Check out Glinski's Hexagonal Chess, our featured variant for May, 2024.

This page is written by the game's inventor, Jean-Louis Cazaux.


Jean-Louis CAZAUX (April 1999)

In honor of Edward Jackman who invented WWII Chess, opposing Shogi against FIDE Chess and called it " a really silly idea ". This is an even more silly idea :

Planet Mars is populated, now that’s for sure. We must conquer it, so a Human army is sent there. FIDE guys are not strong enough, then a decimal team is selected for the big pride of colonizing this new land..

This game celebrates the War Of The World, as described by H.G.Wells : it is Chess (reinforced) against Jetan.

A Zillions-of-game file has been designed. Play it and enjoy a very fun game.



The board represents the open land of Barsoom (i.e. Mars for Them). It has 10 x 10 square. One player has the 20 pieces found in Jetan. The other one has the 22 pieces used for Shako.


Rules of Shako and Jetan are maintained as much as possible. See their dedicated entry for details.

Shako player wins if he can checkmate either the Martian Chief or the Princess.

Jetan player wins if he can checkmate the Human King.

Remark : the Chief is a very strong piece, it is why is assumed royal here. Even with that, the game is tough for Humans. If your invasion of Barsoom fails, you can select another army and try again.


Other decimal chess games can be tried with the Zillions-Of-Game file made available :

Grand Chess versus Jetan :

Grand Chess is the invention of Christian Freeling (1984), introducing Marshall and Cardinal. It has a lot of predecessors among them is P.Carrera (1617) and the World Chess Champion J.R.Capablanca (1920). However, Grand Chess seems superior thanks to a very nice initial arrangement


Decimal Omega versus Jetan :

Omega Chess has been recently invented by Daniel Mac Donald and endorsed by some American Grand Masters. The original game uses a special 10x10 board with 4 extra cases at the corner. Decimal Omega is a proposed variant by J.L.Cazaux re-arranging the team on a regular 10x10.


Xhess versus Jetan :

Xhess has been invented in 1999 by David Howe as an example of a Large Chess Variant for the contest he organized on Hans Bodlaender's CV Pages. Although, not a competing game, it has very nice features and would have been a serious competitor.


Turkish Chess versus Jetan :

Probably more Indians than Turkish but those countries were probably very far for Gollon who mixed all them in his book. Anyway, it is a straight way to introduce the Amazon on the board. Probably the easiest way to colonize Mars !

Written by Jean-Louis Cazaux, Toulouse, France.

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WWW page created: August 4, 1999. Last modified: September 13, 1999.