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

Quantum Chess

Quantum Chess first appeared in Variant Chess Magazine (issue 25, p106) in 1997.


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.

Editorial Note on the History of the Name Quantum Chess

The name Quantum Chess has been a popular one. Here are some other games with the same name.

Douglas A Engel (1968)

Engel's 1968 game is described by David Pritchard in The Encylopedia of Chess Variants. It was played on 6x8 board with 8 pieces were side. Pritchard does not provide a setup diagram, a description of the pieces, or a description of the rules. He very vaguely says, "Movement is expressed by equations of motion based on certain integral values of x and y."

Quantum Development Inc.

In his "Isolated Pawns" column for Variant Chess 17, David Pritchard described a set of 4 commerical games called Quantum Chess I, II, III and IV. No one is credited with the invention of these games, but are associated with Quantum Development Inc. of Carson, Nevada. We once had a link page to a now defunct site describing this game at Judging by the use of the same graphics and logo, the now defunct site was used to describe Quantum Chess I.

Stephen Tavener

This is the version this page is mainly on. Pritchard writes "Stephen Tavener was unimpressed by any of the versions of Quantum Chess (presumably the game I reviewed in VC17)."

Quantum Realm Games

This version is playable on Steam, and we have a link page to its website at

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