Back in the 1980’s I invented a Shogi variant which transported the Shogi pieces to a 3-D board. The game was described somewhat inaccurately in Michael Keller’s World Game Review. I take full responsibility for the inaccuracy, blaming it on my poor effort to communicate the game to Keller.
The game is now on Wikipedia, using Keller’s description. I recently got a communication pointing out that the pieces were too lonely on a 9x9x9 playing field. I agree. I never meant for the game to be played on such a large field. It is now time for me to clear up the inaccuracies.
Space Shogi should be played on a field consisting of 81 cubes arranged 3x3x9. Think of the field as consisting of a row of three cubes, each one subdivided into nine smaller cubes. White occupies the 3x3x3 cube on one end of the field, and Black occupies the cube on the other side of the field. The middle cube is vacant.
The pieces are identical to those of orthodox Shogi, and their moves are extended to the third dimension. They are:
All the rules of orthodox Shogi apply, including captures, drops, and promotion of the pieces. The array is shown below, as are diagrams of the moves of the pieces.