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

Missionary cubic variants

Over the years I have taken more interest than many, even among Chess variant enthusiasts, in Chess in different geometries. It was to my interest in hex geometries that Jörg Knappen attributed my use of the Knave and Debtor in square-cell variants, and I am inclined to agree. With the help of comments from Ezra Bradford I have been able to meaningfully equate certain pieces on the geometry pioneered by Mark Thompson in Tetrahedral Chess with m:m:n and m:n:n leapers in the cubic one. However it is to the cubic geometry, the one first inspiring me to stumble upon the Chess Variant Pages all those years ago, that I keep returning. Here I look at adding Shogi-style pieces (and other Shogi features) to a game with pieces more familiar in 3d.

Existing variants can be modified without array modification, first by allowing return from capture and second by the Frontofhouse principle of symmetric pieces returning with only their most forward moves and having to recover the rest by promotion. Thus Rooks return as Wings, Bishops as Mitres, Queens as Princesses, Unicorns as Horns, Duchesses as Countesses, and Governors as Missionaries - and it is that last, 3d-specific, FO piece that gives this page its name.

Actually including FO pieces in the array - along with generals - is something that I did with Tunnelshogi, but that was dominated by relatively weak pieces. One way that I saw of using the full range of pieces was by taking the 6-rank version of Simple Tunnelchess and putting another layer of cells around it on every side, with the forward-only pieces added not directly behind their symmetric counterparts but behind and outward in the style of Mitred square-cell and Horn Rimmed cubic variants. Generals are then fitted in to fill out the back rank. Ranks being planes of 6x6 cells as a result of the added rim of cells, the front rank is filled with the Stockbrokers that I have made my usual front-rank piece for cubic-cell ranks this size or over.


The board has eight ranks numbered 1 (White's back rank) to 8 (Black's back rank), six filestacks lettered a to f, and six levels lettered u to z. Cells are designated by the level, then the filestack, then the rank. For example, White's Emperor is on wd2. The same array is use for three subvariants depending on how pieces are promoted. The following is a representation of each player's back and middle ranks, using the first three letters of each piece type.

Level u

Level v

Level w

Level x

Level y

Level z
same as level u


The EMPEROR is the King analogue. It makes one step in any of the 26 radial directions. There is of course one Emperor aside, and it must be kept out of Check.

Other middle- and back-rank pieces are grouped in six families. Each family comprises a symmetric linepiece moving any distance through empty intervening cells, after which it is named, a general moving just one step in the linepiece's directions and all other forward directions; and the original linepiece restricted to its forward directions.

symmetric linepiecepromoted symmetric linepiecegeneralforward-only (FO) linepiece
The QUEEN is the compound of the Rook and Bishop below The DIARCH is a Queen that can also move one step as a Unicorn The SKYGENERAL moves one step as a Queen or Horn The PRINCESS is the compound of the Wing and Mitre below
The DUCHESS is the compound of the Rook and Unicorn below The DOWAGER is a Duchess that can also move one step as a Bishop The FORESTGENERAL moves one step as a Duchess or Mitre The COUNTESS is the compound of the Wing and Horn below
The ROOK moves any distance in the 6 orthogonal directions The BARONESS is a Rook that can also move one step as a Governor The SUNGENERAL moves one step as a Rook or Missionary The WING moves any distance forward along its file
The GOVERNOR is the compound of the Bishop and Unicorn below The REGENT is a Governor that can also move one step as a Rook The SEAGENERAL moves one step as a Governor or Wing The MISSIONARY is the compound of the Mitre and Horn below
The BISHOP moves any distance in any of the 12 standard diagonal (SD) directions The POPE is a Bishop that can also move one step as a Duchess The MOONGENERAL moves one step as a Bishop or Countess The MITRE moves any distance in the 4 forward SD directions
The UNICORN moves any distance in any of the 8 nonstandard diagonal (ND) directions The USURPER is a Unicorn that can also move one step as a Queen The COASTGENERAL moves one step as a Unicorn or Princess The HORN moves any distance in the 4 forward ND directions
The STOCKBROKER is the Pawn analogue. It moves one step along any of the 9 forward radials with the restriction that the move must be:

(1) noncapturing if orthogonal (from Point via Broker);
(2) noncapturing if SD and to a file the same distance in/out;
(3) capturing if SD and to a file further in or out;
(4) capturing if ND, including "cutting a corner" with no change in distance in/out (from Saltire via Broker).
For examples of how its moves break down in individual files, see Brookschach or Courier Leapale. Its promoted form is the STOCKBWAITER (the B stands for Butler), which is the Steward analogue. The Stockbwaiter can move as both player's Stockbrokers, and also make a one-step noncapturing move along a same-rank SD or inward/outward orthogonal.


There is no double-step initial move, En Passant, Castling, or Cathedralling.

Promotion occurs on entering, moving within, or leaving the three ranks of the enemy camp. Pieces are promoted to, and return as, the following members of the same family:

symmetric linepiece promotable?noto crowned pieceno
symmetric linepiece returns?noas itselfas FO linepiece
crowned piece returns?N/AuncrownedN/A
general returns?noas itselfas FO linepiece
FO linepiece promotable?to generalto generalto symmetric linepiece
In all variants:
* neither crowned pieces nor generals are (further) promotable;
* crowned pieces return uncrowned and FO pieces (including Stockbrokers) return as themselves,
* Stockbrokers are promotable to Stockbwaiters, which are unpromotable and return ad Stockbrokers.

Check, Checkmate, and Stalemate are as usual.


Promotion rules have been designed so that Missiogi can be played with two distinguishable groups of four identical Shogi sets, and the other variants with two FIDE sets and four identical Shogi sets. The FIDE King is used for the Emperor and Shogi Points for Stockbrokers. The following Shogi/FIDE pieces are used for promotable/unpromotable pieces in each family. As the Goldgeneral is unpromotable in Shogi, promotion of the piece represented by it involves substituting the Shogi King.
* Queen family: Gold/Queen;
* Duchess family: Rook/Rook;
* Rook family: Wing/Pawn;
* Governor family: Bishop/inverted Rook;
* Bishop family: Silver/Bishop;
* Unicorn family: Helm/Knight.

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: 2011-08-27. Web page last updated: 2016-03-14