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The Chess Variant Pages

This page is written by the game's inventor, Derick Peterson.

Derick Peterson's Cobra Chess


In January 1998, Derick Peterson sent us the following email:

I have enjoyed reading about chess variants at your web site. Here is a little (well, actually a Large) chess variant I dreamed up which uses a very unusual and fun piece: The Cobra.

This variant was invented on 9/6/97.


10 by 10 square checkerboard.


Castling is not permitted.

Double Pawn Advances And En Passant Captures

As in FIDE Chess, these are allowed.

Pawn Promotion

Pawns may promote upon reaching the 10th rank, but they may only promote to pieces captured by the enemy. If all of a players 10 pieces are on the board, then any of his pawns on the 9th rank are forbidden to advance to the 10th rank until he loses a piece, though they can still check the enemy King.

The 20 Pieces And Their Movement

10 Pawns
2 Bishops
1 Knight
1 Rook
1 Queen
1 King
1 Vizir
1 War Machine
1 Duke
1 Cobra


As the Queen combines the powers of the Bishop and the Rook, the Vizir (a.k.a. Cardinal, Pegasus, Archbishop, Centaur) combines the powers of the Bishop and the Knight. Thus, this diagonal piece can change colors via its Knight move. The move of this piece dates back to at least 1617 (Pietro Carrera, a priest, chess player, and author from Militello, Sicily), and the name used here comes from "Turkish Great Chess" (1797). The Vizir is thought to be worth about a pawn less than the Queen.

War Machine

As the Queen combines the powers of the Rook and the Bishop, the War Machine (a.k.a. Marshall, Chancellor, Minister, Champion) combines the powers of the Rook and the Knight. The move of this piece dates back to at least 1617 (Pietro Carrera, a priest, chess player, and author from Militello, Sicily), and the name used here comes from "Turkish Great Chess" (1797). The War Machine is equal in power to the Queen.


The Duke combines the moving and capturing powers of the Knight and the King, except that, unlike the King, threats to the Duke need not be parried, and the game is not over until his King is checkmated. Thus, the Duke makes a formidable guard for the King, and it has offensive potential as well. I estimate that the Duke is about equal in power to a Rook. As far as I know, this is a new piece, but I could certainly be ignorant of its earlier existence. In Turkish Great Chess, however, the Giraffe combined the powers of the Knight and the Queen. My guess is that the Giraffe did not survive to the present since it is simply too powerful a piece to make for a truly interesting game of strategy; for example, the Giraffe can easily checkmate a King with no help from supporting pieces, and no piece can threaten a Giraffe without putting itself within capturing range of the Giraffe.


The Cobra moves on straight lines any number of points, slithering between (i.e. jumping) any number of friendly (but no enemy) pieces, and comes to rest on intersections of the grid lines. He is considered to occupy all 4 squares about the intersection, and thus enemy pieces may capture him by moving to any of these 4 squares.

The Cobra may capture up to 2 enemy pieces simultaneously since if they lie along the same rank or file he may move to the intersection between them, capturing them both.

The Cobra must stop upon reaching the *first* enemy piece in its rook-like path when capturing, preventing the capture of enemy pieces behind that first piece.

Note that the Cobra may only move to an intersection if its surrounding 4 squares are, after possibly capturing 1 or 2 enemy pieces, unoccupied.

I estimate that the Cobra is about equal in power to the Queen.

Additional Notation

Duke (D), War Machine (W), Vizir (V), Cobra (C).


Here is the set-up for White. Black's set-up is the reflection. 1st rank: Rook on the leftmost file, Cobra on the rightmost files. 2nd rank: from left to right, the pieces are DBNQKWBVC. 3rd rank: All 10 Pawns begin on the 3rd rank.


All pawns are initially protected, they guard all pieces behind them from attack, and they restrict the movement of the Bishops, Rook, Queen, and King. Pieces are organized so as to roughly balance the power of the Queen's and King's side as well as the number of jumpers, diagonal sliders, and rank-file sliders. The King is flanked by the 2 strongest pieces.

Written by Derick Peterson. HTML conversion and diagram by David Howe.
WWW page created: January 26, 1998. Last modified: January 29, 1998.