Marseillais chess Marseillais chess Marseillais chess (also called Double-Move chess) is a chess variant in which each player moves twice per turn. The rules of the game were first published in Marseillais local newspaper "Le Soleil" in 1925. The variant became quite popular in the late 1930s with such chess grandmasters as Alexander Alekhine, Richard Réti, Eugene Znosko-Borovsky, and André Chéron playing it. A player can either move one piece twice or move two different pieces on his turn. Castling is considered a single move. When a player gives check on the first move, he loses the second move of his turn.
Pocket Mutation Chess chess. Instead of moving, a player can take one of their own pieces from the board and put it into the pocket, provided that the pocket is empty. If the piece is placed into the pocket from the last rank, it gets promoted to a piece of higher class. Otherwise the player has an option to mutate the piece into a different piece of the same class. The choice of mutating (or not) must be made at the time the piece is removed. White cannot use the pocket on the first move. The king cannot be placed into the pocket.