A hexagonal chess on a rhombus — 81 cells arranged as a 9×9 parallelogram of hexes. All pieces move exactly as in Brusky's variant, on a very different-shaped board.
The 81-cell diamond has nine files (a–i) and nine ranks (1–9). Every hex on the rhombus is playable — no missing corners. White starts on ranks 1–2, Black on ranks 8–9.
White's back rank (rank 1) reads, from left to right: R N B K B Q B N R. Black's back rank (rank 9) is the mirror — R N B Q B K B N R — so the two kings start at opposite ends of the board: White's on file d, Black's on file f, with the queens facing them. The three bishops sit on files c, e, and g — one bishop per hex colour, matching classical hexagonal-chess convention.
Nine pawns start on the third rank, two steps ahead of the back-rank pieces.
Slides any distance along the six orthogonal directions — edge to edge.
Slides any distance along the six hex diagonals, locked to one of the three board colours.
Rook plus bishop — twelve directions in total.
One hex in any of the twelve directions, never into check.
Two hexes in one orthogonal direction, then one at 60° — twelve destinations, jumping over anything in between.
Moves to either forward neighbour and captures only on the two slanted diagonals — never on the diagonal directly ahead. Each forward square is independent: a blocker on one does not freeze the pawn.
Every piece moves exactly as in Brusky's variant — only the board shape differs. Rooks and queens slide along the six orthogonal hex directions; bishops and queens along the six hex-diagonals; knights make the standard 12-destination hex knight leap.
There are two castles, as in Brusky's. On the kingside — the rook nearer the king, on file a for White and file i for Black — both the king and the rook move two fields. On the queenside — the far rook, file i for White and file a for Black — both pieces move three fields. All hexes between king and rook must be empty, the king may not castle out of, through, or into check, and neither piece may have moved.