Gin Rummy · Complete guide
Gin Rummy: how to play, and when to knock
Ten cards, two piles and one decision every hand: cash a small win now, or hold out for gin and risk the undercut.
Gin Rummy is a two-player game of ten cards, one draw and one discard per turn. You build sets of equal ranks and runs in a suit; everything left over is deadwood, and the hand ends when you knock with ten points of deadwood or less.
It has an unusually precise origin for a card game: it was devised in 1909 in New York by Elwood T. Baker, a whist teacher, from the older game of straight rummy. His two changes made the modern game — melds stay hidden until the hand ends, and you may knock early instead of waiting for a complete hand.
Those two rules create the whole tension. Because melds are hidden, you must infer your opponent's hand from what they take and throw. Because you can knock early, every hand contains a timing decision: a small certain score now, or a bigger one later with the risk of being undercut — losing the hand to the player you were about to beat.
It became famous in 1930s and 1940s Hollywood, where short hands that could be interrupted at any moment suited film sets perfectly. It has been the standard two-handed card game in America ever since.
How to play
Ten cards, sets and runs, and the three ways a hand ends: knock, gin or undercut. Plus lay-offs, scoring to 100 with box bonuses, and the Oklahoma variant.
Where it comes from
From a nineteenth-century Mexican melding game to a 1909 New York invention with a credited designer — and the card game Hollywood played between takes.
- All rummy games descend from draw-and-discard melding games, documented earliest as Conquian.
- Gin Rummy was devised in 1909 in New York by Elwood T. Baker, a whist teacher.
- Its two innovations were hidden melds and the ability to knock before completing a hand.
- The game boomed in 1930s and 1940s Hollywood, where short hands suited film sets.
How to win
Why middle cards beat high ones, how to read your opponent from their draws, which discards are actually safe, and the knock-or-wait decision that decides most matches.
- Throw high cards early and keep flexible middle cards, which can form more melds.
- Draw from the stock by default — taking from the discard pile tells your opponent what you hold.
- Track what they pick up: never throw a card adjacent in suit or matching in rank.
- Knock early with low deadwood; knocking on exactly ten invites an undercut.
Common questions
What is deadwood?
Any card not part of a set or a run. Aces count 1, court cards 10 and the rest their face value. You may knock when your deadwood totals ten or less.
What is an undercut?
When the knocker's deadwood is equal to or greater than their opponent's after lay-offs. The defender scores the difference plus a 25-point bonus.
Should I knock as soon as I can?
Usually yes — a small certain score beats a bigger risky one. The exception is knocking on exactly ten, where the undercut risk is real.
Should I take from the discard pile?
Only when it completes a meld or is a major improvement. Every pick-up tells your opponent what you are building.
Can aces be high in a run?
No. In standard Gin Rummy the ace is low and runs do not turn the corner, so Q-K-A is not a valid run.
Guides
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