When a player calls a tile and places it on the flat part of their rack or exposes tiles from their rack, they are committed to taking that discard. They may add or take away from the exposure before discarding.
If a player inadvertently exposes the wrong tiles or exposes too many jokers, they can add to or take away from the current exposure as long as they have not discarded. After a player has discarded, exposures on their rack cannot be changed.
Tournament Rules are created to raise the competition level of the game and to ensure it is played fairly. Some groups enjoy competition so much, they play by tournament rules. Typically, tournament rules do not apply to social games.
One might think that a player's turn begins when the previous player discards a tile but that is not the case. The reason for this is that turns can be interrupted when another player claims the discard to make an exposure. Therefore, a player's turn officially begins when they either pick a tile from the wall or call a discard.
The value of a Jokerless hand is doubled. For example, if a player declares mah jongg on a hand that can use jokers but it is jokerless, the value of the hand is doubled. If the player self-picks their winning tile, the value is doubled again.
A variation created by the National Mah Jongg League supports a 5-player game. Some people call this, "playing with a bettor", or "5th player betting" Here's how it works
