Pocket mutation chess

Pocket mutation chess is a chess variant invented by Mike Nelson in 2003. [ [http://www.chessvariants.org/large.dir/pocketmutation.html Pocket mutation chess] by Mike Nelson] In this game a player can take a piece from the board and put it into a "pocket". The piece in the pocket can be put back on the board later. When placing the piece into the pocket the player can "mutate" the piece, i.e. change it to the different piece.

Rules

Starting position in this game is the same as in standard chess. Players make moves as in standard chess. Instead of moving a player can take one of their own pieces from the board and put it into the pocket, provided that the pocket is empty. If the piece is placed into the pocket from the last rank, it gets promoted to the piece of the higher class. Otherwise the player has an option to mutate the piece into a different piece of the same class. White cannot use the pocket on the first move. King cannot be placed into the pocket.

A piece in the pocket can be dropped later on any empty position on the board, except the last rank. A pawn can make only single steps from the first rank, but can do double steps from the second one, even if dropped there or moved from the first rank. The en passant rule applies as in standard chess. Pawns that reach the last rank do not get promoted immediately. Instead, they can be placed into the pocket and promoted to the piece of the higher class.

There is no castling in this chess variant. The game is declared a draw if no capture or promotion was made for 50 consecutive moves.

Classes of the pieces

Besides usual pieces there are several fairy chess pieces in this game. All pieces are divided into the following classes. All pieces from the same class are of presumably the same (or close) value.

Chess diagram|=
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8 | | | | |xx| | | |= 7 | | | | | | | | |= 6 | | | |xx| | | | |= 5 | | | | | | | |xx|= 4 |xx| |xx| | |xx| | |= 3 | | | |xx| | | | |= 2 | |sl| | | | | | |= 1 | | | |xx| | | | |= a b c d e f g h

Nightrider makes any number of knight moves in the same direction.

References