diff --git a/OOP_2B1_Project/src/backend/KingCheck.java b/OOP_2B1_Project/src/backend/KingCheck.java
new file mode 100644
index 0000000..a42fe70
--- /dev/null
+++ b/OOP_2B1_Project/src/backend/KingCheck.java
@@ -0,0 +1,97 @@
+package backend;
+
+import java.util.ArrayList;
+
+public class KingCheck {
+	public ArrayList<ArrayList<Boolean>> getLegalMoves(Piece piece, ArrayList<ArrayList<Piece>> board) {
+	    ArrayList<ArrayList<Boolean>> rawMoves = piece.getPossibleMoves(board);
+
+	    ArrayList<ArrayList<Boolean>> legalMoves = new ArrayList<>();
+	    for (int y = 0; y < 8; y++) {
+	        ArrayList<Boolean> row = new ArrayList<>();
+	        for (int x = 0; x < 8; x++) {
+	            row.add(false);
+	        }
+	        legalMoves.add(row);
+	    }
+
+	    for (int y = 0; y < 8; y++) {
+	        for (int x = 0; x < 8; x++) {
+	            if (rawMoves.get(y).get(x)) {
+	                Move move = new Move(piece.getX(), piece.getY(), x, y);
+	                if (isMoveSafe(board, move, piece.isWhite())) {
+	                    legalMoves.get(y).set(x, true);
+	                }
+	            }
+	        }
+	    }
+
+	    return legalMoves;
+	}
+
+	private boolean isKingInCheck(ArrayList<ArrayList<Piece>> board, boolean isWhiteTurn) {
+	    int kingX = -1, kingY = -1;
+
+	    // Find the king
+	    for (ArrayList<Piece> row : board) {
+	        for (Piece p : row) {
+	            if (p != null && p.isWhite() == isWhiteTurn && p.getType() == PieceType.King) {
+	                kingX = p.getX();
+	                kingY = p.getY();
+	                break;
+	            }
+	        }
+	    }
+
+	    if (kingX == -1 || kingY == -1) {
+	        return true; // King not found, technically in check
+	    }
+
+	    // Check if any enemy piece can capture the king
+	    for (ArrayList<Piece> row : board) {
+	        for (Piece p : row) {
+	            if (p != null && p.isWhite() != isWhiteTurn) {
+	                ArrayList<ArrayList<Boolean>> moves = p.getPossibleMoves(board);
+	                if (moves.get(kingY).get(kingX)) {
+	                    return true; // King can be captured
+	                }
+	            }
+	        }
+	    }
+
+	    return false; // King is safe
+	}
+
+	private boolean isMoveSafe(ArrayList<ArrayList<Piece>> board, Move move, boolean isWhiteTurn) {
+	    ArrayList<ArrayList<Piece>> simulatedBoard = simulateMove(board, move);
+	    return !isKingInCheck(simulatedBoard, isWhiteTurn);
+	}
+
+	private ArrayList<ArrayList<Piece>> simulateMove(ArrayList<ArrayList<Piece>> board, Move move) {
+        ArrayList<ArrayList<Piece>> newBoard = deepCopyBoard(board);
+
+        Piece piece = newBoard.get(move.fromY).get(move.fromX);
+        newBoard.get(move.fromY).set(move.fromX, null);
+        piece.x = move.toX;
+        piece.y = move.toY;
+        newBoard.get(move.toY).set(move.toX, piece);
+
+        return newBoard;
+    }
+
+	private ArrayList<ArrayList<Piece>> deepCopyBoard(ArrayList<ArrayList<Piece>> original) {
+        ArrayList<ArrayList<Piece>> copy = new ArrayList<>();
+        for (ArrayList<Piece> row : original) {
+            ArrayList<Piece> newRow = new ArrayList<>();
+            for (Piece p : row) {
+                if (p != null) {
+                    newRow.add(PieceCreation.createPiece(p.getX(), p.getY(), p.getType(), p.isWhite()));
+                } else {
+                    newRow.add(null);
+                }
+            }
+            copy.add(newRow);
+        }
+        return copy;
+    }
+}