Mahjong

• Chinese Classical Mahjong is the oldest of Mahjong, and was the version introduced to America in the 1920s under various names.
• Hong Kong Mahjong is the most common form of Mahjong, differing in minor scoring details with the Chinese Classical variety.
• Japanese Mahjong is a standardized form of Mahjong in Japan, found prevalently in video games. In addition to scoring changes, the rules of riichi and dora are unique highlights of Japanese Mahjong.
• American Mahjong is a form of Mahjong standardized by the National Mah Jongg League and the American Mah-Jongg Association that has the greatest divergence from traditional Mahjong, with the introduction of Joker tiles, the Charleston, as well as melds of five or more tiles, and eschewing the Chow and the notion of a standard hand. American Mahjong may also referr to the Wright-Patterson rules, used in the US military, which is closer to traditional Mahjong. Because of this divergence, the NMJL and AMJA variations (which differ from each other by minor scoring differences) is commonly referred to as Mahjongg (with two Gs).

The dealer now takes a block of 4 tiles to the left of the divide. The player to the dealer's right takes 4 tiles to the left, and players (counterclockwise) take blocks of 4 tiles (clockwise) until all players have 12 tiles for 13-tile variations and 16 for 16-tile variations. In 13-tile variations, each player then takes one more tile to make a 13-tile hand. In practice, in order to speed up the dealing procedure, the dealer often takes one extra tile during the dealing procedure to start their turn.

The board is now ready and new tiles will be taken from the wall where the dealing left off, proceeding clockwise. In some special cases discussed later, tiles are taken from the other end of the wall, commonly referred to as the back end of the wall. In some variations, a group of tiles at the back end, known as the dead wall, is reserved for this purpose instead. In such variations, the dead wall may be visually separated from the main wall, but it is not required.

Unless the dealer has already won (see below), the dealer then discards a tile.

Note: The dealing process with tiles is ritualized and complex to prevent cheating. Casual players, or players with Mahjong playing cards, may wish to simply shuffle well and deal out the tiles with less ceremony.

A turn consists of a player drawing a tile from the wall (or draw pile) and placing it in his hand. He then discards a tile to the table, which signals the end of his or her turn, and the player to the right plays next. It is good etiquette to announce the name of the discarded tile out loud. Many variations require that discards be placed in an orderly fashion in front of the player, and some may require that discarded tiles be placed face down.

When a player discards a tile, any other player may "call" or "bid" for it in order to complete a meld (a certain set of tiles) in his or her own hand. The disadvantage of doing this is that the player must now expose the completed meld to the other players, giving them an idea of what type of hand he or she is creating. This also creates an element of strategy, as in many variations, discarding a tile that allows another player to win the game causes the discarding player to lose points (or pay the winner more in a game for money).

In American Mahjong, however, Flower tiles are not instantly exposed and replaced, as they may be melded with other Flower tiles in the same group (in essence, they are treated as if they were another set of honor tiles) or be used as a requirement of a winning hand. Early versions of American Mahjong used Flower tiles as Joker tiles.

Rules governing discarding Joker tiles also exist: some variations permit the Joker tile to take on the identity of any tile, and others only permit the Joker tile to take on the identity of the previously discarded tile (or the absence of a tile, if it is the first discard).

Joker tiles may or may not have an impact on scoring, depending on the variation. Some special hands may require the use of Joker tiles (for example, to represent a "fifth tile" of a certain suited or honor tile).

In American Mahjong, it is illegal to pass jokers during the Charleston.

Pong or Pung (碰 pinyin peng, Japanese pon): 3 identical tiles. Can be created using any player's discarded tile; if formed with one, the player must say Pong and show the resulting set. The player can form a Pong at any time, after which he must discard a tile and the turn moves to the player's right.

