Dominion Cues Shogi

Dominion Shogi

A house variant: a 3-wide extension arm attached to all four edges of the board. Drop a piece onto any arm and all four spin 90° for the rest of the game. Pieces can move freely between the main board and the arms, but no piece may promote once it's on one -- and only an attacking push (never a retreat) can reach the far edge of the arm behind either player's own back rank.