Blackjack is known for having a relatively low house edge, but there is no single percentage that applies to every blackjack table.
The blackjack house edge changes according to the rules of the game, including the blackjack payout, number of decks, dealer rules, and the options available for doubling and splitting.
Understanding these differences makes it easier to compare blackjack variants and understand what their advertised RTP percentages actually mean.
What Is the House Edge in Blackjack?
The house edge is the casino’s average mathematical advantage over the player over the long term. It is expressed as a percentage of total wagers.
Suppose a blackjack game has a 0.5% house edge. Theoretically, the casino expects to retain an average of $0.50 for every $100 wagered over a very large number of hands.
That doesn’t mean you’ll lose exactly $0.50 after betting $100. You could win, lose considerably more, or finish close to even.
House edge describes long-term mathematical expectation, not the outcome of an individual hand or session.
How Does the Blackjack House Edge Work?
Blackjack gives the casino an underlying advantage because the player acts before the dealer. If you go over 21, you immediately lose your wager, even if the dealer later busts too.
The exact size of that advantage then depends on the rules.
With favorable rules and appropriate basic strategy, blackjack can have a house edge below 1%. However, changing the payout for blackjack, dealer behavior, deck count, or player options can increase or decrease that percentage.
That is why an advertised blackjack house edge applies only to a specific set of rules and assumptions.
House Edge vs. RTP
House edge and return to player (RTP) describe opposite sides of the same calculation.
| House edge | Theoretical RTP |
| 0.40% | 99.60% |
| 0.50% | 99.50% |
| 1.00% | 99.00% |
| 1.50% | 98.50% |
| 2.00% | 98.00% |
The calculation is:
RTP = 100% − house edge
A blackjack game with a 0.5% house edge therefore has a theoretical RTP of approximately 99.5%.
Neither figure predicts your short-term results. A 99.5% RTP does not mean you’ll receive exactly $99.50 back after wagering $100.
What Changes the House Edge in Blackjack?
Blackjack exists in many forms, and small rule changes can alter the probabilities. The most important details include:
- Blackjack payout: 3:2 is more favorable to the player than 6:5.
- Dealer soft 17: the dealer standing on soft 17 generally produces a lower house edge than hitting.
- Number of decks: fewer decks can slightly favor the player when all other rules remain equal.
- Doubling: more opportunities to double generally benefit the player.
- Double after split: allowing this option slightly reduces the house advantage.
- Surrender: having surrender available can lower the house edge when used appropriately.
- Splitting restrictions: tighter restrictions generally increase the casino’s advantage.
This means two blackjack games can look almost identical while having different house edges.
Why the Blackjack Payout Matters
One of the first rules to check is the payout for a natural blackjack.
Traditional blackjack pays 3:2. Some tables instead pay 6:5.
Here’s what that difference looks like:
| Bet | 3:2 blackjack win | 6:5 blackjack win |
| $5 | $7.50 | $6 |
| $10 | $15 | $12 |
| $25 | $37.50 | $30 |
| $100 | $150 | $120 |
The difference is significant over time because natural blackjacks occur often enough for the lower payout to affect the game’s overall mathematics.
Changing a standard 3:2 payout to 6:5 can add approximately 1.39 percentage points to the house advantage, assuming the other rules stay the same.
This makes the blackjack payout one of the most important rules to check when comparing tables.
Dealer Hits or Stands on Soft 17
A soft 17 is a hand totaling 17 that includes an Ace counted as 11, such as Ace-6.
Blackjack tables generally use one of two rules:
S17: Dealer stands on soft 17.
H17: Dealer hits soft 17.
S17 is generally more favorable to the player. Requiring the dealer to hit soft 17 can increase the house advantage by around 0.22 percentage points under commonly analyzed blackjack rules.
The difference is relatively small compared with switching from a 3:2 to 6:5 payout, but it still matters when comparing similar games.
Does the Number of Decks Affect House Edge?
Yes, although deck count should never be considered on its own.
When all other rules remain equal, fewer decks generally produce a slightly lower house edge.
However, casinos can combine fewer decks with less favorable rules. For example, a single-deck table might pay 6:5 for blackjack rather than 3:2. The reduced payout can more than cancel out the mathematical benefit of having fewer decks.
In other words, single-deck blackjack doesn’t automatically mean better odds. Always consider the complete ruleset.
How Doubling and Splitting Affect House Edge
Player options also influence blackjack’s mathematical advantage.
Rules that provide more flexibility generally favor the player. For example, allowing players to double after splitting can slightly reduce the house edge because it provides another opportunity to increase a wager in favorable situations.
Other differences include which totals can be doubled, how many times pairs can be split, and whether Aces can be resplit.
You don’t need to calculate the effect of every rule yourself. Checking these details simply helps explain why two blackjack games may publish different RTP figures.
For more information about how to play individual hands, see our blackjack strategy guide.
House Edge in Different Blackjack Variants
Different blackjack variants have different house edges because they modify the traditional rules.
Importantly, names such as “European Blackjack” or “Classic Blackjack” don’t guarantee a specific percentage. Rules can vary between casinos and software providers.
Classic Blackjack
Classic Blackjack generally stays close to traditional rules, with actions such as hit, stand, double, and split.
Natural blackjack commonly pays 3:2, but you should still check the game’s rules because deck count and dealer behavior can vary.
European Blackjack
In many European Blackjack games, the dealer initially receives only one card and doesn’t draw a second until players have completed their hands.
Depending on the exact rules, players may lose additional wagers from doubles and splits if the dealer subsequently draws blackjack. This European no-hole-card rule can increase the house advantage compared with otherwise similar games.
Atlantic City Blackjack
Atlantic City Blackjack is commonly associated with rules such as eight decks, dealer standing on soft 17, late surrender, doubling after splitting, and 3:2 blackjack payouts.
Individual versions can still differ, so the name alone shouldn’t be used to determine the house edge.
Vegas Strip Blackjack
Vegas Strip Blackjack commonly uses four decks and offers 3:2 blackjack payouts, doubling after splitting, and a dealer who stands on soft 17.
Again, check the specific rules because online versions aren’t necessarily identical.
Blackjack Switch
Blackjack Switch gives players two hands and allows them to swap the second card dealt to each hand.
That player-friendly option is balanced by other rule changes. For example, in common versions of the game, a dealer total of 22 pushes against surviving player hands rather than losing.
This illustrates how blackjack variants work: an additional player advantage may be offset by another rule favoring the house.
Do Blackjack Side Bets Have the Same House Edge?
No. Side bets have their own payouts, probabilities, and house edges.
These wagers can cover outcomes such as pairs, suited cards, specific three-card combinations, or the dealer busting.
A blackjack table could therefore offer a relatively low house edge on the main game while its optional side bets carry a considerably higher advantage for the casino.
If an online blackjack game advertises an RTP for the main game, don’t assume that percentage also applies to its side bets.
Does Basic Strategy Remove the House Edge?
No. Basic strategy identifies mathematically appropriate decisions based on your cards, the dealer’s upcard, and the rules being played. Using it can keep the house edge relatively low, but it doesn’t guarantee a profit or remove the casino’s long-term mathematical advantage.
This also provides important context for published blackjack percentages. When a game is described as having a house edge of 0.5%, that calculation will typically assume appropriate decisions.
