How to Play 21: Rules, Card Values & Examples

The goal of 21

21 — known in casinos as blackjack — is a game between you and the dealer. Other players at the table do not matter. You win by finishing with a hand closer to 21 than the dealer's, or by staying in while the dealer goes over.

Go over 21 yourself and you bust: your bet is lost immediately, even if the dealer busts afterwards. That one rule is where the house gets its edge — you always act first.

21 goes back at least to 17th-century Spain, where it was called veinte y uno. Casinos today deal many versions of it — from European Blackjack to Blackjack Switch — but they all start from the rules on this page. Compare them in our guide to blackjack games.

King of Diamonds — Your 19 beats the dealer's 17. You win the hand and are paid even money.

9 of Spades — Your 19 beats the dealer's 17. You win the hand and are paid even money.

Card values

Suits do not matter in 21. Only the rank of each card counts:

Cards	Worth
	Their number: 2 to 10
	10 each (Jack, Queen, King)
	1 or 11 — whichever helps the hand

Because an Ace can switch between 1 and 11, a hand holding an Ace counted as 11 is called soft: you can take another card without any risk of busting. A hand without that flexibility is hard.

Ace of Hearts — Soft 17Ace counts 11. Another card cannot bust you.

6 of Spades — Soft 17Ace counts 11. Another card cannot bust you.

10 of Clubs — 16No Ace. Any card over 5 busts you.

6 of Diamonds — 16No Ace. Any card over 5 busts you.

Ace of Spades — BlackjackAce plus a ten-card: the best hand in the game.

King of Hearts — BlackjackAce plus a ten-card: the best hand in the game.

How a round works

Place your bet. Chips go in the betting circle before any cards are dealt.
The deal. Every player gets two cards face up. The dealer gets one face up — the up-card — and one face down, the hole card.
Blackjacks are settled. If the dealer's up-card is an Ace or a ten they check for blackjack. A player blackjack is paid at once unless the dealer has one too.
You play your hand. Starting from the dealer's left, each player hits, stands, doubles or splits until they stand or bust.
The dealer plays. The hole card is turned over and the dealer draws by fixed rules.
Bets are paid. Higher total wins; equal totals are a push and the bet is returned.

Your options: hit, stand, double, split

Hit

Take another card. You can hit as many times as you like until you stand or bust. At the table you tap the felt.

9 of Hearts — Hard 12 against a dealer 10: too weak to stand on, so you **hit**. Check it in the calculator

3 of Clubs — Hard 12 against a dealer 10: too weak to stand on, so you **hit**. Check it in the calculator

Stand

Keep what you have and end your turn. Wave your hand flat over your cards.

10 of Diamonds — Hard 13 against a 6: **stand** and let the dealer take the risk of busting. Check it in the calculator

3 of Spades — Hard 13 against a 6: **stand** and let the dealer take the risk of busting. Check it in the calculator

Double down

Double your bet in exchange for exactly one more card. It is the strongest move in the game when used on the right hands — usually a total of 10 or 11 against a weak dealer card.

6 of Clubs — Hard 11 against a 6: **double down**. Any ten-value card gives you 21. Check it in the calculator

5 of Diamonds — Hard 11 against a 6: **double down**. Any ten-value card gives you 21. Check it in the calculator

Split

When your first two cards are a pair, you can split them into two separate hands, putting up a second bet equal to the first. Each hand then gets a new second card.

8 of Spades — A pair of 8s: always **split**. Hard 16 is the worst total in the game; two hands starting at 8 are far better. Check it in the calculator

8 of Hearts — A pair of 8s: always **split**. Hard 16 is the worst total in the game; two hands starting at 8 are far better. Check it in the calculator

Surrender and insurance

Some tables let you surrender a bad hand straight after the deal and get half your bet back — worth doing with hard 16 against a 9, 10 or Ace. When the dealer shows an Ace you will also be offered insurance, a side bet that the dealer has blackjack. Decline it: it is one of the worst bets on the table.

Not sure which move is right? The basic strategy chart answers every combination, and the strategy calculator explains the reason for any single hand.

How the dealer plays

The dealer has no decisions to make. They follow the house rule printed on the table:

16 or less: the dealer must hit.
17 or more: the dealer must stand.
Soft 17: depends on the table — "Dealer stands on all 17s" (S17) is better for you than "Dealer hits soft 17" (H17).

10 of Spades — The dealer turned over a 10 for 16, had to hit, and drew a 9. Dealer busts with 25 — your 18 wins.

8 of Diamonds — The dealer turned over a 10 for 16, had to hit, and drew a 9. Dealer busts with 25 — your 18 wins.

Because the dealer must keep hitting to 17, weak up-cards (2 to 6) often end in a bust. That is why you stand on modest totals against them and play aggressively against strong ones.

Winning, losing and payouts

Result	You receive
You win	1 to 1 — bet $10, win $10
Blackjack (Ace + ten-card)	3 to 2 — bet $10, win $15
Push (same total)	Your bet back
You bust or the dealer is higher	You lose your bet
Surrender	Half your bet back

Beginner mistakes to avoid

Copying the dealer. Hitting until 17 regardless of the dealer's card is a well-known losing strategy.
Never busting. Standing on 12–16 against a 7 or higher gives up many hands you could have won.
Standing on soft 17. An Ace and a six can never bust with one more card. Hit it, or double against a weak dealer.
Splitting tens. A 20 is already a winning hand — keep it.
Taking insurance or "even money". Both lose over time unless you are counting cards.

Ready to try it? Deal a few hands in the free blackjack game, then learn the full set of correct decisions in the basic strategy trainer. Playing with friends instead? Read how to play 21 with a deck of cards at home.

Play blackjack freeDeal real hands against the dealer and practise every rule on this page.

Frequently asked questions

Is 21 the same game as blackjack?

Yes. 21 is the everyday name for blackjack. The casino game, the one you play online and the one played at home with a deck of cards all follow the same core rules: beat the dealer by getting closer to 21 without going over.

What is an Ace worth in 21?

An Ace counts as 1 or 11, whichever is better for the hand. A hand where the Ace can still count as 11 without busting is called a soft hand.

What happens if you and the dealer both have 21?

It is a tie, called a push, and you get your bet back. The exception is a natural blackjack: an Ace and a ten-value card on the first two cards beats a 21 made with three or more cards.

Does the dealer have to hit on 16?

Yes. The dealer has no choices: they must hit on 16 or less and stand on 17 or more. Some tables make the dealer hit a soft 17 as well — the table felt will say which.

How many decks are used in 21?

Anything from one to eight. Casinos most often use six or eight decks in a shoe; home games normally use a single deck.

Sources

Rules and figures in this article are taken from Wikipedia:

Blackjack — Wikipedia
Twenty-one (card game) — Wikipedia
Blackjack — Rule variations and effects on house edge — Wikipedia

Practise it on 21Count

Play blackjack freeDeal real hands against the dealer, with a live running count you can switch on. Basic strategy chartThe full hit, stand, double and split chart for hard hands, soft hands and pairs. Strategy calculatorEnter any hand and dealer up-card to get the correct play and the reason for it. Blackjack tutorialSix chapters from the basics to counting and bankroll management.

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