Monochromatic chess is a

chess variant A chess variant is a game related to, derived from, or inspired by chess. Such variants can differ from chess in many different ways. "International" or "Western" chess itself is one of a family of games which have related origins and could be co ...

with unknown origin. The initial board position and all rules are the same as in regular chess, except that pieces that begin on a black square must always stay on a black square and pieces that begin on a white square must always stay on a white square. This would mean that

knights A knight is a person granted an honorary title of a knighthood by a head of state (including the pope) or representative for service to the monarch, the church, or the country, especially in a military capacity. The concept of a knighthood ...

can never move, but ''The Classified Encyclopedia of Chess Variants'' says that knights make a double jump. It has been suggested that a knight be replaced with a (3,1)-leaper (camel). If knights are allowed to move (or are captured, clearing the way),

castling Castling is a move in chess. It consists of moving the king (chess), king two squares toward a rook (chess), rook on the same and then moving the rook to the square that the king passed over. Castling is permitted only if neither the king ...

may become possible, but only on the . Under the rules, pawns can only move by (possibly ''

en passant In chess, ''en passant'' (, "in passing") describes the capture by a Pawn (chess), pawn of an enemy pawn on the same and an adjacent that has just made an initial two-square advance. This is a special case in the rules of chess. The capturi ...

'') or by advancing two squares for their first move. A

stalemate Stalemate is a situation in chess where the player whose turn it is to move is not in check and has no legal move. Stalemate results in a draw. During the endgame, stalemate is a resource that can enable the player with the inferior position ...

occurs if a player's king is not in check but the player nevertheless has no legal moves under the rules of the game. Similarly, a

checkmate Checkmate (often shortened to mate) is any game position in chess and other chess-like games in which a player's king is in check (threatened with ) and there is no possible escape. Checkmating the opponent wins the game. In chess, the king is ...

occurs if the king is placed in check and the king has no legal moves under the rules of the game. This means that certain board positions in regular chess which would not result in the end of the game can be checkmates or stalemates in monochromatic chess. For example, each player has one bishop for which it is possible to obtain checkmate with just this bishop and a king, while it is impossible with the other bishop along with the king, since only one bishop is capable of threatening the king of the opposing side. Because the two kings must occupy squares of different colours, they are allowed to be located next to each other. This variant is used mostly in

chess problems A chess problem, also called a chess composition, is a puzzle created by the composer using chess pieces on a chessboard, which presents the solver with a particular task. For instance, a position may be given with the instruction that White i ...

. Smullyan's example asks: What color is pawn g3 – white or black? Answer is black – with white pawns on d2 and f2, the white king can move from e1 only with castling kingside and then g1–h2–g3–... so the pawn on g3 cannot be white.

Bichromatic chess

In Bichromatic chess, the opposite restrictions apply. A piece on a white square must move to a black square and vice versa. Hence pawns cannot capture (or advance two squares) and bishops cannot move. Also, castling is impossible, and queens behave like rooks.

References

External links

* http://www.janko.at/Retros/Glossary/Monochromatic.htm {{Chess variants, state=collapsed Chess variants Fairy chess