Game Theory Analysis
BLACKJACK
Blackjack
House Edge: ≈0.5 to 0.7%
Blackjack is the most popular casino game in the world.
Unlike most casino games, which are largely passive, Blackjack requires players to make decisions every hand, meaning the effective house edge depends heavily on player skill and making it very exciting.
For most casinos, it’s the lowest edge game you can play, compared against a 2.7% HE on a roulette, for BJ it can go as low as 0.3% HE. However, mistakes are costly.
Duel offers strong BJ options at the top end of the market, with house edge typically around ≈0.5 to 0.7%.
OBJECTIVE
Get closer to 21 than the dealer without going over.
Aces count as 1 or 11.
ROUND START
- You get 2 cards face up.
- Dealer shows 1 upcard.
- You choose actions based on your hand and that upcard.
MOVES
| Move | What it Does | Strategy Tip |
|---|---|---|
| Hit | Take one more card and keep going unless you bust or stand. | Usually hit 12-16 vs dealer 7+. |
| Stand | Keep your current total and end your turn. | Often stand 12-16 vs dealer 2-6. |
| Double | Double your bet, take exactly one card, then stop. | Best on strong starts like 10 or 11. |
| Split | Turn a pair into two separate hands. | Use when pair rules favor two hands over one. |
HAND TYPES
| Hand Type | Meaning | Example |
|---|---|---|
| Hard Hand | One practical total. | 9 + 3 = 12 |
| Soft Hand | Contains an Ace counted two ways. | A + 5 = 6 or 16 |
| Pair | Two cards of same rank; can be split if allowed. | 8 + 8 |
RESULTS
- Blackjack: 21 on your first two cards pays 3:2.
- Dealer Rule: Dealer must stand on all 17 totals.
- Push: If your final total matches the dealer, it is a push.
- Bust Loss: If you go over 21, you lose immediately, no matter what the dealer has.
- Win Condition: You win if your final total is higher than the dealer without busting, or if the dealer busts.
All of the live Blackjack Rooms are available across all casinos, as they're provided by third-party developers with one exception: Duel Live Blackjack, which is a Duel Original.
Duel offers 50% rakeback on many third-party live tables, making it one of the strongest-value places to play these rooms while still generating leaderboard points. Other providers offer smaller bonuses that rarely offset even 20% of the house edge.
Internal BJ rooms are not live, and are provavly fair.
Duel/Stake/Shuffle/Gamdom Internal Blackjack
All of these provider have the same Blackjack rule in their internal BJ. The only difference is the rakeback given in each. 50k at 100% rakeback in Duel, 5k in Gamdom, and the rest give much smaller percentages, can be nothing if not tiered.
- Decks: Infinite
- Dealer: Peeks always, stands on soft 17
- Split: 1 max, no hit on split Aces
- Double On: Any Card
- Double After Split: Allowed
- Surrender: Not allowed
Rainbet Internal Blackjack
Rainbet Internal BJ keeps the same favorable peek / S17 / DAS structure as Duel Internal, but runs an 8-deck shoe instead of the infinite model. That lowers the exact house edge to about 0.4910% on optimal play and 0.5019% on chart/basic strategy.
- Decks: 8
- Dealer: Peeks always, stands on soft 17
- Split: 1 max, no hit on split Aces
- Double On: Any Card
- Double After Split: Allowed
- Surrender: Not allowed
Duel Live Blackjack
Another Duel Live original, like Castle Roulette, not only does this BJ have the best odds around, but it's probably the most entertaining one, with the best mix of hosts from dwarfs to knights, jesters, and unexpected characters.
- Decks: 8
- Dealer: Peeks only on Ace, stands on soft 17
- Split: 1 max, no hit on split Aces
- Double On: Any Card
- Double After Split: Allowed
- Surrender: Not allowed
Evolution Blackjack
Live BJ with basic rules and 8 decks. No doubling after split keeps the edge higher than the most player-friendly variants.
