Additional Rules.

Imperfect Set. If the set is found to be incomplete, the current deal is void unless a player has wooed, but scores of previous deals stand.

Exposed Tile. If a tile is exposed in building the wall the tiles must be reshuffled. If a tiles is exposed when drawing another, it must be shuffle cards with six adjacent stacks and that section of the wall rebuilt.
Incorrect Set. If a player ground tiles that do not form a correct set, he may retract or correct the set before the next hand has discarded; otherwise, he must play with a foul hand (too few tiles).
Foul Hands. A hand that is foul or incorrect may not woo. A long hand (too many tiles ) scores as zero. A short or foul hand may score its basic value, but no doubles (factors )may be applied.
Incorrect Claim. If a player takes or claims a discard that he cannot use, he may correct the error without penalty before the next hand has drawn. The discard is open to claim by the other players; otherwise, it is treated as an exposed tile and is reshuffled.
False Woo. If a call of woo or mah-jongg is found to be incorrect because the hand is incomplete (short or long), the play ends. If the offender is East, he must pay the limit to each other player; if another player offends, he must pay the limit to East and half the limit to the other two. There is no settlement between the other three players. East keeps his position if he was not the offender; but he loses it if he was the offender and the positions rotate.

Mah-Jongg Variations

Of many different ways of playing and scoring in Mah-Jongg, the most widely circulated method is that of the National Mah-Jongg League, Inc., 250 West 57th Street, New York, N.Y. 10019. While that League’s official standard hands and rules change slightly each year, and such changes are sent to their members (membership is $1 a year), the principal differences from the procedure described in the foregoing pages are as follows:
In the so-called modern game, flowers are wild and there are eight big jokers, which are also wild. Any hand made without a big joker is paid double. Big jokers may be discarded at any time during the game and called the same as the previous discard. Big jokers may be used to replace any tiles in any hand. A big joker may be replaced in any exposure with a like tile or tiles by any player, whether picked from the wall or in a player’s hand, when it is the player’s turn. If a playplayer declares mah-jongg or woo, and all jokers in exposures have been replaced and no jokers are in concealed part of hand, the player is paid double. This is called a no-joker hand.
After the hands have been drawn, but before play begins, there are one or two Charlestons, or passes of tiles. That is, each player passes three tiles to his right-hand neighbor; then (having received and seen the tiles passed to him), he passes three to the find player opposite him; then, in the same manner, he passes three to his left-hand neighbor. By agreement of all players, there may then be a second Charleston with the first pass to the left, the second to the player opposite, and the third to the right. Sometimes a blind pass is permitted on the last pass of a second Charleston; that is, a player may pass along the three tiles passed to him, without looking at them. Flowers may be passed during any pass or Charleston, but big jokers may never be passed (except in the blind pass).
East does not receive or pay double. When a player picks his, own Mah-Jongg tile, all players pay double the value of the hand. When a player woos on a discarded tile, the person who discarded the tile pays the winner double the value of the hand. All other players pay the single value.
No more than four may play in a game; but a fifth player, after looking at all four hands, and after the Charleston but before the first play, may write on a slip of paper the name of the player he bets on. He then pays in full if another player wins, but collects from the three losers in equal shares if his chosen player wins. , In the same manner six may participate, there being two “bettors.”
The game ends only when a player woos or mah-jonggs. The winning poker hand has a predetermined value, according to the schedule adopted for the game, and is not increased by doubles. The entire wall may be drawn and, if no one goes out, the game is void.
A hand may be played concealed or exposed. Any hand may be played concealed; but then a discard may be claimed only to woo. A hand becomes exposed when a discard is claimed to complete a kong, quaint, or sextette; where upon, the set must be exposed on top of the player’s rack. (A discard may be claimed only to complete these sets or to go out.) Concealed and exposed hands score the same.
A typical list of hands and values follows:

If a player claims to be out when not having a valid combination, his hand becomes dead; the others continue without him, and he pays the winner at the end.