Rummy is not a single, universal game; rather, it has many different variations that are influenced by culture and regional tastes. Developed injackpot slots the United States in the early 20th century, Gin Rummy is one of the most well-known varieties. Players in this two-player game must make strategic decisions & play quickly in order to form sets and runs while accumulating as few deadwood points as possible. Rummy Variations by Region.