Haaner Chess: Any square left can’t be neither occupied nor crossed.

Messigny Chess: Instead of a normal move either side may interchange the positions of any pair of like pieces (including kings) of different coulours. Such an interchange may bit immediately be reversed by the other side.

Bichrome Chess: All moves, captures and checks must be made between squares of opposite colors. Thus, all Bishop moves, short castling or long castling are illegal. En passant captures are not possible. The Pawn promotions are possible only with non-capturing-moves.