The Chess Variant Pages

Evolution Chess

By Harvey Patterson

Introduction

In Evolution Chess, all the normal rules of Western Chess apply except for the possibility of evolution through promotion capturing. Pieces are seen as a combination of their abilities: the ability to move like a Knight, Bishop or Rook. Whenever a piece, not a Pawn, other than the King captures another piece it adds any additional powers that piece had into its DNA and promotes to a hybrid piece. For example: a Rook that captures a Bishop gains the ability to move diagonally and evolves into a Queen.

Pieces

Simple pieces are the Knight, Bishop and Rook, compound pieces are the Cardinal [Bishop+Knight], Marshall [Rook+Knight], Queen [Rook+Bishop] and Amazon [Rook+Bishop+Knight]. Since the Amazon possesses all three powers any piece that captures an Amazon becomes an Amazon. All other captures that cause evolution are listed below.
Knight + Bishop/Cardinal = Cardinal
Knight + Rook/Marshall = Marshall
Knight + Queen = Amazon

Bishop + Knight/Cadinal = Cardinal
Bishop + Rook/Queen = Queen
Bishop + Marshall = Amazon

Rook + Knight/Marshall = Marshall
Rook + Bishop/Queen = Queen
Rook + Cardinal = Amazon

Cardinal + Rook/Marshall/Queen = Amazon

Marshall + Bishop/Cardinal/Queen = Amazon

Queen + Knight/Cardinal/Marshall = Amazon
Pawns are seen as underdeveloped species which can adapt or evolve through promotion into any of the simple pieces: Knight, Bishop or Rook. Hybridization can only be achieved through promotion capturing, there are no shortcuts in evolution. Thus, a Pawn does not absorb the movement abilities of a piece it captures.

Strategy

Evolution Chess is a defensive battle with deep tactics. Capturing can actually kill you if a piece with different powers recaptures and promotes. Pieces should be protected by at least one piece at all times because, if captured, you can not only lose the piece for nothing but promote one of your opponent's pieces.

When promoting Pawns carefully consider your evolutionary options. The correct choice may be a matter of what pieces are left in the gene pool. It may be preferable to promote to a piece that has different abilites in its genes than the pieces your opponent has left in the hope of evolving further through promotion capturing.

Like Chess, ultimately you want to control space, win material and find tactics that lead to checkmate. Moves that increase your options and decrease your opponent's options are generally best.

Computer Play

I have written an implementation of Evolution Chess for Zillions of Games. You can download it here:


Editorial Note: Evolution Chess is similar to the old game of Absorption Chess, but differs in the treatment of Kings and Pawns. It is even more similar to the variant of Absorption Chess implemented in this applet by Ed Friedlander, but differs in Pawn behavior and promotion. These differences, however, are sufficient to produce a very different game. Evolution Chess should not suffer as much from the Absorption Chess problem that exchanges are often a big win for the last player to capture, since an exchange that ends in a Pawn capture doesn't result in a gain of material via absorption.
Written by Harvey Patterson.
WWW page created: May 23rd, 2003.