Kong (槓 pinyin gang, Japanese kan): 4 identical tiles. Can be created using a discarded tile and always shown when formed. If a player forms the Kong from a discard, it is said to be an exposed Kong (明槓). If instead a player forms a Kong from four tiles in their hand, it is said to be a concealed Kong (暗槓). In either case, the player then draws from the other end of the wall and discards as normal. Note that once a Kong is formed, it cannot be split up (say, if you wanted to instead use one tile as part of a Chow). Sometimes it is advantageous to not declare a Kong if you have four identical tiles for this reason.

Chow (吃 chi, in some versions 上 shang): 3 tiles in sequence (circles, bamboos or numbers only). Can be created using a discarded title only during the player's own turn, ie. if the tile was discarded by the previous (left) player. Another player's Pong has priority over a Chow.

Eye (將 jiang, in some versions 眼 yan, also Pair): 2 identical tiles. Only one set allowed (and required), cannot be created with discarded tiles.

Note: Any discarded tile can be taken immediately at any time for any reason if doing so will win the game, and such a move has priority over any other claims. If a call to win overrides a call to form a Kong, such a move is called Robbing the Kong and may entail a scoring bonus.

Some variations of Mahjong, most notably Japanese variations, allow a player to declare riichi (立直 - sometimes known as reach as it is phonetically similar). A declaration of riichi is a promise that any tile drawn by the player is immediately discarded unless it constitutes a win. A player who declares riichi and wins usually receives a point bonus for their hand, while a player who declares riichi and loses is usually penalized in some fashion.

• 九種幺九倒牌 (kyuu shu yao kyuu tou pai): If, on a player's first turn, and with no melds declared, a player has nine different terminal or honor tiles, the player may declare the round to be drawn.
• 三家和 (san ka agari): If three players claim the same discard in order to win the round, the round is drawn.
• 四風子連打 (suu fontsu renda): If, on the first turn without any meld declarations, all four players discard the same wind tile, the hand is drawn.
• 四家立直 (suu ka riichi): If all four players declare riichi, the round is drawn.
• 四槓流れ (suu kan nagare): The round is drawn when the fourth kong is declared, unless all four kongs were declared by a single player. In this case, the round is drawn when another player declares a kong.

Winning

After the wind returns to East (ie. each player has been the dealer), a round is complete and the Prevailing Wind will change, again in the sequence East-South-West-North. A full game of mahjong ends after 4 rounds, ie. when the North Prevailing Wind round is over.

