A variation of Chess involving a change in the form of the board, the rules of play, or the pieces used. For example, the normal rules of chess can be used but with a cylindrical or Möbius Strip connection of the edges.
See also Chess
References
Kraitchik, M. ``Fairy Chess.'' §12.2 in Mathematical Recreations. New York: W. W. Norton,
pp. 276-279, 1942.