public boolean gameIsOver() {
		boolean foundWhiteKing = false;
		boolean foundBlackKing = false;
		for (int rank = 0; rank < this.board.length; rank++) {
			for (int file = 0; file < this.board[rank].length; file++) {
				if (this.board[rank][file] == Board.whiteKing) {
					foundWhiteKing = true;
				} else if (this.board[rank][file] == Board.blackKing) {
					foundBlackKing = true;
				}
			}
		}
		if (!foundBlackKing || !foundWhiteKing) {
			return true;
		}
		return false;
	}