Chinese Phrase	English Interpretation	Meaning
將 (jiang)	Special Pair	Winning the round where the winning hand contains a pair of twos, fives, or eights.
缺五 (que wu)	No Fives	Winning the round where the winning hand does not contain a five.
獨聽 (du ting)	One-Shot Win	Looking for one tile to win the hand (for example, the middle tile in a Chow), and it was used to win the round.
自摸 (pinyin:zi mo, Japanese tsumo)	Self-Pick	Winning the round by drawing the necessary tile (as opposed to picking off an opponent's discard.
門清 (men qing)	Pure Hand	Winning the round without taking a discarded tile to form a meld.
斷么 (duan yao)	No Terminal Hand	Winning the round where the winning hand does not contain terminal or honor tiles.
槍槓 (qiang gang, Japanese chan kan)	Robbing the Kong	Winning the round off a discard when another player wishes to use the tile to form a Kong.
槓上開花 (gang shang kai hua)	Extra Tile Win	Winning the round from the extra tile drawn from declaring a Kong.
七對子 (qi dui zi)	Seven Pairs	Winning the round with seven pairs. Only applicable in 13-tile games.
八對半 (ba dui ban)	Eight and a Half Pairs	Winning the round with eight pairs and a 17th tile that matches any of the eight paired tiles (ie. seven pairs and a concealed pong). Only applicable in 16-tile games.
半求 (ban qiu)	Half-Begging	Winning the round where every meld in the winning hand is formed from a discarded tile, and the winning tile was drawn.
全求 (quan qiu)	All-Begging	Winning the round where every meld in the winning hand is formed from a discarded tile, and the winning tile is picked off an opponent.
門風 (men feng)	Seat Wind	Winning the round where one meld is of the winner's seat wind.
圈風 (quan feng)	Prevailing Wind	Winning the round where one meld is of the prevailing wind.
紅中 (hong zhong)	Red Dragon	Winning the round where one meld is of the red dragon.
青發 ('\'qing fa'')	Green Dragon	Winning the round where one meld is of the green dragon.
白板 (bai ban)	White Dragon	Winning the round where one meld is of the white dragon.
五門齊 (wu men qi)	All Category Hand	Winning the round where all five kinds of tiles (suits, winds, and dragons) are part of the winning hand.
一條龍 (yi tiao long)	Complete Sequence	Winning the round where three Chows form all the numbers from one to nine in a single suit.
平胡 (ping hu)	Sequence Hand	Winning the round where every meld is a Chow. Some variations make further restrictions that the eye must not be of an honor tile, and that it is not scored with Pure Hand or Self-Pick.
對對胡 (dui dui hu, Japanese 対々和 toitoi hō)	Triplets Hand	Winning the round where every meld in the winning hand is either a Pong or Kong.
槓上槓 (gang shang gang)	Kong-on-Kong	Winning the round from the extra tile drawn from declaring a Kong, which was itself made from the extra tile drawn from declaring another Kong.
小三元 (xiao san yuan, Japanese shō sangen)	Three Lesser Scholars	Winning the round with Pongs or Kongs in two of the three dragons and a pair of the third dragon.
大三元 (da san yuan, Japanese dai sangen)	Three Great Scholars	Winning the round with Pongs or Kongs of all three dragons.
小四喜 (xiao si xi, Japanese shō sūshī)	Four Small Blessings	Winning the round with Pongs or Kongs in three of the four winds and a pair of the fourth wind. Some variations further restrict this by disallowing the use of the prevailing wind or the seat wind as the pair.
大四喜 (da si xi, Japanese dai sūshī)	Four Great Blessings	Winning the round with Pongs or Kongs in all four winds.
混一色 (hun yi se, sometimes 湊一色 cou yi se, Japanese hon'ichi)	Mixed One Suit	Winning the round with honor tiles and tiles from one suit.
清一色 (qing yi se Japanese chin'ichi)	Pure One Suit	Winning the round with every tile in one suit, or with a hand entirely made of honor tiles.
混么九 (hun yao jiu)	Mixed Terminals	Winning the round with every tile being a terminal or honor tile.
清么九 (qing yao jiu)	Pure Terminals	Winning the round with every tile being a terminal.
十三么 (pinyin: shi san yao, Japanese 国士無双 kokushimusō)	Thirteen Terminal Hand	Winning the round with one of each one, nine, wind, and dragon, and a fourteenth tile that matches any of the other thirteen. Naturally, this applies only in 13-tile variations.
九蓮寶燈 (jiu lian bao deng, Cantonese 九子連環 gaau zhi lin wan)	Nine Gates	Winning the round with a ready hand consisting of 1-1-1-2-3-4-5-6-7-8-9-9-9 suited, with all tiles concealed. Careful analysis shows that such a hand is waiting for another tile of that suit, and will always have four sets and a pair. Some variations will relax this by allowing any variation thereof, as long as it contains 1-1-1-2-3-4-5-6-7-8-9-9-9 and a 14th tile. This is only applicable in a 13-tile game.
十八羅漢 (shi ba luo han)	Four Kongs	Winning the round with four kongs. Only applicable in 13-tile games.
天胡 (tian hu, Japanese 天和 ten hō)	Heaven's Victory	As the dealer, winning the round on the first turn (ie. with the tiles given after dealing and flower replacement)
地胡 (di hu, Japanese 地和 chi hō)	Earth's Victory	Winning the round by picking off the dealer's first discard. Sometimes also includes any player other than the dealer winning on their first turn.