Object: Checkmate the opponent's King. Pawns do not capture en passant and there is no castling. Otherwise rules are as in Chess, with the movements of pieces adapted to the new board. Pawns do promote when they reach a space originally occupied by an opposing non-pawn.
 
Circular Chess was invented in 1983 by Dave Reynolds, the founder of The Circular Chess Society. Reynolds was inspired by a picture in a book from 1905 showing an 11th-century circular chess board (probably Byzantine Chess or a descendant thereof).