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This page is written by the game's inventor, Charles Gilman.

Double Cross Besiege

The Besiege Chess family of variants and my own offshoot Quadruple Besiege Chess use two complete FIDE boards and sets, with one King aside replaced by a third Queen or even an Ace, or a King and Queen with "missing" compounds. It occurred to me that similar variants might be played with fewer squares and a single FIDE army aside. One variant of this kind is Dave Reynolds' Lincoln Circular Chess, one of the more publicly played British Chess variants, but this makes for weak Bishops with its few files. One solution to this is to have four files in camp but widen to eight on empty ranks. This is the equivalent of each army being split between the camps of two 48-square cruciform boards, hence the name.

I then considered how to arrange the pieces. I considered arrays balancing major pieces between the two halves, and others concentrating them on one half. I eventually came up with six 2-player single-besiege variants. The first five can also be played double-besiege (circular - wrap the end ranks round), Moebius (wrap the ends round cz-fk, dz-ek, ez-dk, fz-ck), 4-player, or 4-player quadruple-besiege (join up each army's two camps). As half the subvariants are wraparound and half (an intersecting half) 4-player, I have ticked (among others) the Multiplayer and Round boxes for this page.

The last is a microregional in the style of Isis and Cam - or more closely Wey with its lack of King - but with multiple Rivers. This is because the setting is split between rivers, with the university in a town on the Essex Colne (Colchester) and the cathedral in one on the Chelmer (Chelmsford), with the Essex Blackwater in between. The variant name CoBlaChe is an acronym for the rivers. For once the Che does not stand for Chess, which is coincidentally a river name elsewhere! The Colne in this variant should not be confused with another of the same name, the other side of London. With CoBlaChe very much in the minority, and the River so changed from Xiang Qi, This page does not have the Xiang Qi box ticked.


balanced-strength version

balanced-strength for 4 players

unbalanced-strength version

unbalanced-strength for 4 players

Kamil version

Wildebeest version

Knighted-piece version

CoBlaChe version

For reference CoBlaChe has a River every four ranks dividing the board into four sections.


Groups of pieces include:
the FIDE Pawn, Rook, Knight, Bishop, Queen (R+B compound), and King common to most variants;
the "missing compounds" the Marshal (R+N) and Cardinal (B+N), added to the FIDEs for the all-compounds version;
and the pieces that are to the Knight what the Bishop and Queen are to the Rook, the Camel and the Gnu or Wildebeest, added to the FIDEs for the Wildebeest version.
CoBlaChe features the FIDE Pawn, Bishop, and Queen along with the Marshal, the Prince which moves like the King but is capturable, and a compound 1:1 and 3:0 leaper mentioned toward the end of my piece article Man and Beast 06: The Heavy Brigade, and known to problematists as the FROG. As with Wey the Prince reflects the setting being a latecomer both episcopally and academically. The Frog is named after a creature characteristic of the marshy lowlands associated with England's eastern counties, which also appears in both of Lewis Carroll's Alice books. I have also added two aside of this piece to Cam, which is set in another such county. It already appears in Trebucheté [Cha/Bat]turanga and now also in Symgi.
As usual the Bishop and Camel are colourbound and the Knight and Camel cannot lose the move. The Frog is an unbound compound of two differently-bound pieces, and can lose the move in 5 moves.


In 2-player subvariants play alternates between the two players starting with White. In 4-player ones it progresses anticlockwise starting with Red.

A Knight move, and each step of a diagonal move (though not necessarily the entire move), must be made within a solid block of squares with none missing. For example a Queen or Bishop may move dl-cm-bn but not cl-bm.

Pawns have an optional initial double-step noncapturing move in all variants except CoBlaChe, and can immediately be captured En Passant by anyone else's Pawns. CoBlaChe has no double-step Pawn moves. In 2-player variants, Pawns are confined to the files having squares on every rank. In 4-player variants Pawns cannot enter an adjacent-colour camp but must continue toward the nearest opposite-colour one.

There is no Castling.

Pawns reaching an enemy non-Pawn file can be promoted to any other capturable piece occurring in the array except in CoBlaChe, where Pawns crossing a River are promoted to Wazirs. Wazirs crossing the middle River may optionally be further promoted to a captured piece.

In CoBlaChe a Queen or Prince cannot move to a section occupied by an enemy Queen or Prince, even to capture that piece, but a Queen may move through such a section.

2-player Checkmate and Stalemate is as in FIDE Chess except in CoBlaChe, where victory is by capturing the Queen and Prince, a Marshal, a Bishop, and a Frog. In 4-player subvariants victory is by deliverig the last Checkmate.

This 'user submitted' page is a collaboration between the posting user and the Chess Variant Pages. Registered contributors to the Chess Variant Pages have the ability to post their own works, subject to review and editing by the Chess Variant Pages Editorial Staff.

By Charles Gilman.
Web page created: 2006-06-23. Web page last updated: 2016-03-18