Pin (chess) Pin (chess) In chess, a pin is a situation brought on by an attacking piece in which a defending piece cannot move without exposing a more valuable defending piece on its other side to capture by the attacking piece. Moving the attacking piece to bring on the pin is called pinning; the defending piece so restricted is described as pinned. Only pieces that can move an indefinite number of squares in a horizontal, vertical, or diagonal line (i.e. bishops, rooks, and queens) can pin. Kings, knights, and pawns cannot pin. Any piece can be pinned except the king, since the
Fairy chess piece Thus, the ferz is now considered a non-standard chess piece. Chess enthusiasts still often like to try variations of the rules and in the way pieces move. Pieces which move differently from today's standard rules are called "variant" or "fairy" chess pieces. Fairy chess pieces usually fall into one of three classes, although some are hybrids. Compound pieces combine the movement powers of two or more different pieces. An ("m","n")-leaper is a piece that moves by a fixed type of vector between its starting and destination squares. One of the coordinates of the vector 'start square – arrival square' must