Blackjack's basic ruleset is nearly identical from one table to the next, yet the house edge under perfect basic strategy ranges from a 0.18% player edge on one specific rule combination to a 1.79% house edge on another, both still called "blackjack." The difference sits entirely in deck count, three dealer and payout rules, and how they combine.
Basic Ruleset
Objective
Each player competes against the dealer's hand only, not against other players at the table. A hand beats the dealer by totaling closer to 21 without exceeding it, or by the dealer busting first. A hand exceeding 21 loses immediately regardless of the dealer's total.
Card Values
Cards 2 through 10 count at face value. Jack, Queen and King each count as 10. An Ace counts as 1 or 11, whichever produces the better total without exceeding 21.
Player Actions
Hit adds one card to the current hand. Stand ends the turn with the current total. Double down doubles the original bet in exchange for exactly one more card, after which the hand stands automatically. Split divides two cards of equal rank into two separate hands, each requiring an additional matching bet. Surrender, where offered, forfeits half the original bet and ends the hand immediately.
Dealer Rules
The dealer draws cards according to a fixed procedure with no discretion: hit any total of 16 or below, and either stand or hit on a soft 17, a hand containing an Ace counted as 11 that totals 17. Which of those two the dealer follows, stand on soft 17 or hit on soft 17, is a rule set by the specific table, not a choice the dealer makes hand to hand.
Payout Table
Last verified: 11 September 2026, standard bet outcomes
| Outcome | Payout |
|---|---|
| Blackjack (Ace plus 10-value card), 3:2 payout tables | 3 to 2 |
| Blackjack, 6:5 payout tables | 6 to 5 |
| Standard win | 1 to 1 |
| Push (tie with dealer) | Stake returned |
| Insurance, offered when dealer shows an Ace | 2 to 1 |
| Surrender, where offered | Half stake returned, hand ends |
Where the House Edge Actually Comes From
The dealer's structural advantage is procedural, not a worse set of odds on any individual card. Players act first and can bust before the dealer draws a single additional card, which means a player total over 21 loses immediately even in hands where the dealer would also have busted. That sequencing, not the card values themselves, is the entire mechanical source of the house's edge in blackjack, before any rule variant is applied on top of it.
Every figure in this article assumes flawless basic strategy, the mathematically optimal decision for every hand and dealer up-card combination, verified through combinatorial analysis rather than simulation. Deviating from basic strategy raises the house edge above every figure listed here, regardless of which rule variant is in play.
Deck Count and the House Edge
All figures below: dealer stands on soft 17, double after split allowed, blackjack pays 3:2, basic strategy
| Decks | House edge |
|---|---|
| 1 | 0.18% (player edge) |
| 2 | 0.18% |
| 4 | 0.35% |
| 6 | 0.40% |
| 8 | 0.43% |
More decks in play very slightly increase the house edge under identical dealer and payout rules, because a larger shoe changes the probability distribution of specific card combinations, splits and blackjacks fractionally in the dealer's favor. The single-deck figure above, a 0.18% player edge, describes a specific and increasingly rare rule combination, discussed further below.
Dealer Soft 17 Rule
6 decks, double after split allowed, blackjack pays 3:2, basic strategy
| Dealer rule | House edge |
|---|---|
| Stands on soft 17 (S17) | 0.40% |
| Hits on soft 17 (H17) | 0.62% |
Requiring the dealer to hit a soft 17 rather than stand raises the house edge by 0.22 percentage points under otherwise identical rules. The dealer drawing an additional card on a soft 17 gives the dealer a further chance to improve that hand, a chance a stand-on-soft-17 dealer never gets.
Double After Split
6 decks, dealer stands on soft 17, blackjack pays 3:2, basic strategy
| Rule | House edge |
|---|---|
| Double after split allowed (DAS) | 0.40% |
| Double after split not allowed | 0.54% |
Removing the option to double a hand's bet after splitting a pair raises the house edge by 0.14 percentage points, since it removes a specific value-adding play, doubling on a strong post-split total, that basic strategy otherwise calls for in certain hands.
