Monochromatic chess d2 and f2, the white king can move from e1 only with castling and then g1–h2–g3–... so the pawn on g3 cannot be white. 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 and "en passant" are impossible, and queens behave like rooks. Monochromatic chess Monochromatic chess is a chess variant with unknown origin. The initial board position and all rules are the same as in regular chess, except that pieces that begin
Touch-move rule the player is about to touch a piece on the board, typically to centralise it on its square, without the intent of making a move with it. Although this French term is customary, it is not obligatory; other similar indications may be used. A player may adjust a piece in this way only when it is his turn to move. There have been occasions in chess history when a player has uttered "j’adoube" after making a losing move in order to retract it, thus attempting to avoid the touch-move rule. Such behaviour is regarded as cheating (see cheating in chess).