Blackjack

Overview

Beat the dealer's hand without exceeding 21. The rules are simple; the edge lives in the details, and those details vary between tables.

Each casino sets its own rules, within what its gaming regulator approves: decks, payouts, table limits and options vary. Check the rules at your table. The odds below are our own calculations.

1. Card values

Card	Value
2–10	Face value
Jack, Queen, King	10
Ace	1 or 11, whichever helps

A hand containing an ace counted as 11 is soft — it cannot bust on the next card. Once the ace must count as 1, the hand is hard.

Blackjack is an ace with any ten-value card on the first two cards. It beats any other 21 and normally pays 3 to 2.

2. Play

Each player is dealt two cards face up. The dealer takes one up and one down.

Players act in turn:

Action	Meaning
Hit	Take another card
Stand	Take no more
Double down	Double your bet, take exactly one more card
Split	Two cards of equal rank become two hands, with a matching bet
Surrender	Forfeit half your bet and fold — not offered everywhere

Exceed 21 and you bust, losing immediately regardless of what the dealer does afterwards.

3. The dealer

The dealer has no choices. They follow a fixed rule, printed on the felt:

• Hit on 16 or less, stand on 17 or more.
• Some tables hit on soft 17, an ace counted as 11 plus a six, which is slightly worse for the player.

That absence of judgement is the whole structure of the game: you are playing against a machine with a published algorithm.

4. Payouts

Result	Pays
Win	1 to 1
Blackjack	3 to 2
Push (tie)	Bet returned
Insurance	2 to 1

Avoid 6-to-5 blackjack tables. You're dealt a blackjack about 4.7% of the time, so paying 6 to 5 instead of 3 to 2 costs you about 1.4% of every bet. It's the most important thing to check before sitting down.

5. Insurance

When the dealer shows an ace, you may buy insurance for half your stake, paying 2 to 1 if they have blackjack.

It is a bad bet. With an ace showing, the dealer's hidden card is a ten-value card about 4 times in 13 (30.8%). Insurance pays 2 to 1, so it loses about 7.7% of what you stake on it. Decline it.

6. Basic strategy

The best play for every hand against every dealer card can be calculated. The exact chart depends on the table's rules, so casinos and books publish charts for each set of rules. A few points hold across them:

• Hit hard 11 or lower: you can't bust.
• Stand on hard 17 or higher.
• Stand on hard 13–16 when the dealer shows 2–6, because the dealer is more likely to bust. Hard 12 is closer: hit against a 2 or 3.
• Split aces and eights. Don't split tens or fives.

Commonly argued

• Blackjack should pay 3 to 2. Check the felt.
• Insurance is a losing bet, always.
• You do not have to beat 21 — you have to beat the dealer without exceeding it.
• A bust loses immediately, even if the dealer busts afterwards.
• The dealer has no choices at all.
• Five cards under 21 isn't an automatic win in casino blackjack. That's a home rule.