- Decks: 8
- Dealer: Peeks only on Ace, stands on soft 17
- Split: 1 max, no hit on split Aces
- Double On: Any Card
- Double After Split: Not Allowed
- Surrender: Not allowed
Pragmatic Blackjack
Same rules as Evolution, but since you are able to double after split, it gives better odds to the player.
- Decks: 8
- Dealer: Peeks only on Ace, stands on soft 17
- Split: 1 max, no hit on split Aces
- Double On: Any Card
- Double After Split: Allowed
- Surrender: Not allowed
Evolution Infinite Blackjack
It is the same rules as Evolution Blackjack, but it is played with 6 Card Charlie, meaning that if you get 6 cards on your hand, you win even against a dealer BJ.
- Decks: 8 (continuous)
- Dealer: Peeks only on Ace, stands on soft 17
- Split: 1 max, no hit on split Aces
- Double On: Any Card
- Double After Split: Not Allowed
- Surrender: Not allowed
- Extras: 6 Card Charlie: 6 cards = automatic win (even vs dealer blackjack)
01Blackjack Payout
+
Blackjack Payout
Meaning
Determines how much a natural blackjack (Ace + 10-value card) pays.
Possible Values
Player Impact
Why
3:2 returns 1.5x the bet, while 6:5 returns only 1.2x.
This is one of the biggest RTP drivers in blackjack. Never even entertain playing any room that pays 6:5.
Effect on RTP
- 3:2 vs 6:5 -> +~1.3 to +1.4 percentage points
02Number of Decks
+
Number of Decks
Meaning
The number of standard 52-card decks used in the shoe.
Possible Values
Player Impact
Why
More decks reduce blackjack frequency and weaken card-removal effects, slightly lowering RTP.
With one deck, the dealt cards give a lot more information. Once you get to 6 decks or more, the difference is smaller.
Effect on RTP
- 6 decks vs 8 decks -> +0.022 pp
- 8 decks vs infinite -> +0.065 pp
- 6 decks vs infinite -> +0.087 pp
03Dealer Peeking
+
Dealer Peeking
Meaning
Determines whether the dealer checks for blackjack before players act.
Possible Values
Player Impact
Why
Early checking prevents players from losing extra bets on doubles and splits against dealer blackjack.
If the dealer has blackjack, the hand ends immediately. If not, you gain information that can improve later decisions.
Effect on RTP
- always vs only ace -> +0.097 pp
- only ace vs never -> +0.007 pp
- always vs never -> +0.104 pp
05Dealer Stands on Soft 17
+
Dealer Stands on Soft 17
Meaning
Determines whether the dealer stands or hits on soft 17 (Ace + 6).
Possible Values
Player Impact
Why
Hitting soft 17 lets the dealer improve weak hands more often.
06Double Down Restrictions
+
Double Down Restrictions
Meaning
Determines which starting hands are allowed to double.
Possible Values
Player Impact
Why
More flexibility lets players maximize value in profitable spots, especially on soft hands.
Effect on RTP
- Any 2 cards vs 9/10/11 only -> +0.093 pp
07Double After Split
+
Double After Split
Meaning
Determines whether players can double after splitting pairs.
Possible Values
Player Impact
Why
This is one of the clearest player-friendly rules: split hands still create profitable double spots, and DAS lets you capture them.
Effect on RTP
- DAS vs no DAS -> +0.112 pp
08Maximum Splits
+
Maximum Splits
Meaning
Determines how many times a player can split pairs.
Possible Values
Player Impact
Why
Splitting lets players exploit favorable pair situations more often.
Effect on RTP
- 2 splits vs 1 split -> +0.107 pp
10Surrender
+
Surrender
Meaning
Determines whether players can surrender and when.
Possible Values
Player Impact
Why
Surrender lets players minimize losses in highly unfavorable spots.
