The Five Essential Blackjack Rules That Can Make Or Break Your Session

Blackjack dealer at a casino

With the possible exception of video poker, blackjack is among the most complex games offered by casinos.

Graduating from a ploppy who plays a 95% game, to a pro that can eke out a 1% edge can take months of dedication. In our minds, one of the first steps on that cold and lonesome journey entails recognizing which blackjack rules are the most favorable for the player, and which belong in the dumpster.

Problem is, take a stroll down the Las Vegas Strip and you’re likely to find dozens of different blackjack rulesets, ranging from awesome 3:2 double-deck games that allow doubles on any two cards and after splits, to games even Big Wheel players might think twice about.

Compounding matters, some rules have a far more significant impact on the casino’s house edge than others. Listed below are the ones we value the most.

Blackjack pays 3:2 vs. 6:5

This one is a no-brainer: if a blackjack game pays out 6:5 on naturals, run for the hills.

The difference between winning 12 or 15 bucks on a $10 blackjack might not seem like a lot given the relative infrequency of blackjacks, but this singular rule adds approximately 1.4% to the house edge.

For a game where the house edge typically runs between 0.25 – 1%, that’s enormous, and you should tell that casinos to shove it. Take your business elsewhere.

Luckily, this is among the easiest rules to recognize, as blackjack payouts are typically plastered across the felt. Make sure to read the not-so-fine print before taking a seat, kids. To get you started, 6:5 games are most commonly spread at Strip casinos, in the low-level pits.

The number of decks

Here’s where it gets a bit tricky, as other blackjack rules have a fairly similar positive or negative impact on the house edge.

We’d say the second most impactful rule has got to be the number of decks dealt. The difference between a single-deck game and eight-deck shoe is pretty egregious, hovering right around 0.5%.

Again, this is a pretty easy one to identify. If the game is hand dealt, and the player’s cards are pitched face down, it’s always single- or double-deck. Definitely take a moment to figure out if it’s single-deck, as the house edge will be markedly lower.

Although there are a few exceptions to this next rule, generally speaking, if a game is dealt from a shoe, then you’re looking at a six- or eight-deck game. Unless you’re a professional card counter, we wouldn’t obsess over the exact number of decks, as the difference in house edge between a six- and an eight-deck game is pretty negligible (~0.02%). We’ll forgive you if you’re wrong.

Whatever you do, never, ever judge a game’s merit on the number of decks alone, as single-deck games are notorious for having garbage rules, and the rulesets for other games vary widely. You might think that a shoe player is a sucker, but that sucker is you if you’re playing a 6:5 double-deck game, and he’s playing 3:2.

Dealer hits or stands on soft 17

Here’s another one that you wouldn’t think would have a tremendous impact on a game’s EV, but is the third most damaging common rule we’ve studied.

If the dealer takes a hit on 17 (h17), the house edge increases by about 0.22% on eight-deck shoe games, and a tad less on single- and double-deck games. Yea, that’s right, all it takes is the dealer taking a swipe on a pretty rare hand to impact your return by 22 cents for every $100 wagered.

Remember, that in blackjack, 17 is considered a losing hand. By taking a hit, the dealer has a chance to either improve their hand directly (Ace, two, three, four), keep the same hand (Ten, Jack, Queen, King), or buy themselves another shot at a winner (five, six, seven, eight, nine). That’s eight out of 13 times where the dealer will either shoot par or improve directly, and the remaining five out of 13 scenarios do not immediately result in a bust.

Luckily, this is another rule that is usually indicated on the felt. Unfortunately, there’s no strong correlation between h17 and the number of decks used: We’ve witnessed plenty of shoe games with h17, and a decent number of double-deck games where the dealer shuts it down on an Ace-six.

Double on any two

Another dreadful rule that has infiltrated blackjack tables is only allowing players to double down on 9-11, or even worse, on 10 and 11 only.

While this is mostly a single- or double-deck rule, in recent years we’ve seen casinos like Caesars Palace stamp this atrocity on its shoe games. The difference in house edge isn’t huge (-0.09% for 9-11 and -0.18% for 10,11) but it has intangible effects, like completely sucking the fun out of playing the game of blackjack. Way to go Caesars.

In any case, avoid double-deck and shoe games with this rule like the plague. The way to tell (sometimes) is that 9-11 and 10,11 games typically indicate as such on the felt, whereas games that allow doubles on any two don’t. This isn’t a universal rule, so if you don’t know, ask.

Double after split

We’re not going to get into games that don’t allow splits at all, because we just haven’t seen any. Contact your state’s gaming regulator if your local casino spreads this game, and ask that they be shut down immediately.

Instead, we’ll take a look at whether a game allows players to double down after they split. Put simply, a good game allows this, and a poor one does not. The difference in house edge is roughly 0.14% for this rule, assuming double downs on any two cards. That isn’t tremendous, but when stacked with other poor rules, it can make for a nasty ride.

Other rules to consider

    • Resplits: There’s about a 0.1% difference between a game that allows one split and one that permits resplits up to four hands.
    • Late surrender: Shoe games that support this rule lose approximately 0.07% of their house edge. Good news for players.
    • Resplit Aces: This uncommon and very attractive rule subtracts about 0.08% from the casino’s advantage.

It’s important to remember that good rules often flock together, especially for double-deck and shoe games. If a game supports h17, and doesn’t allow doubles after splits, the other rules are probably going to suck it as well.

Likewise, a six-deck shoe game with late surrender and resplit aces will undoubtedly offer players the option to double on any two and resplit up to four hands.

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Written by Robert DellaFave
Robert DellaFave is the Head Chief of The EV Chief. Previously, he worked for a variety of gambling publications, but got tired of being yelled at by casino reps for being too honest. Hobbies include a healthy mix of advantage gambling and being a degenerate, and tending to his lovely 1-year old daughter.