When to double down in blackjack

What doubling down means at the table

Doubling down is an option on your first two cards: you place a second stake equal to the first and receive exactly one more card, then your hand is finished. The Wizard of Odds blackjack basics (opens in a new tab) define it in just those terms. You are trading the freedom to keep drawing for twice the money on a hand that is, on average, in good shape.

The reason to double is simple. In a few spots your two cards plus the dealer's face-up card make your hand a favourite, so putting more money on it raises your average return from that hand. Everywhere else, the extra stake magnifies a hand that is not a favourite, or the one-card limit stops you improving a hand that needs several cards. Our blackjack hub covers the other options, and the double down glossary entry gives a short definition.

When to double down in blackjack: the full list

The doubles below come from the Wizard of Odds 4 to 8 deck basic strategy (opens in a new tab), which assumes the dealer stands on soft 17 and you may double after splitting. If a hand is not on this list, do not double it.

Three patterns are worth remembering. Hard 11 is the strongest doubling hand. Every soft double is against a dealer 3 to 6. And no hand of 8 or less, or 12 or more, is ever doubled under this rule set. For the rest of the decisions, see basic strategy or the interactive strategy chart.

The odds of your one card

Because a double gives you one card only, it is worth knowing what that card is likely to do. Treating the shoe as endless, every rank turns up 1 time in 13, and an ace drawn to a hard 11 counts as 1.

None of these hands can bust on one card, which removes the main danger of a double. What separates them is how often they finish on a strong total and how weak the dealer's card is. Hard 11 and hard 10 reach 17 or better equally often, but 11 makes 21 with any ten-value card (4 in 13, about 30.8%), so it is doubled against more dealer cards. Hard 9 reaches a strong total less often, so it is doubled only against the weakest dealer cards.

Hard 11 against an ace is hit, not doubled, in the stand-on-soft-17 chart. Other rule sets change some borderline doubles, so check the chart for your exact game. Our answer on whether doubling 11 is always right looks at this case.

Doubling soft hands

Soft doubles surprise many players. Ace-two against a 5 does not look like a strong hand, but a soft hand cannot bust on one card and a dealer 5 or 6 is the weakest start the dealer can have. The chart takes advantage of both facts at once.

Soft 18 is the special case. Against a 3 to 6 it is a double; if your table does not let you double, or you already hold three cards, you stand instead of hitting. All the other soft doubles fall back to a hit. Our guide to soft 18 explains the three different plays for ace-seven.

Worked double-down examples in pounds

Hard 11 against a 6. You bet £25 with 8-3. You double to £50 and draw a queen: 21. The dealer turns over a 10, giving 16, draws and busts. You win £50 profit instead of £25. Had you drawn a 2 instead, you would be stuck on 13 with £50 at risk and no further card, relying on the dealer to bust. That is the trade every double makes.

Soft 17 against a 4. You bet £10 with ace-six and double to £20. A 3 gives soft 20; a 9 gives hard 16. Either way you stop there. Across many hands the double earns more than simply hitting, but the swings are bigger, so plan your budget around the doubled stakes.

Budget effect. If you sit down with £100 and bet £10 a hand, a run of doubles can put £20 on several hands in a row. That is normal variance, not a sign to change your stake. Our blackjack bankroll guide and variance explainer show how to size a session around these swings.

Doubling rules and what they cost

Not every table lets you double on any two cards. The Wizard of Odds rule variations (opens in a new tab) table shows how much each restriction costs against an eight-deck, stand-on-soft-17 baseline.

Doubling is worth a lot to the player: removing it entirely costs more than the whole house edge of a good game. A ban on doubling soft hands, which is what a 9 to 11 or 10 to 11 restriction amounts to, costs much less. When comparing tables, the blackjack house edge page puts these rules together with deck counts and payouts.

Doubling in no-hole-card and European games

In the standard peek game, the dealer checks for blackjack when showing a ten or an ace, so you never double into a dealer blackjack. In a no-hole-card game the dealer takes a second card only after players finish. Under the European no-peek rule as analysed by Wizard of Odds, if the dealer then makes blackjack, you lose everything you bet, including the doubled stake.

