Grant Acedrex


Grant Acedrex is a medieval chess variant dating back to the time of King Alfonso X of Castile. It appears in the Libro de los juegos of 1283.

Rules

The following rules are from the reconstruction given on the website of Jean-Louis Cazaux, based on work by him and Sonja Musser. The game is played on a 12×12 board.
Castling does not exist in Grant Acedrex. On its first move, however, a king may make a diagonal or orthogonal leap of two squares in addition to its normal moves.

Using dice

The game could be sped up by using eight-sided dice to dictate which piece could move that turn, ranking them in the order: king, aanca, rhinoceros, rook, lion, crocodile, giraffe, and pawn.

Computer players

The multi-variant Chess engines Fairy-Max and Postduif can play Grant Acedrex under the XBoard or WinBoard user interface.