Working from the theory that the queen is merely a combination of a rook's and a bishop's powers, Freeling created the combination of each with a knight (as in the earlier Capablanca chess). The Marshall moves like the knight and the rook of standard chess; the Cardinal moves like the knight and the bishop.
Two other variations are in piece setup, and in pawn promotion. The pieces are set up as in standard chess, but on the player's second and third ranks, rather than the first and second. The rooks are then left in the first rank, eliminating the need for castling, and speeding their release into the game.
Pawns may elect to promote upon reaching the eighth or ninth rank, but must promote at the tenth.