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This page is written by the game's inventor, David Jagger.

Keltic Chess

By D.T. Jagger

Keltic Chess is essentially orthodox western chess but on a modified (cross-shaped) board, with an extra pawn per player, and modified pawn and bishop moves.


The squared board (illustrated) consists of a symmetrically-shaped overlapping composite of a 5x5 central area, a 3x7 vertical rectangle and a 3x9 horizontal rectangle, which gives 43 square cells in all, checked dark(20) and light(23) with the central cell light.

Keltic Chess setup

All 32 orthochess tokens are used plus an extra pawn for each side. The start position (illustrated) is as follows:

B d7, K e7, B f7,
R c6, N d6, Q e6, N f6, R g6,
P a5, P b5, P c5, P d5, P e5, P f5, P g5, P h5, P i5.

P a3, P b3, P c3, P d3, P e3, P f3, P g3, P h3, P i3,
R c2, N d2, Q e2, N f2, R g2,
B d1, K e1, B f1.


*1* Object

The object is 'checkmate' as in orthodox western chess (orthochess).

*2* Moves

Pawns (P) can move only one space on any go. They normally move one space straight forward, but if impeded from straight forward movement by the board edge or by another token (of either side), they may move one space sideways into an empty square (irrespective of whether a diagonal capture was available to them). They capture one space forward diagonally only, and never diagonally backwards.

There is no 'en passant'.

Knights (N) move as in orthodox chess.

Bishops (B) move as either bishop or knight in orthochess. (Without this additional power of the knight move, all bishops would be colourbound on the light squares.) When they move as a knight they can also leap other tokens as a knight, but they cannot leap when moved as an orthodox bishop.

Rooks (R) move as in orthochess.

Queens (Q) move as in orthochess. Note that unlike the 'Keltic' bishops, they do not have additional knightly powers.

Kings (K) move as in orthochess, except that there is no 'castling'.

*3* Promotion

Pawns promote on any of the 3 squares of the final rank to any piece (of their own colour) except king.

*4* All other rules are as for orthochess.

That's it!

Design background, thoughts and influences

This game of 'Keltic Chess' was inspired by the Chessvariants 43-space competition of 2003 and was created in March 2003.

The game is named after the shape of the board which somewhat resembles a Celtic Cross. As there is a generic entry for the ancient 'Celtic Chess' family (aka 'Fidchell' or 'Gwyddbwyll') in Pritchard's 'Encyclopedia of Chess Variants', I have varied the name to 'Keltic'.

Naturally the main influence on the game was orthodox western chess. There are several variants which already make use of the popular bishop-knight combination piece. The pawn's exceptional sideways move (when impeded) was suggested by the shape of the board itself, and it seemed natural to extend that move option to situations where a pawn was impeded by a token too. There are likely to be other variants out there which make use of such a move. Having designed the game I flicked through Pritchard to see if there was anything similar - the nearest I could find was 'Balbo's Game' (1974), which, though, has fewer pawns per side (7), a different initial setup (with central colourbound bishops), a rather different board (stepped, with 70 squares), and (from the brief description) no unorthodox moves.

Experimenting with a new game, one is always in the lap of the gods, and when a game's start position would seem to be so constricted (with a tokens to cells ratio of 34:43 and with only a single rank separating the opposed forces), one prays that the game won't throw up any too easily evident forced mate. If there is one, I am far from having spotted it.

The board shape came to me after I had been fiddling around with interwoven designs - I saw a suitable 43 cell pattern that looked challenging and different. The initial layout (and even the exceptional moves) immediately suggested themselves and it was then just a matter of playtesting the game to check for any obvious flaws.

The board's central cell ensured against symmetrical play. The pawn's exceptional move helped prevent blockage mid-board or stymied play, and offered tactical variety. The bishop's dual move contributed necessary protection to the back lines prior to development. 'Keltic' battle is close-quartered and fierce. Engagement is immediate and grappling relentless.

Of definite appeal was the apparent lack of advantage to white whose first move must be into the thick of things, usually offering an exchange of pawns. Barring the discovery of some computer-generated mate in 7, the game appears to offer good possibilities for both sides.

The initial constriction (which was the main challenge), though certainly felt, does not appear to be fatal. The preliminary bout of close wrestling helps define what is distinctive about the game. Although there are only 180 positions after move 1 (really only about 90 if the bilateral symmetry is taken into account) compared to the 400 of orthodox chess, the game does tend to open up, chiefly as a result of the greater move options available to pawn and bishop. A single pawn advantage can decide a game. The board shape presents its own mating possibilities. There is theoretical mate with king and 2 pawns, or pawn and knight, or 2 knights, or 1 bishop, or 1 rook, or 1 queen.

I had worried that the left and right 'extremities' of the board would be under-utilised and that pawns particularly might linger there unused. Game play proves this not to be the case, and side pawns do promote. Those deeper corners can also provide harbour for a hard-beset king.

The power of the pieces (though variable during a game and always difficult to quantify) is rather different from orthochess. My own valuations (for what they're worth) are:- Q9, B7, R5, N4, P2.

The game is like a death-grip struggle. Cascading blades clash in an ancient mead. A few stubborn heroes emerge to stand or fall beside their king.

This is my second published game. I hope you enjoy it!

Written by D.T. Jagger.
WWW page created: April 27, 2003.