The goal of the game is to go out by completing a hand composed of four sets of three tiles each, plus a pair, thus totaling fourteen tiles. A set may also be composed of four tiles, the total of fourteen being increased by one for each such set.
There are four kinds of sets (or basic tile combinations) that can be used to collect a winning hand: Chows, Pungs, Kongs and Pairs.
A regular winning hand must always contain one, and only one pair. Any hand containing four sets of Chows/Pungs and Kongs (in any combination of these sets) – and a pair – is a valid winning hand.
In American games there are also two other requirements on the winning hand:
The sets can be composed either of tiles drawn from the Wall on player's own turn, or by completing a set by claiming a tile discarded by another player. Sets composed entirely of tiles drawn from the Wall are called concealed sets. Sets completed by claiming the missing tile from another player's discard are called melded (or exposed) sets.
The bonus tiles (Flowers and Seasons) are not used for completing the sets but are replaced immediately when received by regular tiles drawn from the open end of the Wall (not from the Dead Wall).
In addition to regular winning hands consisting of four sets and a pair (not including more than 1 Chow and not including tiles from more than one suit), the rules acknowledge numerous special hands, where there are no restrictions on number of Chows and different suits. Several of these special hands are irregular hands.
The game is played counter-clockwise, that is, the players receive tiles from the Wall and make their discards in the following order: East, South, West, and North.
East, who at the beginning of the deal receives 14 tiles, starts the deal (bonus tiles, if any, must have been replaced immediately after the tiles have been dealt, for details, see Preliminaries). If East cannot go out, he discards one of the tiles in his hand.
It is customary (though not obligatory) that a player names his discards.
The discards are placed face up in the center of the table (inside the Wall), but in a random manner so that it cannot be readily seen which tile is discarded by which player, or in which order.
When a tile is discarded it may be claimed by any player for Pung, Kong or Mah Jong ("going out"). If no player claims the tile for Pung, Kong or Mah Jong, it can be claimed for a Chow by the player next in turn (i.e., the player on the discarder's right: accordingly, it is said that a player can claim a tile for a Chow only from the player on his left). If no one claims the tile for a Chow, the next player in turn draws from the open end of the Wall, and discards (unless he can go out).
Tiles placed amongst the discards and not claimed by anyone are considered dead and cannot be used later during the deal.
The game continues like this, until one of the players succeeds in completing his hand and declares out, or until there are no more tiles left to play in the Wall, in which case the deal is said to end in a draw (or 'wash-out'). When a player succeeds in collecting a complete hand and declares out all hands are exposed for calculating the scores. After the point calculation and payments, the next deal is started.
The complete game of Mah Jong consists of four rounds. The game starts with East round, the remaining three rounds being South, West and North. Each round consists of at least four deals so that each of the four players has held at least once the East position (that is, acted as a dealer). The deal passes in counterclockwise order (the player who was South becomes East, the former West becomes South, North becomes West and East becomes North) after a hand is won by a non-dealer (South, West or North), but is not changed if East wins, or if the deal ends in a draw. Thus a round can consist of more than four deals. It changes when the player who first held the East seat during the round has lost the deal and receives it again (thus the same player starts each of the four rounds).
Each player starts the game with 10,000 points. The total of player's points stays always the same during the game: e.g., when the players start with 10,000 points, the total of points will be 40,000 points at any stage of the game. The player who has the highest score after the last deal of the game is played is the winner of the game.
Whenever a player discards a tile, the other three players may claim the tile either to go out, or to complete a Pung, Kong or Chow (the latter, when not being the set that completes the hand, being allowed only to the player sitting to the right of the discarder).
If two or more players claim the same tile, the order of precedence is (from the most valuable to the least valuable): winning, Kong, Pung and Chow. If two or more players claim the same tile for going out, the player who would be first in turn after the discarder, will get the tile.
If a player holds in his hand a serial pair (two tiles forming a part of a sequence of three tiles, e.g. , Bamboo 3-4 or Character 2-4), and the player on his left discards a tile that completes the serial pair, the former can claim the discard by saying 'Chow'. He then exposes the two tiles in his hand and places them, along with the claimed tile, above his hand, arranged as a sequence. It is not a practice in American games to mark the claimed tile.
Note that concealed Chows are not declared but kept in hand, thus retaining flexibility that allows re-arranging of tiles to alternative sets.
If a player can go out by completing a Chow, he should not say "Chow", but instead declare "Out" (going out by completing a Chow set is not considered "Chowing", but going out, so there are no claiming restrictions).
