Double Exposure and other blackjack variants

Every blackjack variant follows the same design: give the player something visible, such as both dealer cards, free doubles, bonus payouts or a five-card win, and take it back with a rule that is worth more than it looks, such as even-money blackjacks, dealer-wins-ties or push-22. Wizard of Odds’ rule-variations table prices the common ingredients, and the games below are what casinos have built from them.

Double Exposure

The dealer’s two cards are both dealt face up. Richard A. Epstein proposed the game in 1977, and Wikipedia records that it first appeared in 1979 at Bob Stupak’s Vegas World in Las Vegas with rule changes that favoured the house; it is also known by the German name Zweikartenspiel. The compensating rules are severe:

In ordinary blackjack Wizard of Odds values “player loses 17–21 ties” at 8.86 points to the house and “blackjacks pay 1 to 1” at 2.27 points. Knowing the dealer’s hand is worth more than both combined, which is why the game can still land under 1%. Wizard of Odds’ measurements of real rule sets:

The rule effects within the game, per Wizard of Odds: dealer stands on soft 17 is worth 0.39 points to the player; double after split 0.32; a tied blackjack winning for the player 0.22; splitting limited to once costs 0.71; doubling limited to 9–11 costs 1.04 and to 10–11 costs 1.44. The doubling restriction is far more expensive here than in ordinary blackjack (0.09 and 0.18) because doubling against a known dealer stiff is the game’s main weapon.

Strategy is entirely different from blackjack, since you play against a known total rather than an upcard. Against a dealer stiff that must be hit you stand on every stiff of your own and double far more freely; against a dealer 20 you must hit anything below 20, because standing cannot win; and the tie rule means a dealer 17 must be beaten, not matched, so you hit a 17 against it. Wizard of Odds publishes separate charts for S17 and H17 games, and notes one bonus-driven exception at the former Lady Luck game. The game is now rare in Las Vegas.

Super Fun 21

Super Fun 21 was patented by Howard F. Grossman in 1999 and is dealt from one, two or six standard 52-card decks with the dealer hitting soft 17. It trades the blackjack premium for a long list of options and bonuses. From Wizard of Odds:

Wizard of Odds’ simulated house edge with a cut card and basic strategy: 1.16% for one deck, 1.30% for two and 1.40% for six. All three are worse than a 3:2 single-deck or six-deck game with ordinary rules, though better than any 6:5 game. The even-money blackjack (2.27 points in ordinary blackjack, partly offset by the diamond bonus) is simply larger than the sum of the bonuses.

Strategy follows the number of cards in your hand, as in Spanish 21: a four-card hand with a shot at a six-card 20 or a five-card 21 is hit far more readily than its total suggests. Wizard of Odds’ one firm rule for the double-down surrender is to use it on a doubled 12 to 16 against a dealer 8 through ace and on a doubled 17 against an ace. Some descriptions, including Wikipedia’s, list the blackjack payout as 6:5 rather than even money; the Wizard of Odds analysis and the figures above assume even money with 2:1 for diamonds, so confirm the payout at the table. A side bet paying 300:1 on a diamond blackjack on the first hand after a shuffle, reported in San Diego County casinos, carries a 9.2% house edge.

Blackjack Plus

Blackjack Plus is a New Zealand game also reported at Crown Melbourne; Wizard of Odds describes its Australian rules as an unconfirmed report based on a Crown rules document. The player-facing attractions are a five-card Charlie (any unbusted five-card hand wins automatically) and an automatic win on any 21. The compensating rule is push-22: when the dealer’s hand totals 22, every player hand still standing is a standoff. The game is dealt without a hole card, with settlement under the Australian OBBO rule (busted bets plus one original bet per remaining hand) described in Pontoon and Australian blackjack.

Reported rule differences between the two versions:

Wizard of Odds’ analysis of the rules it examined gives a house edge of 6.36%, and the page notes a separate online claim of 5.5% for a Melbourne rule set. Both are far above any other game on this page: push-22 is worth 6.91 points in ordinary blackjack, and a five-card Charlie (1.46) plus automatic 21s (0.54) do not pay for it when blackjack is also cut to even money. The page attaches no figure to the 3:2 Australian version; treat the game as expensive unless a published analysis of the exact rules says otherwise.

Pricing a variant yourself

The rule-variations table lets you sanity-check any new game before sitting down. The expensive compensating rules, as measured in ordinary blackjack:

And the common gifts:

If a game takes one item from the first table and gives back two or three from the second, the gifts rarely cover it; the games that work, such as Blackjack Switch and Free Bet Blackjack, add a structural advantage worth several points on its own. The sums are approximate because of interaction effects, and each variant needs its own strategy, which most players do not learn. Blackjack World Tour is a free iOS blackjack game played with virtual chips; it is a social casino with in-app purchases and no real-money gambling. The variants above are real-money casino games whose published edges assume correct variant-specific strategy.

Related reading

• How rule variations change the house edge
• Blackjack Switch
• Spanish 21
• Side bets explained