Mahjong is a game for four players that originated in China. Mahjong involves skill, strategy, and calculation, as well as a certain degree of luck (depending on the variation played, luck can be anything from a minor to a dominant factor in winning). In Asia, mahjong is also popularly played as a gambling game. In the game, each player is dealt either thirteen or sixteen tiles in a hand, depending on the variation being played. On their turn, players draw a tile and discard one, with the goal of making four or five melds (also depending on the variation) and one pair, or "head". Winning comes "on the draw" by drawing a new or discarded tile that completes the hand. Thus, a winning hand actually contains fourteen (or seventeen) tiles.

Mahjong Competition Rules

The top three in the World Mahjong Championship in Tokyo, October 2002. In the middle: world champion Mai Hatsune, from Japan.

The first Open European Mahjong Championship, Nijmegen, the Netherlands, June 2005.

The winners of the second Open European Mahjong Championship, Copenhagen, Denmark, June 2007. From left: Kohichi Oda, Martin Wedel Jacobsen , and Benjamin Boas.

In 1998, in the interest of dissociating illegal gambling from mahjong, the China State Sports Commission published a new set of rules, now generally referred to as Chinese Official rules or International Tournament rules (see Guobiao Majiang). The principles of the new, wholesome mahjong are: no gambling, no drinking, and no smoking. In international tournaments, players are often grouped in teams to emphasize that mahjong from now on is considered a sport.

The new rules are highly pattern-based. The rulebook contains 81 ombinations, based on patterns and scoring elements popular in both classic and modern regional Chinese variants; some table practices of Japan have also been adopted. Points for flower tiles (each flower is worth one point) may not be added until the player has scored 8 points. The winner of a game receives the score from the player who discards the winning tile, plus 8 basic points from each player; in the case of zimo (self-drawn win), he receives the value of this round plus 8 points from all players.

The new rules were first used in an international tournament in Tokyo, where, in 2002, the first World Championship in Mahjong was organized by the Mahjong Museum, the Japan Mahjong Organizing Committee, and the city council of Ningbo, China. One hundred players participated, mainly from Japan and China, but also from Europe and the United States. Mai Hatsune, from Japan, became the first world champion. The following year saw the first annual China Majiang Championship, held in Hainan; the next two annual tournaments were held in Hong Kong and Beijing. Most players were Chinese, but players from other nations attended as well.

In 2005, the first Open European Mahjong Championship was held in the Netherlands, with 108 players. The competition was won by Masato Chiba from Japan. The second European championship in Copenhagen (2007) was attended by 136 players and won by Danish player Martin Wedel Jacobsen. The first Online European Mahjong Championship was held on the Mahjong Time server in 2007, with 64 players, and the winner was Juliani Leo, from the U.S., and the Best European Player was Gerda van Oorschot, from the Netherlands. The next European Championship will be held in Austria, in 2009.

In 2006, the World Mahjong Organization (WMO) was founded in Beijing, China, with the cooperation of, amongst others, the Japan Mahjong Organizing Committee (JMOC) and the European Mahjong Association (EMA). This organization held its first World Championship in November 2007 in the Chinese town of Chengdu, attended by 144 participants from all over the world. It was won by Li Li, a Chinese student of Tsinghua University.

Critics say that the new rules are unlikely to achieve great popularity outside of tournaments. They argue that regional versions are too well-entrenched, while the mahjong Competition Rules use many unfamiliar patterns. The new mahjong's advocates claim that it meant to be a standard for international events, not to replace existing variations.[citation needed]

Some other parties have also attempted to create international competition rules. The most noticeable one is the Zung Jung (中庸) Mahjong Scoring System, created by Hong Kong mahjong scholar Alan Kwan. Unlike the Chinese Official rules, Zung Jung is designed with simplicity as one of its design goals and aims to be suitable for casual entertainment as well as tournament play. Zung Jung is adopted by the World Series of Mahjong event held annually in Macau. The World Series of Mahjong was last held in September 2008, in which 302 participants took part. The main event had a prize pool of US$1-million, which was won over three days of play by Alex Ho, from Hong Kong. He won US$500K from the prize pool and a mahjong necklace designed by Steela+Steelo.