Basic strategy in blackjack
Basic strategy is the set of mathematically best decisions in blackjack: whether to hit, stand, double, split or surrender for every combination of your hand and the dealer’s face-up card. It lowers the house edge to its minimum for that table’s rules, but it never removes it.
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Key takeaways
- Basic strategy tells you the best play for every hand against every dealer up-card.
- On common rules it brings the house edge down to roughly 0.5%, compared with about 5% for copying the dealer.
- The right chart depends on the table rules: decks, soft 17, doubling and the blackjack payout.
- It reduces the expected cost of playing; it does not turn blackjack into a winning game.
- Game
- Blackjack
- Purpose
- Lowest possible house edge
- Typical edge with it
- Around 0.5% on common rules
- Allowed in UK apps?
- Yes, charts are legal
- Beats the house?
- No
What basic strategy means
Blackjack is unusual among casino games because your choices change the result. Basic strategy is the answer to one question asked thousands of times: given my total and the dealer’s visible card, which action loses the least (or wins the most) on average? Mathematicians first worked it out in the 1950s, and computer simulations of millions of hands have since confirmed it for almost every rule variation.
The output is usually printed as a grid. Your hand runs down the side (hard totals, soft totals containing an ace counted as 11, and pairs), the dealer’s up-card runs across the top, and each cell holds a letter: H for hit, S for stand, D for double, P for split. Follow the grid every time and you are playing the version of the game with the lowest house edge the rules allow.
A basic strategy chart for common app tables
The table below summarises the key decisions for a multi-deck game where the dealer stands on soft 17 and you can double after splitting, which is a common set of rules on mobile blackjack. Different rules change some cells, so treat it as an illustration and check the rules in the game’s help screen.
| Your hand | Dealer shows 2–6 | Dealer shows 7–ace |
|---|---|---|
| Hard 17 or more | Stand | Stand |
| Hard 13–16 | Stand | Hit |
| Hard 12 | Hit against 2–3, stand against 4–6 | Hit |
| Hard 11 | Double | Double against 7–10, hit against ace |
| Hard 10 | Double | Double against 7–9, hit against 10 or ace |
| Soft 18 (ace-7) | Stand against 2, double against 3–6 | Stand against 7–8, hit against 9–ace |
| Pair of aces or 8s | Split | Split |
| Pair of 10s | Stand | Stand |
Two rules sit outside the grid. Never take insurance, because it is a separate bet that costs more than it saves for a player who isn’t tracking cards. And treat a pair of 5s as a hard 10 rather than splitting it.
How much basic strategy changes the house edge
On standard multi-deck rules with a 3:2 blackjack payout, perfect basic strategy leaves the casino an edge of roughly 0.5%. Copying the dealer (always hitting below 17, never doubling or splitting) is often estimated at around 5.5%, about ten times higher. Hunches land somewhere between, usually well above 1%.
Put that into pounds. Play 100 hands at £5 and you have staked £500. At 0.5% the expected cost is about £2.50; at 5.5% it is about £27.50. The result of any single session can still swing far either way, because variance dominates short runs, but the average cost of the hobby drops sharply.
Tables that pay 6:5 for a blackjack instead of 3:2 add roughly 1.4 percentage points to the house edge, which wipes out most of what careful play saves. The payout is printed on the felt or in the help screen.
Where you use basic strategy in a casino app
In RNG blackjack, the action buttons appear under your cards once the deal finishes: Hit, Stand, Double and, when allowed, Split. UK rules require at least five seconds per round on non-slot casino games, so there’s no rush to decide. In live dealer games a countdown bar runs at the bottom of the stream; if it expires, the table applies a default action that the help screen describes, which is often stand.
Keeping a chart as a screenshot in your Photos app is perfectly legal, and some players print one. On a phone, flick up to the app switcher, glance, and come back; on a tablet in landscape you have more room. The guide to playing blackjack on mobile covers the table layout, and multi-hand blackjack apps explains how the same decisions apply to several boxes at once.
