Blackjack is the thinking player's casino game. Unlike slots, your decisions directly change the odds, and with correct basic strategy the house edge drops to roughly 0.5% - among the best odds on any casino floor. Learn the rules, memorize a handful of strategy rules, and you turn a game of luck into a game of skill.
The rules
The goal is simple: build a hand that totals closer to 21 than the dealer's without going over. Cards 2 through 10 are worth their face value, face cards (J, Q, K) are worth 10, and an ace is worth 1 or 11 - whichever helps your hand. A "blackjack" is an ace plus any ten-value card on your first two cards, and it typically pays 3:2.
You and the dealer each start with two cards. The dealer shows one card face up. You then choose how to play your hand:
- Hit: Take another card.
- Stand: Keep your current total.
- Double down: Double your bet and take exactly one more card.
- Split: If you have a pair, split into two separate hands with a second bet.
- Surrender: Where offered, forfeit half your bet to fold a bad hand.
The dealer plays last by a fixed rule - usually hitting on 16 or less and standing on 17 or more. Whether the dealer hits or stands on a "soft 17" (an ace plus a six) matters: dealer standing on all 17s is slightly better for you.
The 3:2 rule - avoid 6:5 tables
Always confirm blackjack pays 3:2, not 6:5. A 6:5 payout on naturals adds roughly 1.4% to the house edge, wiping out every advantage that good strategy gives you. If a table pays 6:5, walk away and find a 3:2 game.
The odds and house edge
With basic strategy on a standard game, the house edge is about 0.5%, meaning you lose roughly 50 cents per $100 wagered over time. Rule variations move that number:
| Rule | Effect on house edge |
|---|---|
| Blackjack pays 3:2 | Baseline (good) |
| Blackjack pays 6:5 | +1.4% (bad) |
| Dealer stands on soft 17 | -0.2% (good for you) |
| Dealer hits soft 17 | +0.2% (bad for you) |
| Double after split allowed | -0.14% (good for you) |
| Single deck | -0.48% (good for you) |
| Eight decks | +0.02% vs single deck |
Basic strategy
Basic strategy is the mathematically optimal decision for every combination of your hand and the dealer's up card. It has been solved by computer simulation and never changes. Here are the core rules that cover most situations:
Hard totals (no ace, or ace counted as 1)
- Always stand on hard 17 or higher.
- Stand on 13-16 when the dealer shows 2 through 6 (the dealer's "bust cards").
- Hit 12-16 when the dealer shows 7 or higher.
- Always hit 11 or lower (double on 11, and on 10 vs dealer 9 or lower).
- Double down on 9 against a dealer 3-6.
Soft totals (ace counted as 11)
- Always stand on soft 19 (A-8) or higher.
- Double soft 13-18 against a dealer 5 or 6 where allowed, otherwise hit.
- Hit soft 17 (A-6) or lower against strong dealer cards.
Pairs - split or not
- Always split aces and 8s.
- Never split 10s (a 20 is already a winning hand) or 5s (treat as a 10 and double).
- Split 2s, 3s, 6s, 7s and 9s only against weaker dealer up cards.
Insurance and side bets
When the dealer shows an ace you may be offered insurance. Decline it - insurance carries a house edge of around 7% and is a losing bet for anyone not counting cards. Most side bets (21+3, Perfect Pairs) look tempting but carry house edges of 2% to over 5%. Stick to the main game.
Bankroll and reality check
Even played perfectly, blackjack still has a small house edge, so you will lose over a long enough stretch. Set a session budget, bet a small fraction of your bankroll per hand, and never chase losses. Card counting can flip the edge to the player, but it is difficult, and online games shuffle continuously, which neutralizes it - so counting is not a viable online strategy. Live dealer blackjack, covered in our live dealer guide, uses real cards but still reshuffles frequently.
Blackjack rewards discipline more than any other casino game. Learn the strategy, avoid the sucker bets, and you will get more play from every dollar. Ready to play? Compare vetted operators on our best online casinos page, and keep our responsible gambling tools handy.