Early in the 20th century, rummy became a mainstay in American homes as it developed further. Since the game was frequently played in casual settinbsky tmsgs, players developed a sense of camaraderie & friendly rivalry. When the standard 52-card deck was introduced, gameplay became even more simplified and more widely available. Rummy was a popular past time by the 1930s, and regional variations like Indian and Gin Rummy were starting to appear.