Basic strategy and the RTP shown in the help screen
The Gambling Commission’s technical standards say that for games involving skill, the published return should be calculated using a standard published strategy. In practice, the RTP figure in a blackjack game’s help screen usually assumes optimal play. If you play differently, your real return is lower than the number on the screen.
Side bets such as Perfect Pairs or 21+3 have their own, usually higher, edge, and basic strategy does nothing to change it. The help screen lists each one separately.
What basic strategy can’t do
- It can’t make blackjack profitable over time; the house still keeps its edge.
- It isn’t card counting. Most RNG blackjack games use a freshly shuffled virtual shoe for every hand, so counting has nothing to work with.
- It doesn’t predict the next card; each deal comes from the RNG or a shuffled live shoe.
- It can’t justify raising stakes after losses. Progressive betting systems leave the edge untouched and raise the amount at risk.
Think of the chart as a way to pay the lowest price for the entertainment, alongside a budget you set before you start. The bankroll management guide and the safer gambling tools page cover deposit limits and time-outs you can switch on in any UK app.
Related blackjack terms
See house edge for the maths behind the percentages, side bet for the optional wagers, and the full casino app glossary for the rest. Our blackjack apps page compares where licensed UK apps place their tables.
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Frequently asked questions
Is it legal to use a basic strategy chart in a UK casino app?
Yes, using a basic strategy chart while you play is legal and doesn’t break any UK casino’s terms. It is simply a reference for decisions, not software that interferes with the game. You can keep it as a screenshot, a printed card or a note on a second device. Bots and automated tools are a different matter, because UK rules require you to commit to each round yourself. The blackjack apps guide explains how tables are laid out on a phone so you can find the buttons quickly.
Does basic strategy mean you will win at blackjack?
No, basic strategy lowers the casino’s advantage but doesn’t remove it, so you should still expect to lose over a long run of hands. On common rules the house edge falls to around 0.5%, meaning roughly 50p lost for every £100 staked on average. Short sessions can go either way because of variance. Treat the chart as a way to keep the cost of entertainment low, not as a route to profit, and read our house edge entry for the maths.
Should I ever take insurance in blackjack?
Under basic strategy you should never take insurance. Insurance is a side bet that the dealer has blackjack when showing an ace, paying 2:1, and the odds of that are worse than the payout implies for anyone not tracking which cards have been dealt. Even with a blackjack yourself, declining insurance (or ‘even money’) is the better long-run choice. In apps the insurance prompt appears as a pop-up with Yes and No buttons; tapping No is the chart’s answer every time.
Does basic strategy work in live dealer blackjack?
Yes, the same decisions apply in live blackjack because the maths depends on the cards and the rules, not on whether the dealer is a person. Check the table’s rules first, since live games vary in deck count and doubling options. The main practical difference is the decision timer: you get a set number of seconds to act before a default is applied. Our live blackjack apps page explains the timer, bet behind and mobile data use.
How long does it take to learn basic strategy?
Most players can learn the core of basic strategy in an evening or two, and the whole chart with a few weeks of practice. Start with the rules that cover most hands: stand on hard 17 or more, stand on 13–16 against a dealer 2–6, always split aces and 8s, never split 10s, and double 11 against most up-cards. Free-to-play blackjack in a UK app needs an age-verified account first, as explained in our demo mode entry.
Is basic strategy different for 6:5 blackjack tables?
The decisions barely change on a 6:5 table, but the game itself is far worse value. Paying 6:5 instead of 3:2 for a natural blackjack adds about 1.4 percentage points to the house edge, more than wiping out what perfect play saves. A £10 blackjack pays £12 instead of £15. Look for the payout on the felt or in the help screen before you sit down, and favour 3:2 tables. Our blackjack apps page explains where to find these rules.
Does basic strategy help with blackjack side bets?
No, basic strategy only covers decisions on your main hand and has no effect on side bets. Side bets such as Perfect Pairs, 21+3 or Bust It are settled on the cards dealt, with no decision from you, and they usually carry a much higher house edge than the main game. The game’s help screen lists the return for each side bet separately, so check it before adding one. Our side bet entry explains how they appear in mobile blackjack.