Note that Chows cannot wrap around (e.g., it is not legal to compose a Chow of Bamboo 9-1-2).
If a player holds in his hand two identical tiles and another player discards a tile that completes the set to Pung, the former can claim the discard by saying 'Pung'. He then exposes the two tiles in his hand and places them, along with the claimed tile, above his hand, arranged as a triplet. After that the player discards and if the tile is not claimed, the next player in turn draws from the open end of the Wall. Accordingly, it is possible that one or two players between the discarder and the claimer lose their turn.
It is not a practice in American games to mark the discarder.
Note that concealed Pungs are not declared but kept in hand, thus retaining flexibility that allows re-arranging of Pungs to alternative sets.
If a player can go out by completing a Pung, he should not say "Pung", but instead declare "Out".
There are three kinds of Kongs (sets composed of four identical tiles).
If a player holds in his hand three identical tiles and another player discards a tile that completes the set to Kong, the former can claim the discard by saying 'Kong'. He then exposes the three tiles in his hand and places them, along with the claimed tile, above his hand, arranged as a quadruplet. After that the player gets a supplement tile from the tail end of the Wall, and if he cannot go out on it, discards a tile of his choice, and if the tile is not claimed, the next player in turn draws from the open end of the Wall. Accordingly, it is possible that one or two players between the discarder and the claimer lose their turn.
It is not a practice in American games to mark the discarder.
If a player has earlier melded a Pung (an exposed triplet), and he draws the fourth identical tile from the Wall, he is allowed to promote the melded Pung into a melded Kong (a player cannot claim another player's discard to promote a melded Pung into a melded Kong, since no set can contain more than one tile from discards). He is not forced to make immediate declaration but is free to declare Kong any time it is his turn (also after having claimed a tile for a Chow or Pung).
After the declaration the player shows the fourth identical tile in his hand and places it face up beside the previously melded Pung, arranging the tiles as a quadruplet.
After the declaration the player gets a supplement tile from the tail end of the Wall, and if he cannot go out on it, discards a tile of his choice and if the tile is not claimed, the next player in turn draws from the open end of the Wall.
If a player holds in his hand three identical tiles and he draws the fourth identical tile from the Wall, or receives it as a supplement tile from the tail end of the Wall, he can declare a concealed Kong. He is not forced to make the declaration immediately after the fourth tile is drawn, but is free to declare Kong any time it is his turn (also after having claimed a tile for a Chow or Pung).
He then exposes the four tiles in his hand and places them above his hand, arranged as a quadruplet. The first and fourth tile are turned face down to mark the set concealed.
A concealed Kong must always be declared. It is not possible to have a non-melded Kong set in hand (as there would then be too few tiles to make four sets and a pair). In a loser's hand four identical tiles are counted as a concealed Pung.
Some players mark concealed Kongs by turning the two middle tiles face down, instead:
Note: In patterns like Three concealed triplets only concealed Kongs are considered as concealed triplets.
When a player needs only one tile to go out, he is said to be "calling" the winning tile. The winning tile can be obtained either by drawing from the Wall (in which case the player is said to go out self-drawn), from the Dead Wall as result of declaring a Kong (in which case the player is said to got out self-drawn on a supplement tile), or by claiming another player's discard (without any restrictions). The fourth possible way to go out is robbing a Kong, but this is normally not supported in American games.
There is no need to declare a calling hand.
If a player promotes a melded Pung into a melded Kong by using a fourth identical tile he has drawn from the Wall (or Dead Wall), a player with a calling hand can rob that tile and use it to complete his hand and go out (if jokers are not used, the completing set is always a Chow). The player who tried to compose the Kong is considered a discarder of the winning tile.
Note that the player whose Kong is robbed should not take a supplement tile, but if he has done so, and it is a Flower or Season, a tile that allows him to make further declarations of Kongs, or a tile that allows him to go out, the Kong may not be robbed. On the other hand, if the player has taken the supplement tile and his Kong is robbed, he should replace the supplement tile.
If there are no tiles left in the Wall and no one has succeeded to go out, the hand is declared a draw. No score is counted and East keeps the deal for the next hand.
The deal is not ended until the next player who is in turn cannot make his draw from the Wall. E.g., if a player draws the last tile of the Wall, he must still make a discard (which gives other players a chance to go out on the last discard). The last discard can also be claimed to a set without going out, but in this case the claimer must in turn make a discard. This continues until a tile is claimed for going out or remains unclaimed, in which case the deal ends in a draw.