 The most common orthodox chess puzzle takes the form of checkmate in "n" moves.The puzzle positions are seldom similar to positions from actual play, and the challenge is not to find a winning move, but rather to find the (usually unique) move which forces checkmate as rapidly as possible.Heterodox chess problems involve conditions that are impossible with normal play, such as multiple kings or chess variants, while fairy chess problems employ pieces not used in orthodox chess, such as the amazon (a piece combining the powers of the queen and the knight).