The Chess Variant Pages

Chromopolis, a Colorful Chess Variant

Here's a little game that explores some of the consequences that a couple of quirky rules can have on the concepts of color and colorboundedness in a chess variant.


To capture the opponent's king.

Initial Setup:

At the start of the game, the board is setup as in the diagram above. The board is cylindrical; the A file is shown on each side only for symmetry-- both A files are the same. (And therefore, there are only 40 squares, not 44, an important point, this being an entry to the 40 square chess variant contest.)

Order of Play:

Players take turns moving pieces. White starts. It is not legal to move a piece to a square that is occupied by an unbound piece.


Each piece applies force to a number of nearby squares. (With the exception of the pawn and prelate, the pieces apply force to the same squares that they would be able to move to.)

At the end of a player's turn any piece with force from (at least) 2 of that player's pieces on it is captured. (Only pieces belonging to the opponent can be captured.)

Captured pieces are not removed from the game, but rather are bound to the square they reside on. Bound pieces cannot move, exert force or restrict other pieces from entering their squares. Effectively they only exist for the purpose of being unbound later.


Kings and knights (yes, that's a knight, not a penguin,) move just as in standard chess and apply force to the same squares that they could (if the board were otherwise empty,) move to. Pawns move one square forward, (no first move exception,) and apply force one square diagonally forward, (to the same squares where a normal chess pawn could capture.)

The Advocate:

Moves and applies force as a ferz or dabaaba (Betza notation: FD)

The Prelate:

Moves as a ferz (red arrows), applies force as a knight and wazir (green crosses.)

Unbinding pieces:

A Bound piece is unbound, (i.e., it becomes a normal piece,) at the end of its owner's turn, after any opposing pieces are captured, if it meets the following requirements:
  • There is no unbound piece on the same square.
  • There are at least two units of forced placed on its square by other of its owners piece.
  • There is no force on its square from pieces belonging to the opponent.
If there is more than one bound piece on the same square when the unbinding requirements are met, their owner must choose one (and only one,) to be unbound. Force from pieces that were just unbound does not count toward binding or unbinding any other pieces that turn.


Upon reaching the last row, a pawn can promote to a knight, advocate, or prelate. Note that pawns cannot stray from their initial files so there is no possibility of a pawn getting stuck in the A file. Promotion occurs before pieces are captured and unbound.

Some thoughts:

The capture mechanism is inspired by rythmomachy, where captures are also instantaneous by threat, and requiring cooperation from more than one piece. I used something similar in enantiomerfolk. The possiblility of a dynamic like that between the advocates and prelates occured to me pretty quickly. Notice that, (if the squares were black and white,) a black advocate on a black square would dominate (be able to attack but not be attacked by,) a white prelate on a black square, which would dominate a black advocate on a white square, which would dominate a white prelate on a white square....

But the squares are not strictly black and white which makes the situation more interesting. The cylindrical board with an odd number of files makes it possible to change colors. (I know that I've seen another game with this feature on the chess variant pages, but I cannot find it now.) I felt that this would be useful for my small chess variant with advocates and prelates because having numerous colorbound pieces would greatly decrease the number of positions that could be achieved, and small variants are limited enought to start out with.

The unbinding mechanism was added because I thought that cooperative captures would otherwise make too many games stalemated because of insufficient material. I could have just added drops, but that's been done.

Alexandre Owen Muniz

Written by Alexandre Owen Muniz.
This is an entry in the competition to design a chess variant on a board with 40 squares.
WWW page created: January 17, 1999.