Duchess - a triangular cell chess variant

Duchess

I created a two player trigonal chess variant some years ago.  The game is an adaption of the three player chess game by Noris Schach: https://boardgamegeek.com/boardgame/149886/noris-schach  

In the original three player version, the extra piece (known as the cardinal), did not transfer over well for my two player game variant.  So I renamed this piece, the duchess, as it has a entirely different movement pattern and behaviour.

Initial set up:

Piece movement:

The game is played according to the usual rules of standard chess, with the exception of one extra piece and additional directions of movement resulting from the triangular cells.  Castling rules still apply along the back rank (where the king moves two cells to the right or left and the rook that's nearest, hops over), except that both king and rooks movement, mimics the duchess instead of the rook in standard chess.

The knight (far right) is capable of long and short jumps.

Below left and centre: red circles indicate pawn moves, white circles typical captures and black disk, en passant capture.

Below right: the duchess can move to any unoccupied triangular cell along the 'tram lines' unless blocked, i.e, any occupied triangle blocks all triangles beyond it.

Lite version

Less number of cells, seven pawns instead of nine, no queen or duchess.  However, if a pawn reaches the opponents back rank, it can be promoted to any other piece, including a queen or duchess.

A special thank you to David McCooey for his inspiration and suggestions.

Visual Polyhedra