Heathen Europe Chess

As with GM4R, the first decision was how many of each piece to have. As both Unicorn and Elf are bound to 1 in 4 cells I decided to have 1 per binding aside, 4 aside in all. Keeping the set representable by 2 FIDE sets meant reducing not only Rooks, as in GM4R, but also Knights to 2 aside with inverted Rooks representing the latter and physical Knights representing Elves. This preserved the original army's 30 pieces aside - a Unicorn and two Elves more, a Rook and two Knights fewer. Since first posting I realised that with Gryphons losing the King's Partner significance in a different-armies variant they could be doubled, represented by both physical Queens, to raise total army strength. This raised pieces aside to 31, but allowed a simplifying of the rules.

The next stage was to decide on the board. What I was clear about was following my rotated-Raumschach model of camps along two opposite - or in a 4-player variant all four - vertical edges of the board, with Pawns moving accordingly. The original army size suggested either 3 or 5 levels, but attempts at this proved unsatisfactory and I spare you them. As I had intended to retain 16 Pawns, I eventually settled on 4 levels, with the cell below the King empty. Also, the small armies compared to the face-to-face Unionschach, Sachsenschach, and Leapale pointed to fewer cells, at least for the 2-player game. This ruled out having each level as a FIDE board, so I reduced the horizontal dimensions to 6, giving the same total of 144 cells as GM4R. As the 4-player variant does require the full 4 FIDE boards I do not include that here but cover it on the same page as AOF 4: Schism, which uses different pieces but similarly arranged.

Setup

Level b:

Level c:

Level d:

Pieces

	The KING moves one step along any of the 4 orthogonal and 4 diagonals. It must be kept out of Check. The 1 King aside starts on a middle level, mirroring its central position in most arrays.
	The ROOK moves any distance through empty intermediate cells in any of the 6 orthogonal directions. As straight linepieces the 2 Rooks aside start on the bottom level, much like in 3 level 4 player Chess.
	The KNIGHT makes 2:1:0 leaps. On an infinite cubic board it would have 24 such moves, but the moves never exceed 20 on a 4-level board. As on a 2d board, but unlike on a hex-prism one, a Knight cannot return to a cell in an odd number of moves, as it always switches between the two Bishop bindings. The 2 Knights aside start on the top and bottom levels framed by linepieces, mirroring their just-in-from-the-corner location in the FIDE array.
	The PAWN moves like in Raumschach. Its noncapturing move is one step along either horizontal orthogonal away from its own camp. Its capturing move is one step in any root-2 diagonal with coordinates either in one of its noncapturing directions and either vertical direction, or in both its noncapturing directions. There are 16 Pawns aside.

	The ELF makes 3:1:1 leaps, that is, moves 3 planes in one dimension and 1 in each of the other two. It is bound to the same cells as the Unicorn below, but like the Knight it alternates between Bishop bindings. The 4 Elves aside, covering the board between them, start on the middle levels.
	The GRYPHON makes one step on any root-2 diagonal (like a Bishop) but then turns 45° (but not 90°) and continues in the same plane as a Rook. The 2 Gryphons aside start on a middle level flanking the King, mirroring the single Gryphon's position in the Grande Acedrex array and that of Kings' partners generally.
	The UNICORN moves any distance through empty intermediate cells in any of the 8 root-3 diagonal directions. Each Unicorn is bound to either half the dark cells of the odd levels and half the pale cells of the even ones or vice versa. As straight linepieces the 4 Unicorns aside, covering the board between them, start on the top and bottom levels.

Rules

There is no Castling as Kings and Rooks are not in suitable relative positions. Nor are there any other special moves corresponding to GM4R's Elephant Charge or Enlightened Move.

A Pawn is promotable after making 5 or more moves, unless it could have but did not make a double-step move, in which case the minimum is 6. Remarkably this rule makes just as much sense here as it does in the very different GM4R. If the Pawn reaches the far vertical edge promotion is compulsory, otherwise it is optional. Promotion on the top and bottom levels in to Rook, Unicorn, or Knight and on the middle level to Gryphon or Elf. A Pawn promoted once cannot then be promoted further, so it may be worth delaying promotion in the hope that capturing as a Pawn will lead to promotion to a piece more useful in conjunction with existing pieces.

Check, Checkmate, and Stalemate are as normal.

Notes