diff --git a/src/main/java/tictactoe/Client.java b/src/main/java/tictactoe/Client.java
index 95e7009..2dfb687 100644
--- a/src/main/java/tictactoe/Client.java
+++ b/src/main/java/tictactoe/Client.java
@@ -9,6 +9,7 @@
 import tictactoe.model.types.GameState;
 import tictactoe.model.types.PlayerType;
 import tictactoe.strategy.winning.ColumnWinningRule;
+import tictactoe.strategy.winning.DiagonalWinningRule;
 import tictactoe.strategy.winning.GameWinningRule;
 import tictactoe.strategy.winning.RowWinningRule;
 
@@ -35,6 +36,7 @@ public static void main(String[] args) throws Exception {
         List<GameWinningRule> rules = new ArrayList<>();
         rules.add(new RowWinningRule());
         rules.add(new ColumnWinningRule());
+        rules.add(new DiagonalWinningRule());
 
         Game game = gameController.startGame(players, rules, 3);
 
diff --git a/src/main/java/tictactoe/model/Game.java b/src/main/java/tictactoe/model/Game.java
index d931f6a..8b871ea 100644
--- a/src/main/java/tictactoe/model/Game.java
+++ b/src/main/java/tictactoe/model/Game.java
@@ -109,12 +109,17 @@ private boolean checkWinner(Board board, Move currMove) {
     }
 
     private boolean validateMove(Move currMove) {
-        if(currMove.getCell().getCellState().equals(CellState.FILLED)){
-            return false;
-        }
+        // if(currMove.getCell().getCellState().equals(CellState.FILLED)){
+        //     return false;
+        // }
 
+        // the above Condition is wrong since we are initializing the cellstate to empty for currMove
+        // We need to check the Board current row and col
         int row = currMove.getCell().getRow();
         int col = currMove.getCell().getCol();
+        if(board.getCells().get(row).get(col).cellState.equals(CellState.FILLED)) {
+            return false;
+        }
 
         if (row >= board.getSize()) {
             return false;
diff --git a/src/main/java/tictactoe/strategy/winning/DiagonalWinningRule.java b/src/main/java/tictactoe/strategy/winning/DiagonalWinningRule.java
index 8a734b3..a008671 100644
--- a/src/main/java/tictactoe/strategy/winning/DiagonalWinningRule.java
+++ b/src/main/java/tictactoe/strategy/winning/DiagonalWinningRule.java
@@ -2,10 +2,50 @@
 
 import tictactoe.model.Board;
 import tictactoe.model.Move;
+import tictactoe.model.Symbol;
+
+import java.util.HashMap;
+import java.util.Map;
 
 public class DiagonalWinningRule implements GameWinningRule{
+    private final Map<Symbol, Integer> diagCount = new HashMap<>();
+
+    private final Map<Symbol, Integer> antiDiagCount = new HashMap<>();
     @Override
     public boolean checkWinner(Board board, Move move) {
+        //S1: take the row and col and playerSymbol
+        //S2: check if the row and col comes under diag or antiDiag
+        //s3: check whether playerSymbol is existed other add the player symbol and count
+
+        int row = move.getCell().getRow();
+        int col = move.getCell().getCol();
+        Symbol playerSymbol = move.getPlayer().getSymbol();
+
+        //condition to check diagonal
+        if(row == col) {
+            if(!diagCount.containsKey(playerSymbol)) {
+                diagCount.put(playerSymbol, 0);
+            }
+            diagCount.put(playerSymbol, diagCount.get(playerSymbol)+1);
+
+            if(diagCount.get(playerSymbol).equals(board.getSize())) {
+                return true;
+            }
+        }
+
+
+        //condition to check antiDiagonal
+        if(row+col == board.getSize()-1) {
+            if(!antiDiagCount.containsKey(playerSymbol)) {
+                antiDiagCount.put(playerSymbol, 0);
+            }
+            antiDiagCount.put(playerSymbol, antiDiagCount.get(playerSymbol)+1);
+
+            if(antiDiagCount.get(playerSymbol).equals(board.getSize())) {
+                return true;
+            }
+        }
+
         return false;
         //HW
     }