Mahjong or mah-jongg is a tile-based game that was developed in the 19th century in China and has spread throughout the world since the early 20th century. It is played by four players. The game and its regional variants are widely played throughout East and Southeast Asia and have also become popular in Western countries. The game has also been adapted into a widespread online entertainment. Similar to the Western card game rummy, mahjong is a game of skill, strategy, and luck. To distinguish it from mahjong solitaire, it is sometimes referred to as mahjong rummy.

Rummy is a group of games related by the feature of matching cards of the same rank or sequence and same suit. The basic goal in any form of rummy is to build melds which can be either sets or runs and either be first to go out or to amass more points than the opposition.