- The game is with one, two, or six decks.
- Dealer usually hits a soft 17.
- Player may double after a split.
- Player may resplit to up to four hands, including aces.
- Player may hit and double down to split aces.
- Player may double on any number of cards.
- Player may take late surrender on any number of cards.
- Player may surrender half of total bet after doubling, what is called "Double Down Rescue" in Spanish 21.
- A player hand totaling 20 or less, consisting of six cards or more, except after doubling, automatically wins.
- A player hand of 21 points, consisting of 5 cards or more, except after doubling, pays 2 to 1 instantly.
- A player blackjack always wins
- A player blackjack in diamonds pays 2 to 1, all other blackjacks pay even money.
Single Deck Strategy
Double Deck Strategy
Double Down Surrender Strategy: The player should surrender after doubling down with either (1) 12 to 16 and the dealer has an 8 to ace, or (2) 17 and the dealer has an ace.
The following house edge figures are random simulation based, assuming a cut card and using the basic strategies above.
I have had two unconfirmed reports of a side bet in Super Fun 21, found in the casinos of San Diego county. The bet pays 300 to 1 on a suited blackjack in diamonds. It is only available on the first hand after a shuffle.
In a single-deck game the probability of winning is 0.3%, and the house edge is 9.2%.