In the game of chess, perpetual check is a situation in which one player can a draw by an unending series of checks. This typically arises when the player who is checking cannot deliver checkmate, and failing to continue the series of checks gives the opponent at least a chance to win. A draw by perpetual check is no longer one of the rules of chess; however, such a situation will eventually result in a draw by either threefold repetition or the fifty-move rule. Players usually agree to a draw long before that, however. .