Gin Rummy Scoring Explained: Knocks, Gins, and Undercuts

Gin rummy is the great American two-player game — quick to deal, slow to master, and famously easy to argue about at the exact moment somebody knocks. Was that an undercut? Is gin twenty-five or twenty? Who writes down what? The play itself takes five minutes to learn; the scoring is where every family invents its own weather.

This page settles it: card values, knocking, undercuts, gin and big gin, boxes, and the race to 100 — with worked examples and an honest section on the numbers that vary from table to table. Keep it open, or print the free score sheet and cheat sheet and argue never again.

How a hand works, in 30 seconds

Two players, a standard 52-card deck, ten cards each. On your turn you draw one card — from the stock or the discard pile — and discard one. You’re building melds:

• a set — three or four cards of the same rank (7♠ 7♥ 7♦), or
• a run — three or more consecutive cards of one suit (4♣ 5♣ 6♣).

No card can belong to two melds at once. Whatever isn’t melded is your deadwood, and deadwood is what the whole scoring system revolves around: yours hurts you, your opponent’s feeds you.

Card values and deadwood

Card	Deadwood value
Ace	1
2 through 10	Face value
Jack, Queen, King	10 each

Two details worth engraving on the table: the ace is low only — A-2-3 is a run, Q-K-A is not — and face cards are the heaviest deadwood in the game, which is why experienced players shed idle kings and queens early.

Knocking

When your deadwood totals 10 points or less, you may end the hand on your turn: discard one card face down — the traditional knock — and spread your melds. Ten exactly qualifies. Then:

1. Your opponent spreads their melds.
2. Your opponent may lay off unmatched cards onto your melds — adding a fourth 7 to your set, extending your 4-5-6 with the 3 or the 7 of that suit. Every card laid off leaves their deadwood.
3. Compare deadwood. If yours is lower, you score the difference.

The undercut

If, after laying off, the defender’s deadwood is equal to or lower than the knocker’s, the hand flips: the defender scores the difference plus a 10-point bonus (classic scoring — many tables play 20 or 25; see house numbers). Yes, a tie counts as an undercut. Yes, knocking with 9 and losing the hand anyway builds character.

Gin (and big gin)

Meld all ten cards — zero deadwood — and you’ve gone gin: discard your last unmatched card face down and show the hand. You score your opponent’s entire deadwood plus a 20-point bonus (25 at many tables). Two iron rules protect it:

• No lay-offs against gin. The defender’s stuck cards all count.
• Gin cannot be undercut. The bonus always stands.

Big gin is a popular modern addition rather than part of the classic rules: if the card you just drew gives you eleven melded cards, you declare it with no discard at all, for a bigger bonus — commonly 31 (some tables, 50). If your crowd learned gin from a phone app, they probably expect big gin; decide before the first deal.

Three hands scored step by step

Example 1 — a clean knock

You knock with 4 deadwood. Your opponent spreads 23 deadwood, then lays an 8♥ off onto your 5-6-7♥ run, dropping to 15.

You score 15 − 4 = 11 points.

Example 2 — the undercut

You knock with 9. Your opponent lays off two cards and lands on 7 — lower than your 9.

Your opponent scores (9 − 7) + 10 = 12 points. You knocked, they cashed. That’s gin rummy.

Example 3 — gin

You go gin. Your opponent is caught holding K♠ Q♦ J♣ A♥ — 31 deadwood, and no lay-offs allowed.

You score 31 + 20 = 51 points. One hand, half the game.

Scoring the game: boxes and bonuses

Hands accumulate on the score sheet until someone reaches 100 points. Then the bookkeeping pays out:

At game end	Points
Game bonus — to the player who reached 100	100
Shutout — if the loser never scored a hand	bonus doubles to 200
Box bonus — per hand won, each player	20

A finished game, worked through — you won three hands (the 11, the 51, and a later 38-point gin), your opponent won one undercut worth 12:

	You	Opponent
Hand scores	11 + 51 + 38 = 100	12
Game bonus	100	—
Boxes (20 per hand won)	3 × 20 = 60	1 × 20 = 20
Final	260	32

Playing a series? Track the margin (here, 228) or simply tally games won — our printable score sheet has columns for hands, running totals, and the end-of-game reckoning, so nobody has to reconstruct it from napkin arithmetic.

When nobody knocks: the two-card rule

If the stock runs down to two cards and the player who took the third-to-last card discards without knocking, the hand is cancelled — no score for anyone, and the same dealer deals again. Rare, memorable, and always somebody’s fault.

House numbers and named variants

The mechanics of gin rummy are remarkably stable; the numbers travel. The two honest columns:

Bonus	Classic	Common at many tables & apps
Gin	20	25
Undercut	10	20–25
Box (per hand won)	20	25
Big gin	— (not played)	31 (sometimes 50)

Neither column is “wrong.” This site’s guides and printable sheets use the classic set; whichever you choose, say it out loud before the first deal and write it at the top of the score sheet.

• Oklahoma gin: the first upcard sets the knock limit for the hand — turn a 6, and knocking needs 6 or less. An ace means gin only. In many circles a spade upcard doubles the hand’s score.
• Hollywood: bookkeeping bravado — three games scored at once on a triple-column sheet. Wonderful fun, bring a sharp pencil.

Frequently asked questions

How many points do I need to knock?

Deadwood of 10 or less — 10 exactly is legal. Zero deadwood isn’t a knock at all; that’s gin, and it pays better.

What if my opponent ends up with fewer points than me after I knock?

That’s the undercut: they score the difference plus the bonus (10 classic, 20–25 at many tables). Equal counts also go to the defender. It’s the tax on greedy knocking.

Can gin be undercut?

No. No lay-offs are allowed against gin and no undercut is possible — the gin bonus always stands.

What is big gin worth?

Commonly 31 points, sometimes 50 — but it’s a modern add-on, not classic law. Agree on it (or skip it) before you deal.

Is the ace high or low?

Low only: A-2-3 works, Q-K-A doesn’t. At 1 point, the ace is also the gentlest deadwood in the game.

How many points wins the game?

First to 100 ends it. Then add the 100-point game bonus (200 on a shutout) and 20 per hand won for each player, and compare totals.

Two chairs, one deck

If counting the hand is your favorite part, gin’s sibling obsession is cribbage scoring — same arithmetic pleasure, more pegs. For a longer two-player evening, deal into canasta for two. Hosting more than two? The card game night guide seats everybody — and when the table won’t fill at all, you can still play with real people online, free and friendly.