You get 50% of your bet back if you decide not to play the hand.
Effect on RTP
- Late surrender vs none -> +0.082 pp
11Charlie Rule
+
Charlie Rule
Meaning
Determines whether reaching a certain number of cards without busting is an automatic win, even against dealer blackjack.
Possible Values
Player Impact
Why
Automatic wins meaningfully increase RTP.
Effect on RTP
- 6-card Charlie vs none -> +0.177 pp
- Perfect play means choosing the highest-EV legal action in every situation.
- Use the ruleset switch to compare Duel Internal, Rainbet Internal, Duel Live Blackjack, Evolution Blackjack, Pragmatic VIP, and Evolution Infinite Blackjack.
- Duel Internal is modeled as infinite-deck, so its chart is exact for that ruleset. Finite-deck rooms like Rainbet can have tiny composition-dependent EV differences, but the chart remains the right practical guide.
Perfect Strategy Chart - Duel Internal Blackjack
Ruleset: Duel Internal Blackjack | Decks: infinite | Action selection: highest legal EV
The house edge is calculated as the negative of the player’s expected return under perfect play.
For every possible initial deal, the model computes the exact expected value of each legal action, including all future draw paths and dealer outcomes, weighted by their probabilities.
The highest-EV action is selected for that state.
Those optimal expected values are then averaged across all possible initial deals, using each deal’s exact probability.
That weighted average is the player edge; the house edge is the same value with the sign reversed.
Example: Rainbet Internal is about 0.4910% house edge on exact optimal play and about 0.5019% on the chart/basic-strategy abstraction.
So a 0.57% house edge means that, on average, the player loses 0.57 units for every 100 units of initial wager over the long run, assuming perfect play.
VOLATILITY / STD
Per-hand volatility from the exact perfect-play model is:
House Edge Calculator
0 precomputed configs
Change rules and see the modeled edges for the selected rule set.
Loading house edge matrix...
Insurance
Insure yourself against BJ, if the dealer has a BJ, then you won't lose your bet. Insurance is a very low variance high edge bet, it’s better to skip it.
8 decks configuration.
PAYOUT TABLE
- Decks: 8
- Insurance Win: 2 to 1
MODELED METRICS
- Edge: 7.4699%
- STD: 1.3855
21+3
Use your two cards plus dealer card to make your hand.
8 decks configuration.
PAYOUT TABLE
- Decks: 8
- Suited Trips: 100 to 1
- Straight Flush: 40 to 1
- Three of a Kind: 30 to 1
- Straight: 10 to 1
- Flush: 5 to 1
MODELED METRICS
- Edge: 3.7039%
- STD: 3.9830
Perfect Pairs
Form a pair using your two cards.
8 decks configuration.
PAYOUT TABLE
- Decks: 8
- Perfect Pair: 25 to 1
- Colored Pair: 12 to 1
- Mixed Pair: 6 to 1
PAIR TYPES
- Perfect Pair — same rank and same suit (identical card from another deck).
- Color Pair — same rank, same color (different suits; e.g., hearts + diamonds or clubs + spades).
- Mixed Pair — same rank, different colors (one red, one black).
MODELED METRICS
- Edge: 4.0964%
- STD: 3.9534
Blackjack Side Bet
Honey Bonus
Use your two cards plus dealer card to make your hand.
8 decks configuration.
PAYOUT TABLE
- Decks: 8
- Three of a Kind: 20 to 1
- Straight: 10 to 1
- Flush: 5 to 1
- Suited Blackjack: 3 to 1
MODELED METRICS
- Edge: 13.5101%
- STD: 2.8092
First Casino
Live Economics
House edge: 0.570%
House Edge after Rakeback: 0.000%
STD: 1.13
Max Possible Win: 4.00x
Second Casino
Live Economics
House edge: 0.570%
House Edge after Rakeback: 0.570%
STD: 1.13
Max Possible Win: 4.00x
Shared Session