Blackjack is played against the dealer, not other players: you win by getting a hand closer to 21 than the dealer’s without going over. A hand totalling more than 21 is a bust and loses at once. On a standard table a winning hand pays even money, a natural blackjack pays 3 to 2, and the house keeps a small edge of about 0.4% when you follow basic strategy.
This guide covers the rules as set out in New Jersey’s casino regulations, which are public and detailed, plus the rule changes that move the odds the most. The edge figures come from our own simulation of 200 million hands per rule set. Blackjack is a casino game with a real cost, so the cost section below matters as much as the rules.
How do you play blackjack: what is the goal?
The goal is a hand worth more than the dealer’s hand without going over 21. Cards 2 to 10 count at face value, jack, queen and king count 10, and an ace counts 11 unless that would bust the hand, in which case it counts 1, according to N.J.A.C. 13:69F-2.2.
That ace rule gives two kinds of hand:
- Hard hand: no ace, or an ace that must count 1. A hard 16 is, for example, 10 and 6.
- Soft hand: an ace counting 11. An ace and 6 is a soft 17, and you cannot bust with one more card, because the ace can drop to 1.
You beat the dealer in three ways: your total is higher, the dealer busts, or you hold a natural (an ace plus a ten-value card as your first two cards) and the dealer does not.
How does a round of blackjack work?
Each round follows the same order. You place a bet, receive two cards, see one dealer card, then choose how to play your hand before the dealer plays theirs.
- Bet. Place your wager in the betting area before any cards are dealt.
- Deal. You and the dealer each get two cards. One dealer card is face up (the upcard) and one is hidden.
- Check for naturals. If you hold a natural and the dealer does not, you are paid 3 to 2 on your bet. If both have one, it is a push and you keep your bet.
- Play your hand. Hit, stand, double, split or take insurance, as described below.
- Dealer plays. The dealer reveals the hidden card and must follow fixed rules. On most tables the dealer typically draws on 16 or less and stands on every 17 (called “stands on soft 17”), but some tables make the dealer hit a soft 17.
- Settle. Winning hands are paid even money, ties push, and busted or lower hands lose.
The dealer has no choices. That fixed rule is why a strategy chart can exist at all.
What can you do with your hand?
You have up to five options, and not all are available every time. The names are the same at every table.
- Hit: take another card. You may keep hitting until you stand or bust.
- Stand: keep your total and end your turn.
- Double down: place an extra bet up to the size of your original bet and receive exactly one more card. New Jersey’s doubling rule says one and only one additional card is dealt, and doubling is not allowed on a natural.
- Split: if your first two cards have the same value, you can put up an equal second bet and play two separate hands. Under N.J.A.C. 13:69F-2.11, split aces receive only one card each, and a casino may allow up to three re-splits at some tables.
- Insurance: when the dealer shows an ace you may bet up to half your original wager that the dealer has a ten-value card underneath. It pays 2 to 1.
Insurance is the one option most strategy guides tell beginners to skip, and the maths below shows why.
What is basic strategy, and how much does it save?
Basic strategy is the mathematically best play for every combination of your hand and the dealer’s upcard. It cannot make blackjack a winning game, but it cuts the house edge to about 0.4% on a common six-deck, 3 to 2 table.
You do not need a full chart to start. These rules cover most hands:
- Hard 17 or more: always stand.
- Hard 12 to 16: stand if the dealer shows 2 to 6, hit if the dealer shows 7 or higher.
- Hard 11: double against most upcards.
- Soft 17 or less: hit, or double against a weak dealer card.
- Aces and 8s: always split.
- Tens and 5s: never split. Treat 5 and 5 as a hard 10, and keep 20.
The reasoning is that the dealer busts most often when showing a 2 to 6, so you take fewer risks and let the dealer fail. When the dealer shows a 7 or higher, a dealer total of 17 or more is likely, so you must try to improve a stiff hand.
What are the odds in blackjack?
The odds depend on the table rules more than anything else. We simulated 200 million hands per rule set with a close-to-basic-strategy player, with doubling after splits and re-splitting allowed. The results are in the table below, and the margin of error is under 0.01 percentage points.
| Table rules | House edge |
|---|---|
| Two decks, dealer stands on soft 17, blackjack pays 3 to 2 | about 0.27% |
| Six decks, dealer stands on soft 17, blackjack pays 3 to 2 | about 0.43% |
| Eight decks, dealer stands on soft 17, blackjack pays 3 to 2 | about 0.43% |
| Six decks, dealer hits soft 17, blackjack pays 3 to 2 | about 0.64% |
| Six decks, dealer stands on soft 17, blackjack pays 6 to 5 | about 1.79% |
| Six decks, dealer hits soft 17, blackjack pays 6 to 5 | about 2.00% |
| Six decks, dealer stands on soft 17, blackjack pays even money | about 2.70% |
Three lessons stand out:
- Check the blackjack payout first. A 6 to 5 table costs you about 1.4 percentage points more than a 3 to 2 table, which is more than every other rule here combined. Over 100 hands at $10, that is roughly $14 extra expected loss.
- Soft 17 matters. When the dealer hits a soft 17, the edge rises by about 0.2 percentage points.
- Fewer decks help a little. Two decks lower the edge by about 0.16 points compared with six.
A natural blackjack arrives in about 4.7% of hands on a six-deck shoe. On a single deck it is 4.83% (128 of the 2,652 possible two-card deals).
Why do guides say never take insurance?
Insurance is a side bet that the dealer’s hidden card is a ten-value card. It pays 2 to 1, so it is only fair if the dealer has a ten-value card exactly one time in three.
Once the dealer’s ace is showing, 16 of the 51 unseen cards in a fresh single deck are ten-value, which is 31.4%, just under one in three. On that deck insurance loses about 5.9% of the amount staked, because 2 times 16 minus 35, divided by 51, is negative. In a six or eight-deck shoe the ten-value share is 30.8%, and the loss is about 7.5%. Either way it is a worse price than the main hand carries.
What are the most common blackjack mistakes?
Most losses beyond the built-in edge come from avoidable choices. The usual ones:
- Playing 6 to 5 tables. They look the same and cost far more.
- Taking insurance or “even money” on a natural when the dealer shows an ace. Even money is the same bet as insurance.
- Standing on 12 to 16 against a strong card because hitting feels risky. Mathematically, standing loses more often.
- Splitting tens. Twenty is a strong hand and splitting breaks it.
- Chasing losses by raising bets. No betting system changes the house edge. The edge is a percentage of every bet, so larger bets lose more.
- Using side bets such as pairs or 21+3. These carry higher house edges than the main game.
Card counting is outside the scope of this guide.
What does blackjack really cost to play?
Blackjack costs the house edge times the amount you wager, plus any time spent at the table. At a 0.43% edge, 100 hands at $25 means $2,500 of total bets and an expected loss of about $10.75. At a 6 to 5 table the expected loss for the same play is about $44.75.
Those are averages. In a real session the result swings far from them, and a bad run can cost much more than the expected figure. Set a limit before you sit down, decide what you will spend, and leave when you reach it. Our guide to setting a gambling budget and time limit shows how, and the Safer play toolkit lists tools and support. If gambling is causing you harm, visit our get help page.
Laws on gambling vary by country and state. Check that a game is legal and licensed where you live before you play.
Where should you go next?
Practice with play money or a deck of cards at home until the basic strategy rules feel automatic. When you want to compare, read about craps and baccarat, two other table games with small published edges. If you prefer playing against other people, Texas Hold’em has no house edge in a private game, though the stakes are still real money.