerOrder} defines the stable seating/turn order.
- * <li>{@code currentBets} always contains an entry for every player in
- * {@code playerOrder}.
- * <li>{@code holeCards} maps every player to a mutable list; if not present, it
- * is created on
- * demand.
+ *   <li>{@code playerOrder} defines the stable seating/turn order.
+ *   <li>{@code currentBets} always contains an entry for every player in {@code playerOrder}.
+ *   <li>{@code holeCards} maps every player to a mutable list; if not present, it is created on
+ *       demand.
  * </ul>
  */
 public class GameState {
@@ -188,8 +184,7 @@ public class GameState {
     }
 
     /**
-     * Reset bets to 0 for ALL players (do not clear the map). Also resets table
-     * current bet to 0.
+     * Reset bets to 0 for ALL players (do not clear the map). Also resets table current bet to 0.
      */
     public void resetBets() {
         for (PlayerId id : playerOrder) {
@@ -232,8 +227,7 @@ public class GameState {
     // Cards
 
     /**
-     * Gives (overwrites) the two hole cards for the given player. Ensures stable
-     * list identity
+     * Gives (overwrites) the two hole cards for the given player. Ensures stable list identity
      * (important if other code holds references).
      */
     public void giveHoleCards(PlayerId playerId, Card c1, Card c2) {
@@ -293,14 +287,13 @@ public class GameState {
     /**
      * Starts a new hand by resetting the game state for the next round of poker.
      *
-     * <p>
-     * This:
+     * <p>This:
      *
      * <ul>
-     * <li>sets {@code phase=PREFLOP}
-     * <li>resets pot/bets/commitments
-     * <li>clears community + hole cards
-     * <li>creates &amp; shuffles a new deck
+     *   <li>sets {@code phase=PREFLOP}
+     *   <li>resets pot/bets/commitments
+     *   <li>clears community + hole cards
+     *   <li>creates &amp; shuffles a new deck
      * </ul>
      */
     public void startNewHand() {
@@ -336,4 +329,19 @@ public class GameState {
     public boolean isFolded(PlayerId playerId) {
         return getPlayer(playerId).isFolded();
     }
+
+    /**
+     * Counts the number of players who have not folded.
+     *
+     * @return The number of non-folded players
+     */
+    public int countNonFoldedPlayers() {
+        int count = 0;
+        for (Player p : players.values()) {
+            if (p != null && !p.isFolded()) {
+                count++;
+            }
+        }
+        return count;
+    }
 }