- A player discarding a card of a suit of which another player has already 9 or more exposed in front of him shall pay the losses of all players as well as his own, if the discarded card enables the player with the exposed groups to complete his one-suit hand. 
A player discarding an Honour, Wind or Season when another player has already exposed 3 groups of Honours, Winds or Seasons, shall pay the losses of all players as well as his own, if the discarded card enables the player of the exposed groups to win with three doubles. 
In the above cases no settlement of scores is made between the losers. 
A player who calls attention to an error the correction of which would
affect adversely any other player shall, if the error is corrected, forfeit
his next turn to draw from the wall, and in the meantime shall not
participate in the play .
A player who mentions any feature of an opponent's play, or his apparent
objective when such mention may be detrimental to the opponent's interest,
or who gives any information concerning a dead discard, shall forfeit his
next turn to draw from the wall, and in the meantime shall not participate
in the play .
A player who causes an incorrect call of Pong or Kong by incorrectly
announcing a discard, shall forfeit his next turn to draw and in the
meantime shall not participate in the play .
When it is the forfeited turn of a player to draw, the discard made by
the player on his left may be chowed by the player on his right .
- After a player has grounded three or four Sets of one suit, or Honors,
or Terminals, any player who discards a tile which enables that player to
Mah-jongg with a hand of all One Suit, all Honors, all four Winds, all
Terminals, or all Green tiles, shall pay all losses unless (a) the discarder
has a Waiting Hand (wanting only one tile to Mah-jongg) which would give him
at least three doubles, exclusive of Flower Doubles; or unless (b) the
discarder holds no tiles in his hand except those which may subject him to
the above penalty. But exemption (b) shall be allowed only when the player
who claims it has drawn from the wall, and not after a Chow, Pong, or Kong.
After a player has grounded two Sets of Dragons, any player who discards
a Dragon of the third color which is ponged by the player with the Dragons,
shall pay all losses if the Dragon-holder then or later Mah-jonggs with the
Limit Hand known as the Three Great Scholars; unless the discarder has a
Waiting Hand or no choice of discard, as described in the preceding Law.
When the Insurance penalty is exacted, there is no settlement among the
Long, Short and Foul Hands
- A hand containing too many tiles is a Long Hand. A hand containing too
few tiles is a Short Hand .
- After East has made his first discard, a hand discovered to be Long or
Short shall not be corrected .
- A hand containing an incorrect grounded Set is a Foul Hand .
- A player with a Long, Short, or Foul Hand must continue to draw from the
wall and discard in his turn, and may chow, pong, and Kong .
- A player with a Short or a Foul Hand cannot Mah-jongg, but his hand
shall be counted in the same manner as that of any other non-winner, except
that it can double only for Flowers and doubling Sets .
- A Long Hand cannot Mah-jongg and shall be scored as zero .
- If Mahjong is declared mistakenly AND other players have displayed their hands, the hand ends. If a non-dealer, the player must pay 250 to each other non-dealers and 500 to dealer (1000 penalty points). If a dealer, player pays 500 to each player (1500 penalty points). If no other players' hands are displayed at the time of the false "out" the hand continues and the penalty sustained is that the offender can't go out until after her next turn. . In  the limit penalty is paid if the winning hand has be fully exposed otherwise it can be taken back and play continue.
- False Mah-jongg
86. If the call of Mah-jongg is found to be incorrect, the hand being
Incomplete, Short, Long, or Foul, the false call ends the game. The player
in error shall pay the full limit to East and half the limit to each of the
others. If he is East, he shall pay the full limit to each of the others. If
the false call of Mah-jongg was induced by the incorrect naming of a discard
and the discard named would have completed the hand, the penalty for the
false Mah-jongg shall be paid to the other players by the player who
incorrectly named the discard. In the event of a false Mah-jongg, East
retains the East position if not the player at fault. If East is at fault,
the East position passes.
- "Long hand," "Short hand," "Foul hand," or "Intentional Display": If at any time a player (for whatever reason) has more or less than 13 tiles (and one extra for each kong), that player may not go out and must continue to play. This player may try to cause a draw by playing defensively. 
- If a player melds an incorrect sequence, triplet or four and the next player has begun, the same penalty as above is levied. If the next player has not begun, no penalty is assessed. . Not penalty  but must correct it before the next player.
- If a chow, pong or kong is improperly declared, or if player changes mind, the player must forfeit 100 points to go in the "kitty" to go to the eventual winner of the game. If the game ends in a draw or if the offender wins the hand, the penalty is withdrawn. 
- If a tile is discarded by mistake, it may not be reclaimed. 
- If a player is ready and misses the needed discard, the player may not get the next discards until after her next draw from the wall. 
Go to 6 Rules for more or less than four players