Gin Rummy Card Game Rules: How to Knock, Score and Win

The short version: Gin rummy is a two-player card game where you build sets and runs from a ten-card hand, discard your unmatched cards, and knock once your unmatched "deadwood" adds up to 10 points or less. You score by counting your opponent's leftover deadwood, with bonus points for going gin (zero deadwood) or catching a bad knock. First player to 100 points wins the game.

I learned this game from my late father, who played it every single evening with a neighbour for decades and never once wrote the rules down because he didn't need to. Most online explanations of gin rummy are technically correct and completely useless for someone who wants to play a hand tonight. So here's the version with the numbers that matter, a worked example, and the one bit of strategy advice most guides get backwards.

What you need and how a hand starts

You need a standard 52 card deck, no jokers, and one other person. Each player is dealt 10 cards. The rest of the deck sits face down as the stock, and the top card is turned face up next to it to start the discard pile.

• Non-dealer goes first and can either take the face-up discard or refuse it and draw from the stock.
• Every turn from then on is the same shape: draw one card (from stock or the top of the discard pile), then discard one card face up.
• The goal is to arrange your 10 cards into melds: sets (three or four cards of the same rank, like 7-7-7) or runs (three or more cards in sequence in the same suit, like 4-5-6 of hearts).
• Any card that doesn't fit into a meld is deadwood, and each deadwood card carries a point value: number cards are worth their face value, face cards (jack, queen, king) are worth 10, and aces are worth 1.

How to knock

Once your deadwood total is 10 points or less, you're allowed to knock instead of discarding on your turn. You lay your cards face up, split into melds and deadwood, and your opponent then lays their cards down too, splitting theirs into melds and deadwood.

Here's the part that trips people up: your opponent gets to "lay off" any deadwood cards of theirs that extend your melds. Say you knock with a run of 5-6-7 of clubs as one of your melds. If your opponent is holding the 8 of clubs as deadwood, they can add it onto your run, and it no longer counts against them.

If your own deadwood hits exactly zero, you don't knock, you go gin. Going gin means you lay down all 10 cards as complete melds with nothing left over, and your opponent isn't allowed to lay off anything onto your melds at all. This is the strongest possible result in a single hand.

Scoring, step by step

Scoring is where most rule pages get vague, so here's the exact sequence.

• If you knock (not gin): add up your deadwood total, then add up your opponent's deadwood total after they've laid off whatever they can. Subtract your number from theirs. If theirs is higher, you score the difference.
• If you go gin: you score your opponent's full deadwood total (no lay-offs allowed) plus a 25-point gin bonus.
• The undercut: if your opponent's deadwood after laying off is equal to or lower than yours, they've "undercut" you. They score the difference (which could be zero) plus a 25-point undercut bonus, and in most house rules they also get to deal the next hand instead of you.

Play continues, hand after hand, with scores accumulating. The first player to reach 100 points wins the game. Winning also earns a 100-point game bonus, and in most scoring sheets you add 20 points for every hand you won during that game, even the ones you didn't need. This is sometimes called the "box bonus," and it's why a player who wins the game 105 to 40 can end up with a final score well over 300 once the boxes and bonuses are tallied.

A worked hand, so you can see the maths

Say you're playing a casual game with a friend after dinner. You're dealt a decent hand and after a few turns you've built:

• A run: 4-5-6 of spades
• A set: 9-9-9 (clubs, hearts, diamonds)
• Deadwood: king of hearts (10 points), 3 of clubs (3 points), 2 of diamonds (2 points)

Your deadwood adds up to 15, which is too high to knock. You discard the king, draw a fresh card, and a couple of turns later you've drawn the 4 of clubs, letting you drop the 3 and the 2 and reduce your deadwood to zero: you go gin.

Your opponent, meanwhile, has 34 points of deadwood sitting in their hand because they were one card away from a run. Since you went gin, they don't get to lay anything off. You score their full 34 points plus the 25-point gin bonus, for 59 points in that single hand. That's more than half the game in one go, which is exactly why going for gin is often worth the risk of holding on a turn or two longer than feels comfortable.

The strategy point most guides get wrong

Nearly every beginner's guide tells you to knock the moment you're allowed to, because "why wait." I'd push back on that, and it's the bit that separates people who win consistently from people who win occasionally.

Knocking early with, say, 8 or 9 points of deadwood exposes you to the undercut. Your opponent only needs to be sitting on equal or lower deadwood after laying off, and suddenly they've taken the hand, the 25-point bonus, and the deal. In a two-hander where you're watching what your opponent draws and discards, you often have a decent read on whether they're close to their own knock. If they've been discarding high cards and picking up from the stock rather than the discard pile, they're probably still assembling their hand, not sitting pretty. That's your signal to hold out for gin rather than knock the second you technically can.

The uncomfortable truth is that gin rummy rewards patience and information reading far more than it rewards speed, and most "how to win" articles skip straight past that because knocking fast feels like the more exciting tip to give.

Reading the discard pile

The single biggest tell in gin rummy is what your opponent doesn't pick up. If they let a 7 of hearts sit on top of the discard pile for two turns without taking it, they're probably not collecting hearts around that number, which tells you it's safer to discard nearby heart cards yourself. Conversely, if they suddenly start drawing from the discard pile instead of the stock, they've found a card that fits something, and it's worth tightening up what you throw away in that suit and rank range.

This is also why holding onto high-value cards "just in case" is usually a mistake. A lone king or queen sitting in your hand as deadwood is 10 points of risk every single hand you keep it, and if your opponent knocks unexpectedly, you're the one eating that number.

House rule variations worth knowing

• Big Gin: some groups allow you to go gin with all 11 cards forming melds if you've just drawn your 11th card before discarding, which scores an extra 31 points instead of the standard 25.
• Hollywood scoring: played across three separate scoring columns at once for multiple simultaneous games, popular with people who play for stakes over several rounds in one sitting.
• Knock limit variations: some house rules lower the knock threshold to 7 or even ban knocking altogether below a set number of deadwood points, which pushes the game further toward "everyone waits for gin."

None of these change the core mechanics above, they just adjust the risk and reward slightly. Agree the variant before you deal the first hand, because arguing about it mid-game is how good friendships end over a deck of cards.

Frequently asked questions

What is the maximum deadwood you can have to knock in gin rummy?

In standard rules you can knock with 10 points of deadwood or less. Some house rules lower this to 7, so it's worth agreeing the threshold before you start playing.

What happens if my opponent undercuts my knock?

If your opponent's deadwood, after laying off cards onto your melds, is equal to or lower than yours, they undercut you. They score the point difference plus a 25-point bonus, and in most versions they also deal the next hand.

How many points do you need to win a game of gin rummy?

Standard play goes to 100 points across as many hands as it takes. The winner then adds a 100-point game bonus plus 20 points for every hand they won during that game.

Is going gin always better than knocking early?

Not always, but often. Going gin scores your opponent's full deadwood with no lay-offs allowed and adds a 25-point bonus, while knocking early risks an undercut if your opponent's hand is closer to complete than you think.