Blackjack guide
How to play blackjack, explained.
Blackjack, sometimes called twenty-one, is the casino card game where your decisions really do affect the result. This guide covers the rules, what each option means, basic strategy, the house edge and the rule changes that quietly make a table better or worse.
The basics
How a hand works
You play against the dealer, not the other players. The aim is to finish closer to 21 than the dealer without going over.
Place your bet
Put your stake down before any cards are dealt. Each table shows a minimum and maximum bet.
The deal
You get two cards face up. The dealer gets one card face up and one face down, called the hole card. Some games deal the dealer's second card later.
Your decisions
You choose to hit, stand, double, split or surrender, depending on your cards and the dealer's up card. If you go over 21, you bust and lose straight away.
The dealer plays
The dealer reveals the hole card and draws by fixed rules, with no choices. If the dealer busts, every hand still in play wins.
Card values
| Card | Value | Note |
|---|---|---|
| 2 to 9 | Face value | A 7 is worth 7 |
| 10, J, Q, K | 10 | Suits don't matter |
| Ace | 1 or 11 | Counts as 11 unless that would take you over 21 |
A hand with an ace counted as 11 is a "soft" hand, because it can't bust with one more card. A 6 and an ace is soft 17. A hand with no ace, or an ace that must count as 1, is "hard".
Your options
Hit, stand, double, split and more
An ace and any ten-value card as your first two cards is a blackjack, or natural. It usually pays 3:2 and beats any other 21.
Hit
Take another card. You can keep hitting until you stand or bust.
Stand
Keep your total and end your turn. The dealer then plays their hand.
Double down
Double your stake on your first two cards and take exactly one more card. It's strongest on totals of 10 or 11.
Split
If your first two cards are a pair, add a second equal stake and play them as two separate hands. Split aces usually get only one card each.
Insurance
Offered when the dealer shows an ace. It's a side bet of up to half your stake that pays 2:1 if the dealer has blackjack. Over time it's a losing bet for basic-strategy players.
Surrender
Where allowed, give up your hand after the first two cards and get half your stake back. Useful only in a few very weak spots, such as hard 16 against a dealer 10.
How the dealer plays
| Dealer total | Dealer must |
|---|---|
| 16 or less | Hit |
| Hard 17 or more | Stand |
| Soft 17 (S17 tables) | Stand |
| Soft 17 (H17 tables) | Hit |
The rule is printed on the table or in the game's help screen, usually as "Dealer stands on soft 17" or "Dealer hits soft 17". Standing is better for the player.
Basic strategy
The maths-based way to play each hand
Basic strategy is the best decision for every combination of your hand and the dealer's up card, worked out by computer over millions of hands. It doesn't guarantee a win, but it keeps the house edge as low as the rules allow.
| Your hand | Dealer shows 2 to 6 | Dealer shows 7 to ace |
|---|---|---|
| Hard 17 or more | Stand | Stand |
| Hard 13 to 16 | Stand | Hit |
| Hard 12 | Stand on 4 to 6, hit on 2 or 3 | Hit |
| Hard 11 | Double | Double against 7 to 10, hit against an ace |
| Hard 10 | Double | Double against 7 to 9, hit against 10 or ace |
| Hard 9 | Double on 3 to 6, hit on 2 | Hit |
| Hard 8 or less | Hit | Hit |
| Soft 19 or more | Stand | Stand |
| Soft 18 | Double on 3 to 6, stand on 2 | Stand on 7 or 8, hit on 9, 10 or ace |
| Soft 13 to 17 | Double on 5 or 6 (soft 15 and 16 also on 4, soft 17 also on 3 and 4), otherwise hit | Hit |
| Pair of aces or 8s | Split | Split |
| Pair of 10s | Stand | Stand |
| Pair of 5s | Treat as hard 10 | Treat as hard 10 |
| Pair of 9s | Split | Split against 8 or 9, stand against 7, 10 or ace |
| Pair of 2s, 3s, 6s or 7s | Split | Split 2s, 3s and 7s against 7, otherwise hit |
| Pair of 4s | Split on 5 or 6, otherwise hit | Hit |
A simplified summary for multi-deck games where the dealer stands on soft 17 and you can double after splitting. Small details change with the rules, so check a chart made for the exact game. If doubling isn't allowed, hit instead (stand on soft 18). Insurance is never part of basic strategy.
