Why does blackjack have a reputation as the “best” casino game? Because it is the one table game where your decisions genuinely change the maths. Play on instinct and the house edge can run to several per cent. Follow basic strategy on a standard six-deck table and it drops to roughly 0.5%. That is not a system or a trick. It is simply the best decision for every combination of your hand and the dealer’s upcard, worked out by computer over millions of hands.
What does basic strategy assume?
The charts below are for the most common online rules: six or eight decks, dealer stands on soft 17, double after split allowed, and blackjack paying 3 to 2. If your table uses different rules, a few marginal decisions change, which we flag where it matters. Check the game’s help panel before you play; licensed UK casinos must display the rules for each game.
One point before the charts: basic strategy lowers the house edge, it does not remove it. Over time the casino still wins. The aim is to get the most entertainment for your money, not to beat the game.
Hard totals: what should you do?
A hard total is any hand without an ace, or with an ace that has to count as 1. These are the decisions you will make most often.
| Your hand | Dealer 2 to 3 | Dealer 4 to 6 | Dealer 7 to 9 | Dealer 10 or Ace |
|---|---|---|---|---|
| 8 or less | Hit | Hit | Hit | Hit |
| 9 | Hit vs 2, double vs 3 | Double | Hit | Hit |
| 10 | Double | Double | Double | Hit |
| 11 | Double | Double | Double | Double vs 10, hit vs Ace |
| 12 | Hit | Stand | Hit | Hit |
| 13 to 16 | Stand | Stand | Hit | Hit |
| 17 or more | Stand | Stand | Stand | Stand |
The logic is easy to remember once you see it. When the dealer shows 4, 5 or 6, they are likely to bust, so you stand on stiff hands and let them take the risk. When the dealer shows 7 or higher, they are likely to finish with a strong total, so you keep drawing to anything below 17. If your table offers late surrender, giving up 16 against a 9, 10 or Ace, and 15 against a 10, is better than playing them out.
Soft hands: how do aces change things?
A soft hand contains an ace counted as 11. You cannot bust by taking one more card, which is why soft hands are often doubled when the dealer is weak.
| Your hand | Double against | Otherwise |
|---|---|---|
| A,2 or A,3 | 5 and 6 | Hit |
| A,4 or A,5 | 4, 5 and 6 | Hit |
| A,6 | 3, 4, 5 and 6 | Hit |
| A,7 (soft 18) | 3, 4, 5 and 6 | Stand against 2, 7 and 8; hit against 9, 10 and Ace |
| A,8 and A,9 | Never (stand) | Stand |
Soft 18 is the hand most players misplay. Standing on 18 feels safe, but against a dealer 9, 10 or Ace it is a long-run loser compared with hitting. If you remember one soft-hand rule, make it that one.
Pairs: when should you split?
Splitting turns one hand into two, each with its own stake. Some splits attack a weak dealer; others rescue a bad starting hand.
| Pair | Split against | Otherwise |
|---|---|---|
| A,A | Always | – |
| 8,8 | Always | – |
| 10,10 | Never | Stand on 20 |
| 9,9 | 2 to 6, 8 and 9 | Stand against 7, 10 and Ace |
| 7,7 | 2 to 7 | Hit |
| 6,6 | 2 to 6 | Hit |
| 5,5 | Never | Play as hard 10 (double against 2 to 9) |
| 4,4 | 5 and 6 | Hit |
| 2,2 and 3,3 | 2 to 7 | Hit |
The splits for 4s, 2s and 3s against low cards assume you can double after splitting, which most online tables allow. Without that rule, play them more cautiously.
A worked example: one hand, three decisions
Charts are easier to trust once you have followed one through a real hand. Say you are dealt 8 and 8, and the dealer shows a 10.
- Do you split? Yes. Sixteen against a 10 is the worst position in blackjack, and the pairs chart says always split 8s. You now have two hands, each starting with an 8, and a second stake on the table.
- First hand draws a 3, making 11. The hard totals chart says double 11 against a 10, and because double after split is allowed, you do.
- Second hand draws a 6, making 14. Against a dealer 10 you hit 14, even though it feels risky. Standing would leave you relying on the dealer to bust, which they will do far less often with a 10 showing.
None of those choices guarantees a win on this hand. What they do is lose less, on average, than any alternative over thousands of hands. That is the only promise basic strategy makes, and it keeps it.
How do you learn the charts?
Most people find it easiest in three stages. Learn the hard totals first, since they come up most often. Add the pair splits next, because the “always” and “never” rules (always split aces and 8s, never split 10s and 5s) are quick wins. Leave soft hands until last. Many licensed casinos offer free-to-play versions of their blackjack games, which you can use for practice once your age has been verified, as UK rules have required since May 2019. Keep the chart open on screen while you play; nobody at an online table minds.
Which table rules matter most?
Two blackjack tables can look identical and have quite different house edges. These are the rules to check in the game information before you sit down.
| Rule | Better for you | Worse for you |
|---|---|---|
| Blackjack payout | 3 to 2 | 6 to 5, which adds well over a percentage point to the edge |
| Dealer on soft 17 | Stands | Hits |
| Double after split | Allowed | Not allowed |
| Surrender | Late surrender offered | No surrender |
| Number of decks | Fewer | More |
The payout rule outweighs everything else on the list. A 6 to 5 table turns a £10 blackjack into £12 instead of £15, and it happens roughly once every 21 hands. If you only check one thing, check that.
Should you take insurance?
No. Insurance is offered when the dealer shows an ace, and it pays 2 to 1 if the dealer has blackjack. Without counting cards you have no way of knowing whether the remaining deck is rich in tens, and on average the bet costs more than it returns. “Even money” on your own blackjack is the same bet in disguise, so the answer is the same.
What about side bets?
Side bets such as Perfect Pairs or 21+3 are separate wagers with their own paytables, and they generally carry a much higher house edge than the main game. They can be fun, but they undo much of the advantage basic strategy gives you. If you play them, treat them as a small extra and budget for them separately.
What are the most common mistakes?
- Standing on 12 to 16 against a high card because you are afraid of busting.
- Not doubling 11 against a dealer 10.
- Splitting 10s because the dealer looks weak. Twenty is already a winning hand.
- Never splitting 8s against a 9 or 10. Sixteen is the worst hand in the game; two hands starting with 8 are better.
- Raising stakes after losses. No staking pattern changes the edge. It only changes how fast you can lose.
Where does blackjack fit in UK rules?
The £5 and £2 stake limits introduced in 2025 apply to online slots, not table games, so blackjack tables at licensed UK casinos keep their own stake ranges. That makes your own limits more important, not less. Set a deposit limit before you play; our safer gambling tools guide shows how. Before you sit down at any table, run the two-minute register check in our guide to checking a casino licence.
Blackjack is still gambling, and the house still has the edge. If it stops being fun, the National Gambling Helpline is free on 0808 8020 133, and our responsible gambling page lists more support.