Royal Chess: In addition to its standard movement capabilities, the queen may be placed on any square the player’s king could have been moved to during the player’s turn. If the player’s king could have captured a piece, the queen may also capture that piece. If the player’s king could have castled, the queen may move to the king’s destined square (in this event, the player’s rook is not moved however, and the queen’s movement does not count as castling).
Both players simultaneously make their move.
Each player, either before or after their move, may place one captured piece on any unoccupied square on the board.
For instance, the White Player may check the black king on H8, then place a captured black pawn on H7 to block the king’s escape route. The Black Player may respond by placing a captured white pawn in the path of the piece checking his king (let’s say, a bishop), then moving the black pawn placed on H7 to H5.
Each player, once per game, can make two moves during one of their turns. These two moves cannot be used to place the opponent’s king in checkmate.
For example, on the eleventh turn White may move his queen and pawn. Black may respond by moving his knight and castling (if he hasn’t already moved twice in one turn during the course of the game).