All pieces move as they do in standard chess. Pawns promote on the farthest square of whatever file they are on. Castling is performed by king swapping places with a rook. The king mustn't be in check. On this board N + N can checkmate, with the aid of the K.

Troitzky Chess was inspired by a remark of the end-game study analyst Troitzky that checkmate by two knights is possible if you add two extra squares to the board behind each back rank. The included setup was suggested by G. Jelliss.