Gin is a two-player card game that involves drawing and discarding in play to achieve the most runs and sets possible from your hand, which consists of 10 cards. The game is won when the maximum score is reached or when a player knocks his opponent by having runs and or sets in his hand and no remaining cards (known as "going gin") or remaining cards that total 10 points or less.
Gin, the modern day version of which is called Gin Rummy, is a descendant of an 18th century variation of poker, then referred to as Gin Poker or Whiskey Poker since players would bid for drinks. It was popularized in the United States in the early-to-mid 20th century and quickly became a popular pastime of stage and movie actors. It grew to become popular among America's mass culture after being featured in many popular films. Many credit the popularization of the game to Elwood Baker.
Elwood Baker was a member of the Knickerbocker Whist Club. The Knickerbocker Whist Club was a member's only card club in New York. Some dispute Baker's role in actually creating Gin, maintaining its similarity to a simpler 19th century Mexican card came called Conquian. It is suggested that he merely reworked Conquian, rather than being the originator of Gin. The history of cards, in general, however seems to be one of reinvention and so the debate about Baker's originality may be an unnecessary one. What usually does pull consensus is that Baker did create the scoring system that made it easier for Gin to be a gambling game that could involve money prizes instead of just drinks.
Whiskey Poker is believed to be credited for the discarding element of Gin (when a player draws a card from the draw pile and chooses to use it to create a set or run then discard another card or discard the drawn card). In Whiskey Poker each player has five cards and a "widow" pile from which each player can draw cards. The "widow" pile is similar to the discard pile in modern Gin.
Today's Gin, likely got its name in the same fashion that Gin Poker and Whiskey Poker did. Whiskey Poker and Gin Poker were named so because whiskey and gin were the respective prize drinks for winning each game which was popular among gamblers in saloons. Some suggest, however, that modern Gin, or Gin Rummy, got its name from the son of the aforementioned Elwood Baker, who purportedly named the gamed allegedly created by his father after his two favorite drinks, gin and rum.
While the popularity of Gin has come and gone over the past hundred or so years since it was introduced, today it is again a popular pastime of America's card playing enthusiasts and has gained popularity with the advent of computer software and online gaming that allows anyone with access to learn and play the game. In addition, Gin is a popular game in the professional card tournament circuit.