The Joker is a piece, infrequently used in fairy chess problems, invented by the famous chess problem composer T. R. Dawson. The Jester from Jester Chess is based upon this piece.
MovementThe Joker can move like the last piece moved by the opponent. E.g., when the opponent has played with a knight, the player can make a knight-move with the Joker. (No distinction is made for moves that take a piece or that do not take.) When moving like a king, the Joker is not hindered by check: it is never royal.
DetailsEven in the mating position, the joker can change its type of movement. I do not know whether a joker can promote to another piece when it mimics a pawn move.
This is an item in the Piececlopedia: an overview of different (fairy) chess pieces.
Written by Hans Bodlaender.
WWW page created: June 3, 1999.