Blackjack House Edge by Rules
With perfect basic strategy, a blackjack game with good rules keeps about 0.57% of every bet for the house over the long run. Each table rule moves that number. Starting from a game where the dealer stands on soft 17, you can double on any two cards and after splitting, and blackjack pays 3:2, the table shows what each common rule adds or takes away.
The short answer
A 6:5 blackjack payout is by far the costliest rule: it adds about 1.35 percentage points, more than all the other bad rules below put together (0.71 points). If a table pays 6:5, the other rules hardly matter. Late surrender is the one common rule here that helps you.
What each rule does to the house edge
| Rule | Change (percentage points) | House edge |
|---|---|---|
| Base: stands on soft 17, double any two cards and after split, 3:2 | base | 0.57% |
| Blackjack pays 6:5 | +1.35 | 1.92% |
| Dealer hits soft 17 | +0.22 | 0.79% |
| Double on 10 or 11 only | +0.17 | 0.74% |
| No double after split | +0.12 | 0.69% |
| No hole card (European) | +0.11 | 0.68% |
| Double on 9 to 11 only | +0.09 | 0.66% |
| Late surrender offered | −0.09 | 0.48% |
A positive change means the house keeps more. Each row changes one rule from the base game.
Some complete rule sets
| Game | Rules | House edge |
|---|---|---|
| Online Casino preset | Dealer hits soft 17, double any two cards and after split, 3:2 | 0.79% |
| European preset | Stands on soft 17, double 9 to 11 only, no double after split, no hole card, 3:2 | 0.88% |
| A 6:5 table | Dealer hits soft 17, double any two cards and after split, 6:5 | 2.14% |
Rule effects roughly add up
To estimate any table, start from 0.57% and add the change for each of its rules. For this site's European preset (no double after split, doubling only on 9 to 11, no hole card), adding the three changes gives 0.89%; working out the whole game gives 0.88%.
Why 6:5 costs so much
You are dealt a blackjack in about one hand in 21 (4.7%). At 3:2 it pays $1.50 per $1 bet; at 6:5 it pays $1.20. That 30 cent difference on one hand in 21 comes to about 1.35 percentage points once the hands where the dealer also has blackjack, and you push, are taken into account.
What about the number of decks?
These figures use an infinite deck, which is the least favourable shoe for the player. With the same rules, real 6 and 8 deck games have a slightly lower house edge than shown here, and single and double deck games lower still.
How these numbers are calculated
Every starting hand against every dealer upcard is played its best way, using the same engine as the calculator on this site with an infinite deck. The dealer checks for blackjack first, except in the no hole card game, and surrender is late surrender. Split hands are not resplit, which overstates the house edge by a few hundredths of a point where resplitting is allowed.
As a cross-check, this site's tests run the simulator for 1,000,000 rounds of the base game, the dealer hits soft 17 game and the 6:5 game, and require each result to land within three standard errors of these figures.