Crooked Board Chess

Since the invention of the Crooked Bishop there have been several variants devised for Crooked pieces, including my own Herichess. It occurred to me to also consider a whole board that is crooked, and this is what I have devised here - although its linepieces are entirely straight.

Since first posting this page I have had my attention to two earlier variants that could be described as "Crooked Board Chess". Romanchecko's Chess has a similar level of crookedness, while Zigzag Chess could be seen as the possibly inadvertent "Really Crooked Chess" in George Duke's comment below.

I decided not to break up the board so much as to require the use of, for example, Crooked Rooks, but to stick to 4x4 supersquares - a terminology inherited from Intrusive Squares which deals with concavities the same way. I also decided to arrange it so as to minimise shortening and lengthening of Pawn treks, ruling out having some files of length 4. I eventually settled on having all files of length 8 but some ranks of width 4.

Arrangement of pieces is heavily influenced by John Groeneman's Half Chess, which has 4 files throughout and no Pawns, via my own Fivequarters, some versions of which have some or all Pawns added back in.

Setup

Pieces

Pieces are as in FIDE Chess.

Rules

The one-foot-in-the-grave rule applies. Thus Kings and Knights cannot cross between ranks 4 and 5, or 8 and 9, and also between files d and e, in the same move. Queens and Bishops cannot do so in the same step of a move, but they can cross one and then the other as parts of a longer move.

Pawns starting at the back of their file may make a double-step noncapturing move from either that cell or the next, and may immediately be captured En Passant by enemy Pawns. Pawns starting in front of their allies have no double-step move. Unpromoted Pawns are barred from capturing from file d to file e and vice versa. Promotion is required on reaching the end of any file.

Check, Checkmate, and Stalemate are standard.

Last revised by H. G. Muller.