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
Fifty-move rule discovered that certain endgame positions are winnable but require more than 50 moves (without a capture or a pawn move). The rule was therefore changed to allow certain exceptions in which 100 moves were allowed with particular material combinations. However, winnable positions that required even more moves were later discovered, and in 1992, FIDE abolished all such exceptions and reinstated the strict 50-move rule. The relevant part of the official FIDE laws of chess is rule 9.3: A claim does not have to be made at the first opportunity – it can be made any time when there have been