Game foundations for rummy. Many contemporary variations of rummy are based on the original games. The most well-known type is Gin Rummy, yono sbi app apkwhich first appeared in the United States in the early 20th century and immediately became well-liked. Gin Rummy is a game where two players compete to form runs & sets from their hands while attempting to "knock" when they think their opponent has more points than they do.