These are the standard published rules (Bicycle Cards and pagat agree on the play; their bonus points differ from some other books, and the difference is printed below), rewritten in plain words.
What the game is
Gin Rummy is the two-player member of the Rummy family. You sort your ten cards into melds — sets of three or four of a kind, and runs of three or more in one suit — and try to be left holding as few unmatched cards (called deadwood) as possible. When your deadwood is low enough, you knock and end the hand.
Players: 2. Ages: 8 and up.
What you need: one standard 52-card deck. Aces are low only — Ace-2-3 is a run; Queen-King-Ace is not. Card points: face cards 10, Ace 1, others face value.
Setting up
- Deal 10 cards to each player, one at a time.
- The rest of the deck is the face-down stock. Turn its top card face up beside it to start the discard pile — that card is the upcard.
- The non-dealer may take the upcard. If they refuse, the dealer may take it. If both refuse, the non-dealer draws the top card of the stock, and play begins.
- The loser of a hand deals the next one.
How a turn works
- Draw either the top card of the stock or the top card of the discard pile.
- Discard one card from your hand onto the discard pile, face up. (You may not discard, on the same turn, a card you just picked up from the discard pile.)
- That is the whole turn. Melds stay in your hand in ordinary Gin — you do not lay them on the table as in basic Rummy.
- If only two cards are left in the stock and nobody has knocked, the hand is a draw: no score, and the same dealer deals again.
Knocking, gin, and scoring a hand
- Knocking: if the total value of your deadwood is 10 points or less, you may end the hand on your turn. Knock (traditionally by discarding face down), lay your hand out with the melds grouped and the deadwood separated.
- Laying off: the other player (the defender) may then add their deadwood cards onto your melds where they extend a set or run — unless you went gin (below). What is left is their true deadwood.
- Who scores: if your deadwood is lower, you score the difference between the two deadwood totals. If the defender's deadwood is equal to or lower than yours, they have undercut you — the defender scores the difference plus a bonus, even though you knocked.
- Gin: knocking with zero deadwood is going gin. You score the opponent's full deadwood total plus a gin bonus, and the defender may not lay off any cards. A gin hand can never be undercut.
- The bonuses — the books print two sets of numbers: Bicycle and pagat give a gin bonus of 20 and an undercut bonus of 10. Many other books print 25 for both. Same game, different arithmetic — agree on the numbers before the match.
- Winning the match: hands are added to a running score. The first player to 100 points wins; under the usual book rules the winner then adds a 100-point game bonus, each hand won during the match adds a box bonus, and a loser who never scored at all loses double (a shutout). At home, plenty of tables simply stop at 100 — agree the finish before you start.
Ways to play it differently
- Oklahoma Gin (labeled variant): the upcard decides how low you must go. You may knock only with deadwood equal to or less than the value of the first upcard — if it is a 4, you need 4 or fewer; if it is a face card, the usual 10 stands; if it is an Ace, you cannot knock at all — you must go gin. If the upcard is a spade, the hand scores double.
- Hollywood Gin (labeled variant — a scoring system, played with the same cards): scores are kept in three columns at once, as if three games were running side by side. Your first won hand counts in column 1 only; your second counts in columns 1 and 2; your third and every later win counts in all three. Each column is its own game to 100, and the three results are settled together at the end.
- Straight Gin (labeled variant): knocking is not allowed at all. Every hand is played out until someone goes gin (or the stock runs down to two cards).
- Big Gin (labeled variant): if the card you draw lets all eleven cards in your hand form melds, you may declare Big Gin without discarding. It pays a bigger bonus — 31 points in the usual printing — plus the opponent's deadwood, and the opponent may not lay off.
Official rule or house rule?
Can I knock with exactly 10 points of deadwood? Yes — official. Ten or fewer is legal everywhere; the risk is being undercut by a defender holding the same or less.
Ace in a run above the King (Queen-King-Ace): Not allowed in the standard game. Aces are low only, in Bicycle, pagat, and every standard printing. (One named variant, Tedesco Gin, allows "round the corner" runs — a different game, not a house tweak.)
Must the non-dealer get first chance at the upcard? Yes — official. The dealer gets a turn at it only after the non-dealer passes.
Playing with three or four people: House adaptations exist — players rotate sitting out, or play in rotating pairs. The published game is a two-player game; anything bigger is a local arrangement, not a book rule.
Common questions
Can a meld contain a card I also count as deadwood?
No. Each card is either in one meld or in your deadwood — never both, and a card may be used in only one meld.
If I knock with 1 point, can I still be undercut?
Yes — if the defender, after laying off, has 1 point or 0, the defender wins the hand. Only gin is safe from undercut.
What if the defender lays off everything and ends with zero?
Then the defender has undercut you (zero is less than any knock), and scores the difference plus the undercut bonus.
Do face cards in deadwood really count 10?
Yes. Kings, Queens, and Jacks are 10 points each in deadwood; that is why knocks are built on small cards.
Sources: Bicycle Cards, "Gin Rummy" (bicyclecards.com/how-to-play/gin-rummy), and pagat.com (John McLeod), "Gin Rummy" — rules and scoring. Variant details (Oklahoma, Hollywood, Big Gin) as recorded on pagat and in the game's Wikipedia history, each labeled above. Read in full and rewritten in our own plain words.