Example: you bet £10 on 6-5 against a dealer 10 and double to £20. The dealer draws an ace for blackjack. In a peek game the hand would have ended before you could double, costing £10. Under the European no-peek rule, you lose £20. This is why doubling against a dealer ten or ace is rarely correct in no-hole-card games, and why Wizard of Odds publishes a separate European blackjack strategy (opens in a new tab). Settlement rules for doubled bets differ between games, so read the help screen before you play. Our European blackjack page covers the full rule set.

Doubling in branded and variant games

• Free Bet Blackjack: Evolution's Free Bet Blackjack game page (opens in a new tab) lists a free double on two-card hard 9, 10 and 11, offered automatically. Wizard of Odds puts the game's house edge at 1.04%, and a dealer 22 pushes against your hand. See Free Bet Blackjack.
• Power Blackjack: Evolution's Power Blackjack rules (opens in a new tab) allow doubling, tripling or quadrupling on any two initial cards, even after a split, with the 9s and 10s removed from the shoe. See Power Blackjack.
• Spanish 21: redoubling is allowed at some tables; Wizard of Odds puts the edge at 0.42% with redoubling and 0.76% without, both with the dealer hitting soft 17. See Spanish 21.
• Lightning Blackjack: Wizard of Odds reports one split only and no double after splitting. See Lightning Blackjack.

Each variant's doubling rules change the right strategy, so a standard chart is only a starting point for these games.

How to double down online

1. Check the help screen for doubling rules: any two cards or 9 to 11 only, and whether you can double after a split.
2. Make sure your balance covers a second stake equal to your first; the Double button will not appear otherwise.
3. Compare your first two cards and the dealer's face-up card with the doubling list.
4. Press Double. The extra stake is placed and you receive one card.
5. Wait for the dealer to finish; your hand is settled at the doubled amount.

Doubling mistakes and myths

• Doubling 11 against an ace in a stand-on-soft-17 game. The chart hits.
• Doubling 10 against a 10. The chart hits; the dealer's card is as strong as yours.
• Doubling only when you feel lucky. The decision depends on the cards, not on how the last few hands went. Earlier results have no bearing on the next one; see independent events.
• Never doubling soft hands. Players miss value with ace-four against a 5 or ace-seven against a 6.
• Doubling to win back losses. A double raises your stake on one hand; it does not change the edge. If you are chasing, stop and read our page on chasing losses.

Doubling correctly helps reduce the house edge, but the game still favours the casino over time. Our common blackjack mistakes page lists other errors that cost money.

UK rules and doubling at live and RNG tables

Doubling works the same way at live blackjack and RNG tables, but live games give you a short timer to decide, so know your doubles before the cards come out. Since 17 January 2025, Gambling Commission rules require each round of an online casino game other than a slot to take at least 5 seconds, ban autoplay for casino games including live ones, and require your net spend and time played to be visible. The slot stake caps do not apply to blackjack, so it is up to you to keep doubled stakes within your budget. For free, confidential support, the National Gambling Helpline is on 0808 8020 133, run by GamCare.

Partner casinos and blackjack doubles

The welcome offers we list are aimed at slots, not at doubling decisions at a blackjack table. If you want to play blackjack at one of these casinos, look at its table-game lobby and check whether card games count towards any bonus; often they do not, or count only partly. Everything here is 18+ and terms apply.

• Casumo offers new customers who opt in a 50% bonus up to £100 on a first deposit of at least £20, with 10x bonus wagering within 7 days and a £5 maximum bet while the bonus is active. Game, play and payment restrictions apply.
• 10bet gives new UK customers a 100% match up to £25 if they choose the casino bonus and deposit within 7 days of joining; wager the bonus 10x on slots within 3 days. Maximum bonus winnings are £1,000, and Skrill and Neteller deposits don't qualify.
• Coral gives new players 100 free spins worth 10p each on selected slots after a deposit and £10 of slot bets, from 1 October 2026 to 1 February 2027. Accept the spins within 48 hours and use them within 7 days; winnings have no wagering. Certain payment methods are excluded.

Our blackjack bonus guide explains how bonus terms usually treat card games, and game weighting covers why blackjack often counts for less.

18+. Every casino game has a built-in house edge, so over time you should expect to lose what you stake. Set a budget before you play and stop when it’s gone: safer gambling tools and support. Free, confidential help: National Gambling Helpline 0808 8020 133.