Draw, discard, and shape your hand into sets and runs, then knock at the right moment to leave your opponent stuck with deadwood.
Each turn you take one card from the face-down stock or the top of the discard pile, then discard one card. Build sets of three or four of a kind and runs of three or more cards in the same suit. When your unmatched cards (deadwood) total 10 or less, you may knock to lay down and score the difference.
Gin rummy was created in 1909 by Elwood T. Baker and his son C. Graham Baker, and it stayed a New York game for three decades. What changed was Hollywood: the game became a fad there in 1941 and spread across the country behind it.
The scale of that spread is easy to understate. A 1947 survey by American playing-card manufacturers concluded that the number of people who learned gin rummy during the Second World War equalled the number who learned pinochle, cribbage, poker and bridge combined.
Its ancestry is disputed. The magician John Scarne argued it evolved from 19th-century whiskey poker; the card historian David Parlett calls that "highly implausible" and points instead to Conquian, the older rummy game that most of the family descends from.
Gin rummy is a traditional two-player card game of melding and timing. This is an original, free browser version with a daily deal and a knocking AI opponent, no download or sign-up needed.