Double down in blackjack means doubling your original bet in exchange for exactly one more card, after which your hand stands. It is the move that lets you put more money out when the odds lean your way, most often on 10 or 11. Below are the exact rules, the totals basic strategy doubles on and what table restrictions cost.
Doubling down doubles your stake and gives you one card only.
Basic strategy doubles hard 11 against every dealer card except an ace (4–8 decks, dealer stands on soft 17).
Limiting doubles to 10 and 11 costs the player about 0.18%.
In no-hole-card games a dealer blackjack takes the doubled stake too.
Meaning
Double the bet, take one card
Usual timing
On your first two cards
Double on 10–11 only
Costs about 0.18%
No double after split
Costs about 0.14%
Chance of a 10-value card
16 in 52 (30.8%)
What double down means in blackjack
To double down is to add a second bet equal to your first, receive one more card and then stop. Wizard of Odds’ blackjack basics (opens in a new tab) define it in those words: the player doubles the bet and gets exactly one more card. You give up the right to keep hitting in return for twice the money on a hand that is likely to finish strong.
It is one of four choices on most blackjack hands, alongside hit, stand and split. A win pays even money on the full doubled stake, so a £10 bet doubled to £20 wins £20 rather than £10.
How to double down: the steps
Look at your first two cards and the dealer’s up card.
Check the table rules: some games allow doubling on any two cards, others only on 9–11 or 10–11.
Press Double online, or place a matching stack of chips beside your original bet at a land-based table.
Take the single card dealt to you; your hand now stands automatically.
Wait for the dealer to finish and settle the doubled stake.
You can double for less than your original stake at some land-based tables, but online games usually double the full amount. Check the game’s help screen.
Main doubling plays (4–8 decks, dealer stands on soft 17, double after split allowed)
Your hand
Double against
Otherwise
Hard 11
Dealer 2 to 10
Hit against an ace
Hard 9
Dealer 3 to 6
Hit
Soft 18 (A,7)
Dealer 3 to 6
Stand v 2, 7, 8; hit v 9, 10, ace
The reasoning is simple counting. A shoe holds 16 ten-value cards in every 52 (tens, jacks, queens and kings), so on 11 you have a 4 in 13 chance, about 30.8%, of making 21 with one card. When the dealer shows a weak card such as a 5 or 6, the dealer is also more likely to bust, which is why so many doubles are made against those cards.
Double down example: £10 on 11 against a dealer 6
You bet £10 and get 6 and 5 for hard 11. The dealer shows a 6. You double, putting in another £10, and draw a 9 for 20. The dealer turns a 10 for 16, draws a 7 and busts. You win £20 on the £20 stake. Had you just hit and won, the profit would have been £10. If the dealer had made 21, you would have lost £20 instead of £10, which is the price of doubling: bigger swings in both directions.
Double down rules that change the house edge
Tables limit doubling in different ways, and each limit costs you a little. Wizard of Odds’ rule variations table (opens in a new tab) measures them against an eight-deck game where the dealer stands on soft 17:
Doubling on 10 and 11 only: costs the player 0.18%.
Doubling on 9 to 11 only: costs 0.09%.
No doubling after a split: costs 0.14%.
European no-hole-card play: costs 0.11% in total, 0.08% of it from doubles, because a dealer blackjack takes the whole doubled stake.
Some branded games go the other way. Evolution’s Free Bet Blackjack gives a free double on hard 9, 10 and 11, and its Power Blackjack lets you double, triple or quadruple down on any two cards, though that game removes the 9s and 10s from the shoe. Read our blackjack house edge page for how rules add up.
Double down myths and mistakes
Doubling doesn’t create an edge for you. It only puts more money on hands where your expected result is better than average, which trims the overall house edge when done correctly. Doubling on hunches, such as hard 12 because you feel lucky, does the opposite. Doubling against a dealer ten or ace in a no-hole-card game is rarely right, and the common blackjack mistakes page lists others to avoid. Outside casinos, double down means to commit harder to something; at the table it is a precise rule.
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Frequently asked questions
What does double down mean in blackjack?
Double down means doubling your original bet and taking exactly one more card, after which your hand stands. It is used when your first two cards make a strong starting total, usually 10 or 11, so one card is likely to give you a good hand. A win pays even money on the doubled stake. Our how to play blackjack guide explains where doubling fits among the other choices.
Should you always double down on 11?
Not always: in a 4–8 deck game where the dealer stands on soft 17, basic strategy doubles hard 11 against everything except a dealer ace. Against an ace you hit instead. In no-hole-card games, doubling against a ten or ace is rarely correct, because a dealer blackjack takes your doubled stake. We look at this exact question in is doubling down on 11 always right.
Can you double down after splitting?
It depends on the table; many games allow it, but some don’t. The rule is often shown as DAS (double after split). Wizard of Odds puts the cost of a no-DAS rule at about 0.14% for the player. Lightning Blackjack, for example, allows one split only and no double after split, according to Wizard of Odds. See can you double after splitting for the full answer.
Can you double down for less than your bet?
Sometimes, at land-based tables, but online games usually double the full stake. Doubling for less is almost never a good idea anyway: if basic strategy says double, it is because the extra money is placed on a favourable hand, so putting in less wastes part of that value. Check the game’s help screen for the exact rule. Our blackjack basic strategy page sets out the doubling plays.
What happens if the dealer has blackjack after I double?
In a peek game you won’t get the chance, because the dealer checks for blackjack first and settles the hand before you can double. In a European no-hole-card game the dealer takes a second card only after you play, and under the rules Wizard of Odds analyses you lose the full doubled amount. That is why doubling against a ten or ace is rare there. See our page on no hole card rules.
Is doubling down a way to win at blackjack?
No. Correct doubling reduces the house edge, but it does not remove it. You are placing more money on hands where your chances are better than average, which improves your expected result compared with never doubling. Over time the casino still keeps its edge, and short sessions vary widely. Our answer to can you win at blackjack in the long run explains why.
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