The numbers that matter
House edge and the rules that change it
With good rules and basic strategy, the house edge is typically around 0.5%. That means the casino keeps about half a unit for every 100 units staked, on average over a very long run. Played by guesswork, the edge is much higher.
| Rule | Better for you | Worse for you | Rough effect |
|---|---|---|---|
| Blackjack payout | 3:2 (a 10-unit bet wins 15) | 6:5 (a 10-unit bet wins 12) | 6:5 adds about 1.4% to the edge, the biggest single change |
| Soft 17 | Dealer stands (S17) | Dealer hits (H17) | H17 adds about 0.2% |
| Number of decks | Fewer decks | More decks (6 to 8) | Single deck versus eight decks is worth roughly half a percent |
| Doubling | On any first two cards, and after splits | Only on 9, 10 or 11, or not after splits | Small, but it adds up |
| Surrender | Offered | Not offered | Small gain if used correctly |
Figures are approximate and interact with each other. A single-deck game that pays 6:5 is usually worse than an eight-deck game that pays 3:2. The rules are listed in the game's help screen.
Online blackjack
Card counting, side bets, live and RNG games
Why card counting doesn't work online
Counting relies on tracking cards as they leave a shoe that isn't reshuffled for a while. Digital (RNG) blackjack reshuffles the virtual deck before every hand, so there's nothing to track. Live games usually use six or eight decks and reshuffle well before the end of the shoe, which makes any advantage tiny.
Side bets
Extra bets on things like your first two cards making a pair, or a poker-style hand with the dealer's up card. They can pay big multiples, but they carry a much higher house edge than the main game, often several percent or more.
RNG blackjack
Played against software, with results from a random number generator. It's fast, you set the pace, and low minimum bets are common. Speed matters: more hands an hour means more staked.
Live blackjack
A real dealer and real cards, streamed from a studio. It plays more slowly, and some tables let unlimited players share the same starting hand. See our live casino guide for how these games work.
Bonuses and blackjack
Casino bonuses often count blackjack at a low rate towards wagering, or exclude it. Read the terms first, and see our guide to wagering requirements.
Before you play
Playing sensibly
A low house edge still means losing over time. Good strategy makes your money last longer; it doesn't turn blackjack into income.
- Set a budget before you start and treat it as the cost of entertainment. Only use money you can afford to lose.
- Check the rules first: the blackjack payout, the soft 17 rule and the number of decks.
- Keep a strategy chart open for the game you're playing. Many sites allow it, and it removes guesswork.
- Skip insurance and treat side bets as extras, not part of your plan.
- Watch your pace. At 10 units a hand and 200 hands an hour, you're staking 2,000 units an hour.
- Use deposit limits, session reminders and time-outs. Most sites offer them in your account settings.
- Stop when you planned to, win or lose. Doubling your bet after losses doesn't change the edge.
Good to know
Blackjack FAQ
What is the house edge in blackjack?
With good rules and perfect basic strategy, it's typically around 0.5%. It rises with worse rules, such as a 6:5 payout on blackjack or the dealer hitting soft 17, and it's much higher if you play by guesswork.
Should I take insurance?
Not if you're playing basic strategy. Insurance is a side bet that the dealer has blackjack, and it pays 2:1 when the true odds are worse than that, so it loses money over time.
Can you count cards in online blackjack?
Not in a useful way. RNG blackjack reshuffles the virtual deck before every hand, and live games usually use six or eight decks with an early reshuffle, so any edge from counting is tiny or zero.
What does "dealer stands on soft 17" mean?
Soft 17 is a total of 17 that includes an ace counted as 11, such as an ace and a 6. If the dealer stands on it, the game is slightly better for you than one where the dealer must hit it.
What is the difference between 3:2 and 6:5 blackjack?
It's how much a natural blackjack pays. At 3:2, a 10-unit bet wins 15. At 6:5, it wins only 12. The 6:5 payout adds roughly 1.4% to the house edge, which is more than most other rule changes combined.
Check the rules where you live. Whether online blackjack and other casino games are legal, and which sites you can use, depends on local laws and each operator's own terms. This guide is general information only and isn't a recommendation. 18+ only. If gambling stops being fun, see our responsible gambling page.