Blackjack has the lowest house edge of any common casino game — but only if you play it correctly. Played on instinct, it is worse than roulette. Played with basic strategy, it is the best value on the floor.
The basics
Card values: numbers are face value, jacks, queens and kings are 10, and an ace counts as 1 or 11 depending on which helps you. A hand containing an ace counted as 11 is called soft — a soft 17 is ace plus six, and it cannot bust with one more card.
You are dealt two cards, the dealer takes two with one face up, and you decide what to do. Go over 21 and you lose immediately, regardless of what the dealer does afterwards. That asymmetry is the house edge in its entirety.
A natural blackjack — ace plus a ten-value card on the first two cards — normally pays 3:2.
Your options
- Hit — take another card
- Stand — keep your total
- Double down — double your stake and take exactly one more card
- Split — separate a pair into two hands with a second equal stake
- Surrender — forfeit half your stake and end the hand (not offered everywhere)
Basic strategy, condensed
Basic strategy is the mathematically optimal action for every combination of your hand and the dealer’s upcard. The full chart is worth learning; these rules cover most of the value:
Always:
- Split aces and eights
- Never split tens or fives
- Stand on hard 17 or higher
- Hit hard 8 or lower
Against a weak dealer upcard (2–6):
- Stand on hard 12–16 and let the dealer risk busting
- Double on 10 or 11
Against a strong dealer upcard (7–ace):
- Hit hard 12–16 — standing here is the most expensive common mistake in blackjack
- Hit soft 17 rather than standing
Never take insurance. It is offered when the dealer shows an ace and it pays 2:1 against roughly a 9:4 chance. It is a side bet with a house edge above 7%, and the fact that it is offered at a tense moment is not an accident.
Rule variations change the edge
Two tables that look identical can differ by more than a full percentage point:
| Rule | Effect on house edge |
|---|---|
| Blackjack pays 6:5 instead of 3:2 | +1.4% — avoid these tables entirely |
| Dealer hits soft 17 | +0.2% |
| Double after split allowed | −0.14% |
| Surrender allowed | −0.08% |
| Single deck rather than six | −0.5% |
The 6:5 payout is the one to watch. It is common on low-limit tables and it takes blackjack from the best game in the casino to a mediocre one. Check the felt or the game info panel before you sit down.
Card counting and online play
Card counting works in principle and does not work online. RNG blackjack reshuffles after every hand, so there is no count to keep. Live dealer tables use continuous shuffling machines or shuffle early, and casinos monitor bet-spread patterns. Treat counting as irrelevant to online play.
What does transfer is basic strategy, and unlike counting it is fully permitted. Nothing stops you keeping a strategy chart open beside the table.
Side bets
Perfect Pairs, 21+3, Lucky Ladies and similar side bets carry house edges between 3% and 10% — five to twenty times the main game. They are the casino’s compensation for offering blackjack at all. Skip them.
The realistic summary
Learn basic strategy, find a 3:2 table, never take insurance, ignore the side bets. Do those four things and you are playing the closest thing to an even game a casino offers.