This is a complete re-do of Hyperchess. It has been played, and playtested, enough to be able to make small but significant changes to the rules to greatly improve the game.
- The minimum amount of material for a forced mate against a bare king, a pair of bishops, is demonstrated.
- The knight move is illustrated.
- A sample game is included.
- The Pawn Protection rule is dropped.
- The Held King rule is expanded.
- A discussion of various aspects of higher dimensional chess design is included.
This game should really be called Modern Sphinx Chess, as it is effectively an updated version of VR Parton's Sphinx Chess. But it was independently designed and named, and it deserves its own bad name, even though it acknowledges Parton was there first. This game just goes farther, and fills in missing territory in Sphinx Chess.
There are a number of people to acknowledge, without whose help I would not have been able to do all this.
Larry Smith was the one who introduced me to Sphinx Chess in a comment he made about the posting, and he was also kind enough to make a zillions implementation under the name "Hyperchess".
Dennis Joyce and Abdul-Rahman Sibahi playtested it with me. Further playtesting to determine the minimum material for a forced mate was conducted by Ben Reiniger and the author in 2010.
Both Jeremy Good and Abdul-Rahman Sibahi made presets for this game, found at play.chessvariants.org.
Abdul-Rahman Sibahi proposed the extension of the held king rule to occupying the same little squares. This aids significantly in mating.
The updated rules are found: http://chessvariants.wikidot.com/hype:a-study-in-bs
The original rules are found: http://www.chessvariants.org/3d.dir/hyperchess.html
A zillions version si found here: http://zillionsofgames.com/zilligames/pics/submissions/game1033_scr_Hyperchess.gif