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

Trebuqi

In a previous variant, now being discontinued, I regretted its lack of mirror (as opposed to rotational) symmetry and a shortfall in the pieces' similarity to those in Xiang Qi (on which I modelled it). This variant addresses both of these. Another regret was that the variant could not be extrapolated from 2 to 3 players on the same board, as can the likes of Anglojewish Chess (curved linepieces) and Hexgi (based on Shogi). Another discontinued variant addressed this, while also applying to 3 players my idea of a River each for 4 players.

It then dawned on me that I could, as I had in Caliph Qi and Gnu Qi, further apply the idea to 2. That addresses the symmetry issue by allowing an odd number of ranks, the middle one the longest and reducing by one cell with each rank's advance or retreat therefrom. Following the practice of allowing the River-restricted piece across its own River also gives a larger range in which to use the more bound Elephant analogue that the Trebuchet is than the Dabbaba of the discontinued variants. For more on this piece and the Vicbaba see my piece article Man and Beast 06: The Heavy Brigade.

It may be possible to extrapolate to 3 players on a still larger board with sides of alternating lengths. Depending on responses here I might pursue further the idea of a Xiang-Qi-like 3-player variant on a pure hex board.

Setup

Rivers are between each player's 4th and 5th ranks, neatly dividing the board into areas or 30, 31, and 30 cells. This near-equality was not planned, but I am pleased at how it compensates, courtesy of the changing rank length inherent in a Wellisch-orientation board, for them being unequal numbers of ranks.

Pieces

The GENERAL, ROOK, and CANNON are the pieces from Xiang Qi itself, extended to six directions instead of the original four.
The TREBUCHET moves exactly three cells in any of the 6 orthogonal directions. The version used in this variant is a stepping one, blockable by any intervening piece. The name comes from a war machine (by analogy with Dabbaba) whose name starts with the Tr- of tri- (for 3) replacing the D of di- (for 2). I use this piece as Elephant analogue as the 9 in both "moves a distance of root-9" and "bound to 1 in 9 cells" is closest to the corresponding figure of 8 for the Elephant.
The VICBABA moves one step along any of the 6 hex diagonals, or two along any orthogonal. The version used in this variant is stepping regarding its Dabbaba component, blockable on the halfway cell (in contrast to Panal, which uses the leaping version). I use this piece as Knight analogue as it is unbound in this geometry, Viceroy and Dabbaba bindings being independent. This is not true of the Fezbaba on a square-cell board, or of either compound on a cubic one. The name follows the tradition of Alibaba and Waffle.
The POINT is the piece from Xiang Qi itself, extended to two forward directions from the original one. This is a side effect of the Wellisch orientation and reason why Wellisch himself felt no need to simulate the Pawn's divergent character.

Rules

A General cannot cross the near River. No other piece is affected by the near River.

As Elephant analogues, Trebuchets cannot cross the far River. Points crossing the far River are promoted by adding the single-step moves in the two sideways directions. Rooks, Cannons, and Vicbabas are unaffected by that River, and Generals cannot reach it.

Generals are barred from facing each other along any orthogonal without an intervening piece.

Three alternative definitions of victory define three subvariants:
(1) checkmating one General;
(2) capturing one General and checkmating the second;
(3) ditto but retaining both one's own Generals, in which case losing a General each is a draw. I would be interested in any analysis of which gives the best play.

Notes

The game can be played with a standard 91-cell hex board and a Xiang Qi set, using Ferzes for the paired generals and non-Fortress pieces as themselves or their analogues.

The 30-cell thirds to which the sections separated by Rivers approximate correspond to thirds of the XQ board (as if it had been rotated by 90° and had the one River replaced by 2).

Only after posting this variant did I notice Panal with its similar Knight analogue. Had I seen it earlier I might have come up with this one a lot earlier!

It occurs to me that a subvariant with the central cell missing might be interesting. Vicbabas would be unable to cross the void, as either component. Wellisch could also work with such a void, but Glinski and McCooey could not.

There is no Ferz analogue, just as Wellisch Hex has no Bishop analogue.

Although both players' Trebuchets can enter the central section between the Rivers, one Trebuchet cannot capture another as they have different bindings. One player's Trebuchets can however cover each other, as XQ Elephants can, as they share a binding. They can reach 2 cells on the back rank, 3 on the rank just behind the near River - somewhat like the XQ Elephant's first two accessible ranks - but increasing again to 4 on the rank just behind the far River as against the XQ Elephant's return to 2 just behind the single River.


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By Charles Gilman.
Web page created: 2007-06-10. Web page last updated: 2016-02-26