My goal in setting up "back to back" chess was to utilize the 100-square variant to fundamentally reorient the players' opening positions. Rather than creating new pieces, I chose to use only the standard chess pieces with minimal variation in movement rules. Only the pawn has a change in its movement rules, allowing lateral movement, though the opening positions for all pieces are changed.
-- The chess pieces all have standard movement and capturing capabilities with the exception of pawns.
-- Pawns may move laterally as well as forward, two squares to one side or another in the pawn's first move and one square thereafter. Although a Pawn may move sideways, it may still capture only in the two forward directions.
-- A Pawn may capture an enemy Pawn by en passant on the move immediately after an enemy Pawn's initial two space move takes it over a space the Pawn could have captured it at. In capturing en passant, the Pawn moves to this space, capturing the enemy Pawn in passing. This is essentially how en passant is done in regular Chess, but this more general description covers en passant for Pawns that can move sideways as well as forwards.
-- The game is played on a one hundred square board. The eight squares in the center of the board, rows four and five of columns F, G, H, I, are separated by an impassable barrier and cannot be crossed over by any piece; Knights may not pass over this barrier in their jump. Due to the border and the unusual setup of the pieces, some other details have to be noted.
-- The Knight moves two spaces orthogonally, then moves one more space at a right angle. If any part of this path would take a Knight over the border, it may not make the move.
-- Castling is done as it is in regular Chess with the understanding that the orthodox chess setup is curved into a U shape. Kingside castling is straightforward: the King moves forward two spaces (H1-H3), and the Rook passes over the King (H4-H2). Queenside Castling appears more ambiguous because of the different ranks/files involved. The King moves over one and up one (H1-G1-G2), and the Rook passes over the King (G4-G1).
-- All other chess rules remain the same. The promotion ranks are rows one and eight.
The "Back to Back chess" board is shown
below. Players may copy enlarge this map to play the game.
Starting positions for the pieces in
Back-toBack chess are shown below
(Columns F, G, H, I; and Rows 1-8 are shown):
"Back to Back Chess" for 100-square board: Copyright 2000 by Paul Kreutzer, paul_(email removed contact us for address) mail.com
Back-to-Back Chess has now been implemented for Zillions of Games. If you have Zillions of Games, you may download the following zip file and play Back-to-Back Chess on your PC.