Veteran blackjack players are familiar with a number of rules that vary from casino to casino, or even from table to table in the same casino.
Variations in whether the dealer hits soft 17, how many times players can split pairs, on which two-card totals players may double down, whether blackjacks pay 3-2 or 6-5, and the number of decks in play are common in online casinos and in live blackjack alike.
Beyond those variations, there's a set of rare rules such as automatic payoffs on any player 21, five-card Charlies, double downs on more than two cards and even the size of a deck.
You won't see these rules often in regular blackjack games, but if you do, they have a big impact on blackjack strategy and odds.
More often, you'll see them in blackjack-based games such as Spanish 21 and Super Fun 21. Those trade off a few negative rules for the opportunity to use player-friendly options to make an interesting, fun game.
Let's check out some of those less common blackjack rules and how they affect the game.
Blackjacks pay only even money
Compared to full 3-2 returns on two-card 21s, paying 1-1 tacks a whopping 2.27% onto the house edge. Given that the house edge against a basic strategy player is usually less than 1%, that's an enormous swing.
You wouldn't want to play a regular blackjack game with even-money blackjack pays. But using this rule is why Super Fun 21 can allow players to double down on any number of cards along with other positive rules and why all dealer cards can be dealt face up in Double Exposure Blackjack.
The hike in house edge from the low blackjack payoff is largely offset by player gains on other rules.
Decks of only 48 cards, with 10-spots removed
Spanish 21 uses a so-called "Spanish" deck where the only 10-value cards are Kings, Queens, or Jacks.
That decreases the frequency of blackjacks. If your first two cards include an Ace, there are fewer 10-value cards available to complete a two-card 21.
Double downs also are affected. If you have a two-card total of 11, fewer 10-value cards means your draw will bring you to 21 less often.
That's a big negative for the player, but Spanish 21 offsets that by making winners of all player 21s, even if the dealer also has 21. Player blackjacks beat dealer blackjacks and players may double on any number of cards. Players may hit multiple times or double down after splitting Aces; and in a "double down rescue" feature, players may surrender and lose only their original bet if they get a bad card after doubling down.
That adds a lot of fun and intrigue for players, but they have to pay the price extracted by the Spanish decks.
House wins all ties
This is a Godzilla among negative rules, adding 8.86% to the house edge. You'll see it mainly in Double Exposure Blackjack and it has a huge impact on strategy.
If you know the dealer's first two cards total 20, you also know you have to hit if you have a 20. There's no settling for a push.
A "Charlie" is a hand of a designated number of cards that total less than 21, so that a five-card Charlie is a non-busted hand of five cards and a six-card Charlie is six cards totaling 21 or less.
When such a rule is in place, a Charlie brings an automatic payoff. Even money payouts on five-card Charlies reduce the house edge by 1.46%.
That's a huge swing, so needless to say, you rarely see it. Super Fun 21 has variations in which six cards totaling 20 or less make an even-money winner, or five-cards totaling 21 pay 2-1 regardless of dealer hand. Those are among the rules made possible by paying only even money on blackjacks.
Those who learn to play in home games sometimes are surprised to find Charlies usually aren't part of casino blackjack. Playing in Las Vegas, I once sat next to a player who held up a game by loudly insisting he be paid on his Charlie. Supervisors and the dealer had to work together to calm the player down and explain Charlie really didn't live there.
Blackjacks pay 2-1 or suited blackjacks pay 2-1
In rare cases, casinos have been known to offer big blackjack payoffs as a promotion. One Illinois casino offered 2-1 pays on all blackjacks and found big money players from all over the country crowding the tables. The game was shut down in less than a day.
Paying 2-1 on blackjack adds 2.27% to the player side, and that's more than enough under most rules to give players an edge on the overall game. If both cards have to be on the same suit, 2-1 payoffs decrease the house edge by 0.57%, still a big gain for players.
Player 21 is an automatic winner
If any player wins regardless of the dealer total, it knocks 0.54% off the house edge. How big is that? In a six-deck game in which the dealer hits soft 17, you're allowed to:
- double down on any first two cards
- double after splitting pairs
- split pairs up to three times
The house edge against a basic strategy player is 0.62% in this scenario. Paying all player 21s would knock that edge to less than a tenth of a percent.
Needless to say, you'll see this rule only in blackjack derivatives with a significant rule favorable to the house.
Players may double down on any number of cards
Imagine the dealer has a 4 up and you start a hand with a 2 and a 3, draw a 4 for a total of 9, then draw 2 for 11.
In regular blackjack, you hit once more and hope for the best. But in Super Fun or Spanish 21, you can double down on any number of cards. That decreases the house edge by 0.23%.
Player may draw to split Aces
Blackjack regulars know the drill. If you split Aces, you get one card on each Ace, and that's it. No additional draws
If you can draw or double down with split Aces, it reduces the house edge by 0.19%. That's a nice boost for players in Spanish or Super Fun 21.
Double Down Rescue
This is a variation on surrender available in Spanish 21. If you double down and don't like your draw. you can call for the rescue. You lose only your original bet and not your double. That reduces the house edge by 0.1%.
The list of potential rare rules can go on for dozens of variations, but you get the idea. Rules that add extra payoffs or give players extra options reduce the house edge, sometimes dramatically. Those that reduce payoffs or eliminate player options pad the edge for the house.
Creative game designers find ways to incorporate these rare options to make a game that's fun to play. Enjoy, but beware the downside of the big negative rules.