diff --git a/Projekte/.run/Projekte [test].run.xml b/Projekte/.run/Projekte [test].run.xml
index 4a9bc669..6170aefe 100644
--- a/Projekte/.run/Projekte [test].run.xml	
+++ b/Projekte/.run/Projekte [test].run.xml	
@@ -2,7 +2,7 @@
   <configuration default="false" name="Projekte [test]" type="GradleRunConfiguration" factoryName="Gradle">
     <ExternalSystemSettings>
       <option name="executionName" />
-      <option name="externalProjectPath" value="$PROJECT_DIR$" />
+      <option name="externalProjectPath" value="$PROJECT_DIR$/Projekte" />
       <option name="externalSystemIdString" value="GRADLE" />
       <option name="scriptParameters" value="--continue" />
       <option name="taskDescriptions">
diff --git a/Projekte/battleship/model/src/main/java/pp/battleship/game/server/ServerGameLogic.java b/Projekte/battleship/model/src/main/java/pp/battleship/game/server/ServerGameLogic.java
index a5987fa1..f761a5a8 100644
--- a/Projekte/battleship/model/src/main/java/pp/battleship/game/server/ServerGameLogic.java
+++ b/Projekte/battleship/model/src/main/java/pp/battleship/game/server/ServerGameLogic.java
@@ -140,10 +140,20 @@ public Player addPlayer(int id) {
      */
     @Override
     public void received(MapMessage msg, int from) {
+        Player player = getPlayerById(from);
+        List<Battleship> ships = msg.getShips();
+
         if (state != ServerState.SET_UP)
             LOGGER.log(Level.ERROR, "playerReady not allowed in {0}", state); //NON-NLS
-        else
-            playerReady(getPlayerById(from), msg.getShips());
+        else {
+            if (!checkShips(player, ships)) {
+                LOGGER.log(Level.ERROR, "{0} submited an illegal map", player); //NON-NLS
+                send(player, new GameDetails(config));
+            }
+            else {
+                playerReady(player, msg.getShips());
+            }
+        }
     }
 
     /**
@@ -173,6 +183,7 @@ void playerReady(Player player, List<Battleship> ships) {
             return;
         }
         ships.forEach(player.getMap()::add);
+
         if (readyPlayers.size() == 2) {
             for (Player p : players)
                 send(p, new StartBattleMessage(p == activePlayer));
@@ -180,6 +191,29 @@ void playerReady(Player player, List<Battleship> ships) {
         }
     }
 
+    /**
+     * Checks if all ships are placed correctly.
+     *
+     * @param player the player who is ready
+     * @param ships  the list of ships placed by the player
+     * @return true if all ships are placed correctly, false otherwise
+     */
+    private boolean checkShips(Player player, List<Battleship> ships) {
+        for(Battleship ship : ships) {
+            for(Battleship other : ships) {
+                if(ship.collidesWith(other)) {
+                    return false;
+                }
+            }
+
+            if(!player.getMap().isValid(ship)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
     /**
      * Handles the shooting action by the player.
      *
diff --git a/Projekte/battleship/model/src/main/java/pp/battleship/model/dto/ShipMapDTO.java b/Projekte/battleship/model/src/main/java/pp/battleship/model/dto/ShipMapDTO.java
index 9d53146c..582d119f 100644
--- a/Projekte/battleship/model/src/main/java/pp/battleship/model/dto/ShipMapDTO.java
+++ b/Projekte/battleship/model/src/main/java/pp/battleship/model/dto/ShipMapDTO.java
@@ -53,7 +53,7 @@ public ShipMapDTO(ShipMap map) {
      * Checks if the current ship map fits the game details provided.
      *
      * @param details the game details to be matched against
-     * @return true if the ship map fits the game details, false otherwise
+     * @return true if the ship map fits the game details and all ships have a valid position, false otherwise
      */
     public boolean fits(GameDetails details) {
         if (width != details.getWidth() || height != details.getHeight())
@@ -61,6 +61,14 @@ public boolean fits(GameDetails details) {
         int numShips = details.getShipNums().values().stream().mapToInt(Integer::intValue).sum();
         if (numShips != ships.size())
             return false;
+
+        ShipMap map = new ShipMap(width, height, null);
+        for(Battleship ship : map.getShips().toList()) {
+            if(!map.isValid(ship)) {
+                return false;
+            }
+        }
+
         for (var e : details.getShipNums().entrySet()) {
             final int shipLength = e.getKey();
             final int requiredNum = e.getValue();