Courier Leapale

My variant Courier Kamil takes the Courier feature of adding to the traditional Rook and Ferz the corresponding pieces in each other's directions, and also applies it to the Elephant and Knight. Here is a variant extending the families of pieces to 3 dimensions in a similar pattern.

As the non-coprime radial leapers are so weak I decided to make all kinds of piece compounds, in the radial cases the Royal, Ducal, and Baronial pairs of direction types. I decided to have these radiating horizontally, vertically, and diagonally from the centre of the back rank. As the potential number of piece types would leave a back rank of an 8x8 square sparsely filled, and 7x7 would undermine the symmetry for the radial leapers, I settled on the 6x6x6 board of Unionschach, Sachsenschach, and Leapale. As the linepieces are the same as those of the Leapale array illustrated, with leapers surrounding them "beyond the pale", Leapale was the obvious name to attach to Courier to name this new variant. Combining two seven-letter words also gives a fourteen-letter name, the kind best suited to the post-your-own-item address builder! Ranks are numbered 1-6, levels lettered u-z (the first character of the cell), and filestacks - vertical groups of files - lettered a-f (the middle character, before the rank number).

Setup

Levels v and y

Level w

Level x

Pieces

The Emperor and three types of promotee-only piece move along any of the 26 radials:

	The EMPEROR moves one step in these directions, and must be kept out of Check. The one Emperor aside starts on file wd. The name indicates a more powerful King.
	The ARCHDUKE also moves one step in these directions but, like all pieces except the Emperor, is capturable. The name indicates a son of an Emperor and/or Empress.
	The EMPRESS moves any distance through empty intermediate cells in these directions. The name indicates a more powerful Queen.
	The ALIBUCK moves two steps in these directions. The intermediate cell may be empty or occupied. The name is a composite of its components, Alfil(=Elephant)+Dabbaba+Eunuch.

	The PRINCE moves one step in these directions. The one Prince aside starts on file wc, beside the Emperor. The name indicates the son of a King and/or Queen.
	The QUEEN moves any distance through empty intermediate cells in these directions. The four Queens aside start on files wb/we/xb/xe, each beside a stepper. The name comes from 2d Chess.
	The ALIBABA moves two steps in these directions. The intermediate cell may be empty or occupied. The four Alibabas aside start on files wa/wf/xa/xf, each beside a Queen, and covering the whole of their odd ranks between them. The name is a composite of its components, Alfil(=Elephant)+Dabbaba.

	The DUKE moves one step in these directions. The one Duke aside starts on file xd, below the Emperor. The name indicates the highest rank of nonroyal nobility.
	The DUCHESS moves any distance through empty intermediate cells in these directions. The four Duchesses aside start on files vc/vd/yc/yd, each above or below a stepper. The name indicates the wife of a Duke.
	The DYBBUK moves two steps in these directions. The intermediate cell may be empty or occupied. The intermediate cell may be empty or occupied. The four Dybbuks aside start on files uc/ud/zc/zd, each above or below a Duchess, and covering the whole of their odd ranks between them. The name is a composite of its components, Dabbaba+Eunuch.

	The BARON moves one step in these directions. The one Baron aside starts on file xc, diagonally below the Emperor. The name indicates the lowest rank of nobility.
	The GOVERNOR moves any distance through empty intermediate cells in these directions. The four Governors aside start on files vb/ve/yb/ye, each diagonally above or below a stepper. The name derives from a position of the sovereign in the Church of England.
	The ELK moves two steps in these directions. The intermediate cell may be empty or occupied. The intermediate cell may be empty or occupied. The four Elks aside start on files ua/uf/za/zf, each diagonally above or below a Governor, and covering the whole of their odd ranks between them. The name is a composite of its components, Elephant(=Alfil)+Eunuch.

	The GNU makes any 2:1:0 or 3:1:0 leap, and cannot be blocked. The four Gnus aside start on files ub/ue/zb/ze, as planar pieces surrounded by compounds with a triaxial element. The name is from 2d Chess variants - including Courier Kamil, where it is a promotee - although it is a much stronger piece in 3d.
	The OBERON makes any 2:1:1 or 2:2:1 leap, and cannot be blocked. The four Oberons aside start on files va/vf/ya/yf, as triaxial pieces adjacent to the planar pieces. The name derives from being an oblique counterpart to the Baron, in terms of the 2:3 ratio of its SOLLs.
	The pieces covering the front ranks are STOCKBROKERS, which I devised for variants whose ranks are squares larger than 5x5 (compare the Coheir of Paired Linepiece Tunnelchess as such a piece for smaller than 5x5). It moves one step along any of the 9 forward radials with the restriction that the move must be:

Rules

Stockbrokers reaching the far rank must be promoted. As Pawns in Courier Kamil are promoted not to the simple array pieces but to non-array two-piece compounds, Stockbrokers in Courier Leapale are promoted not to the two-piece-compound array pieces but to three-piece-compound non-array ones - the Archduke, Empress, and Alibuck. As oblique moves do not extrapolate as tidily as radial one, I drop promotion to any oblique piece.

Check, Checkmate, and Stalemate are as normal. A player can also win by a promotion that results in having three Archdukes, three Empresses, and three Alibucks - an incentive not to just boringly always promote to Empress.