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..6a61cfd9 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
@@ -17,10 +17,14 @@
 import pp.battleship.message.server.StartBattleMessage;
 import pp.battleship.model.Battleship;
 import pp.battleship.model.IntPoint;
+import pp.battleship.model.Rotation;
+import pp.util.Position;
 
 import java.lang.System.Logger;
 import java.lang.System.Logger.Level;
+import java.lang.reflect.Array;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -142,10 +146,64 @@ public Player addPlayer(int id) {
     public void received(MapMessage msg, int from) {
         if (state != ServerState.SET_UP)
             LOGGER.log(Level.ERROR, "playerReady not allowed in {0}", state); //NON-NLS
+        else if (checkMap(msg, from))
+            LOGGER.log(Level.ERROR, "player submitted not allowed Map");
         else
             playerReady(getPlayerById(from), msg.getShips());
     }
 
+    /**
+     * Returns true if the map contains correct ship placement and is of the correct size
+     *
+     * @param msg the received MapMessage of the player
+     * @param from the ID of the Player
+     * @return a boolean based on if the transmitted map ist correct
+     */
+    private boolean checkMap(MapMessage msg, int from) {
+        int mapWidth = getPlayerById(from).getMap().getWidth();
+        int mapHeight = getPlayerById(from).getMap().getHeight();
+
+        if (mapHeight != 10 || mapWidth != 10)
+            return false;
+
+        // check if ship is out of bounds
+        for (int i = 0; i < msg.getShips().size(); i++){
+            Battleship battleship = msg.getShips().get(i);
+            if (battleship.getMaxX() >= mapWidth || battleship.getMinX() < 0 || battleship.getMaxY() >= mapHeight || battleship.getMinY() < 0) {
+                LOGGER.log(Level.ERROR, "Ship is out of bounds ({0})", battleship.toString());
+                return false;
+            }
+        }
+
+        // check if ships overlap
+        int[][] tempMap = new int[mapWidth][mapHeight];
+        for (int[] row : tempMap)
+            Arrays.fill(row, 0);
+        msg.getShips().forEach(s -> {
+            int deltaX = s.getMaxX()-s.getMinX();
+            int deltaY = s.getMaxY()-s.getMinY();
+            int lastX = s.getX();
+            int lastY = s.getY();
+            tempMap[lastX][lastY] += 1;
+            for (int i = 0; i < deltaX-1; i++)
+                for (int j = 0; j < deltaY-1; j++) {
+                    tempMap[lastX + (deltaX / Math.abs(deltaX))][lastY + (deltaY / Math.abs(deltaY))] += 1;
+                    lastX = lastX + (deltaX / Math.abs(deltaX));
+                    lastY = lastY + (deltaY / Math.abs(deltaY));
+                }
+        });
+        for (int[] row : tempMap){
+            for(int cell : row){
+                if (cell > 1){
+                    LOGGER.log(Level.ERROR, "There are multiple ships on one position");
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+
     /**
      * Handles the reception of a ShootMessage.
      *