It came from the Mexican game "Concentration," according to some historians, but it also has ties to the Chinese game "Kong," according to others. Whatever its origins, rummy has slots of cashspread throughout the world as a common card game, with many variations appearing over time. The basic mechanics of the game, which haven't changed over time, involve creating sets and sequences. Rummy evolved into various variations, including Gin Rummy, Indian Rummy, and Kalooki, as it spread throughout the world and adjusted to local tastes and customs.