What each blackjack rule costs you
The short version: with perfect basic strategy, the house keeps about 0.36% of what you bet at a 6-deck table with good rules. By far the most costly rule is blackjack paying 6:5 (+1.39 points); next comes the dealer hitting soft 17 (+0.22).
The effect of each rule
Baseline: 6 decks, dealer stands on soft 17, double on any two cards and after splitting, late surrender, hole card, and blackjack pays 3:2. House edge with perfect strategy: 0.36%. Each row shows how much it changes if you change only that one rule.
| Rule | For you | Change in house edge |
|---|---|---|
| Blackjack pays 6:5 instead of 3:2 | Worse | +1.39 pts |
| Blackjack pays 1:1 (even money) | Worse | +2.27 pts |
| Dealer hits soft 17 (H17) | Worse | +0.22 pts |
| Double on 10 or 11 only | Worse | +0.18 pts |
| No doubling after a split | Worse | +0.14 pts |
| No hole card (dealer doesn’t peek) | Worse | +0.11 pts |
| Split only once | Worse | +0.10 pts |
| Double on 9, 10 or 11 only | Worse | +0.09 pts |
| No surrender | Worse | +0.07 pts |
| 8 decks instead of 6 | Worse | +0.02 pts |
| 4 decks instead of 6 | Better | −0.04 pts |
| Resplitting aces allowed | Better | −0.08 pts |
| 2 decks instead of 6 | Better | −0.17 pts |
| 1 deck instead of 6 | Better | −0.46 pts |
House edge at typical tables
| Table | House edge |
|---|---|
| Las Vegas, 6 decks, S17, surrender | 0.36% |
| Las Vegas, 6 decks, H17, surrender | 0.58% |
| European / online, no hole card | 0.54% |
| Casino in Spain | 0.63% |
| Double deck | 0.19% |
These figures assume you play basic strategy without mistakes. Every mistake costs you more: taking insurance, standing on 12 against a 2 or not splitting eights can easily add up to several points. That’s why the strategy chart matters more than hunting for the perfect table.
Where the numbers come from
The baseline edge and the effect of each rule are the standard approximations from the Wizard of Odds rule-effects table, the same one the Veintiuno app uses. The effects add up approximately: combining several rules can be off by a few hundredths from the exact calculation for that specific combination.
Frequently asked questions
Which blackjack rule is worst for the player?
Blackjack paying 6:5 instead of 3:2. It raises the house edge by about 1.4 percentage points, roughly quadrupling what you lose even with perfect play. If a table pays 6:5, your best move is to find another one.
What is the house edge in blackjack?
With perfect basic strategy, between 0.2% and 0.7% depending on the rules; with 6 decks and typical Las Vegas rules, about 0.4%. Playing by gut feel, the real edge is much bigger.
Does the number of decks matter?
Yes, but less than other rules. Going from 6 to 8 decks costs about 0.02 points; dropping to 2 decks saves you about 0.17. The blackjack payout and whether the dealer hits soft 17 matter far more.