So i played cylindrical chess with Lionel tonite. Yes that's exactly what it sounds like, chess played on a cylinder. So a piece can go out the left or right side and come out on the other. It makes openings bizarre because moving pawn to g3 suddenly pins blacks d pawn with the bishop, while moving the c pawn suddenly pins the f pawn with the queen. Certain affects of this rule change are obvious: bishops are much more powerful than before (in particular more powerful than knights), castling is less obviously good, rooks can connect easily, etc. But all this is relatively tame compared to the end game. Suddenly a rook and a king no longer checkmate. Furthermore getting perpetual check is much easier. Anyway its a fun twist on an good old game.