The Chess Variant Pages

This page is written by the game's inventor, Stephen Tavener.

Quantum Chess

Quantum Chess first appeared in Variant Chess Magazine (issue 25, p106).


The normal rules of Chess apply, with the following change: a square is defined as unobserved if it is neither attacked nor defended. A piece on an unobserved quare may move to any empty unobserved square.


This is a pretty wild variant; pawns have the potential to jump straight to the 8th rank (and promote immediately), so keep your back row defended. The high mobility of the pieces in the mid/endgame can lead to Shogi-like mating sequences.

This 'user submitted' page is a collaboration between the posting user and the Chess Variant Pages. Registered contributors to the Chess Variant Pages have the ability to post their own works, subject to review and editing by the Chess Variant Pages Editorial Staff.

By Stephen Tavener.

Last revised by Fergus Duniho.

Web page created: 2021-04-14. Web page last updated: 2021-06-30

Revisions of MSquantum-chess