Mahjong is a game that originated in China; commonly played by four players (with some three-player variations found in Korea and Japan). Similar to the Western card game rummy; mahjong is a game of skill; strategy and calculation and involves a certain degree of chance. In Asia; mahjong is also popularly played as a gambling game (though it may just as easily be played recreationally).

The game is played with a set of 136 tiles based on Chinese characters and symbols; although some regional variations use a different number of tiles. In most variations; each player begins by receiving thirteen tiles. In turn players draw and discard tiles until they complete a legal hand using the fourteenth drawn tile to form four groups (melds) and a pair (head). There are fairly standard rules about how a piece is drawn; stolen from another player (melded); the use of basic (numbered tiles) and honours (winds and dragons); the kinds of melds; and the order of dealing and play. However there are many regional variations in the rules; in addition; the scoring system; the minimum hand necessary to win varies significantly based on the local rules being used.