A rollback is when a pending set of moves is discarded. A piece may not move to a locked square. Each of these terms will be discussed in more detail below. The rules of Transactional Chess are identical to those of International Chess , except when noted below. In general, Transactional Chess is played much like Kriegspiel , with a referee and three boards.
Moves are only visible to an opponent after they are committed.
Once a player has successfully moved, they must decide if they wish to commit their current set of pending moves, rollback their current set of pending moves, or neither. It is illegal for a player to make an illegal chess move according to their own transactional view. The move may appear to be an illegal chess move according to the potential view. If a player's transactional view indicates that they have no legal move and their committed view also indicates that they are not in check, then a stalemate occurs. If a player's transactional view indicates that they have no legal move and their committed view also indicates that they are in check, then they have been checkmated.