Blackjack Payout: 3:2 vs 6:5
6 decks, dealer stands on soft 17, double after split allowed, basic strategy
| Blackjack payout | House edge |
|---|---|
| 3 to 2 | 0.40% |
| 6 to 5 | Approximately 1.79% |
The 6:5 figure above is derived rather than published as a single directly verified combination: it combines the 0.40% baseline with a separately published 1.39 percentage point penalty specifically attributable to the reduced blackjack payout, both figures sourced from Wizard of Odds. A 6:5 payout on a natural blackjack is a meaningfully larger structural change to the house edge than any single dealer or splitting rule covered above, since blackjacks occur often enough across a full session for the reduced payout to compound significantly.
Late Surrender
6 decks, dealer stands on soft 17, double after split allowed, basic strategy
| Rule | House edge |
|---|---|
| No surrender | 0.40% |
| Late surrender available | Approximately 0.33% |
This figure is also derived, combining the 0.40% baseline with a separately published surrender value of 0.07 percentage points. Late surrender allows forfeiting half the original stake on specific weak starting hands against strong dealer up-cards, reducing the average loss on those particular hands without eliminating it.
Insurance
Insurance is offered whenever the dealer's up-card is an Ace, before the dealer checks for blackjack. A player may bet up to half the original stake that the dealer's hidden card is a 10-value card, paying 2 to 1 if correct.
Treating the shoe as an even distribution of ranks, 4 of the 13 ranks (10, Jack, Queen, King) are 10-value cards, so a player wins the bet on roughly 4 in 13 dealer up-cards and loses on the remaining 9 in 13. Expected value per unit staked works out to (4/13 × 2) plus (9/13 × −1), which equals −1/13, or approximately 7.69%. That figure shifts slightly with the exact composition of cards already dealt from a specific shoe, but it sits well above the house edge on the main hand under every rule combination in this article, regardless of deck count or dealer rule.
Full Variant Comparison
Basic strategy, house edge by rule combination, last verified 11 September 2026
| Rule combination | House edge |
|---|---|
| 1 deck, S17, DAS, 3:2 | 0.18% (player edge) |
| 2 decks, S17, DAS, 3:2 | 0.18% |
| 4 decks, S17, DAS, 3:2 | 0.35% |
| 6 decks, S17, DAS, 3:2 | 0.40% |
| 6 decks, H17, DAS, 3:2 | 0.62% |
| 6 decks, S17, no DAS, 3:2 | 0.54% |
| 6 decks, S17, DAS, late surrender, 3:2 | Approximately 0.33% |
| 6 decks, S17, DAS, 6:5 | Approximately 1.79% |
| 8 decks, S17, DAS, 3:2 | 0.43% |
Why This Range Exists on One Game
Every figure on this page describes the identical game, blackjack, under different specific rule combinations a table can legally offer. The gap between the best and worst figures listed, 0.18% up to roughly 1.79%, is wider than the gap between several entirely different casino games covered elsewhere on this site. The rule set posted at a specific table, not the name of the game, is what determines which end of that range applies.
The single-deck, stand-on-soft-17, double-after-split figure at the top of this page describes a rule combination rarely offered in its complete, unmodified form at a live table, and even where a table's posted rules match it, that figure describes performance under flawless basic strategy applied to every hand, computed through exhaustive combinatorial analysis rather than observed at any specific table. Nothing in this article recommends seeking out a specific rule combination or suggests any sequence of bets changes the mathematics described here.
Responsible Gambling
Any operator offering blackjack to players in Malta must hold a Malta Gaming Authority licence, and self-exclusion and deposit-limit tools are required to be available on every licensed platform. Every figure in this article, including the lowest, still describes a game played against a structural house advantage over any extended series of hands, and the Responsible Gaming Foundation provides free, confidential support for anyone who wants it.