Blackjack Blackjack
A card game where the goal is to make a total closer to 21 than the dealer without going over 21. Players choose whether to take more cards, so the house edge changes depending on your choices.
| English | Blackjack |
|---|---|
| Classification | Basics & Betting Terms |
| Category | Card table game (house-banked) |
| Also known as | 21, Vingt-et-un |
| Goal | A higher total than the dealer without going over 21 |
| Blackjack payout | 3:2 (some tables reduce it to 6:5) |
| House edge | Roughly 0.5-1% with basic strategy |
| Basic strategy first published | 1956 (Baldwin and 3 others) |
Overview
Blackjack is a card game where you play one-on-one against the dealer. The goal is to get a card total closer to 21 than the dealer without going over 21. It is also called “21.” In most casino games you just wait for the result, but in blackjack you decide whether to take another card or stop. That means the house edge can change at the same table depending on how you play.
Basic Rules
- Cards 2 to 10 count as their face value, and J, Q and K are worth 10. An Ace counts as 1 or 11, whichever is better for your hand.
- If your first two cards total 21 (an Ace and a 10-value card), it’s a “blackjack.” It usually pays 3:2, and if the dealer also has blackjack, it’s a push.
- If your total goes over 21, you “bust” and lose right away.
- The dealer must keep drawing until the total reaches 17 or more. Whether the dealer stands or hits on soft 17 (a 17 counting an Ace as 11) depends on the table.
- A regular win without a blackjack pays 1:1.
Your Options
| Option | Meaning |
|---|---|
| Hit | Take one more card. |
| Stand | Stop at your current total. |
| Double Down | Double your bet and take exactly one more card. |
| Split | If your first two cards have the same value, split them into two hands and place the same bet again on the second hand. |
| Surrender | Give up the hand and lose half your bet. Only some tables allow this. |
| Insurance | A side bet on the dealer having blackjack, offered when the dealer shows an Ace. It pays 2:1, but it loses money over the long run, so basic strategy doesn’t use it. |
Rules Change the House Edge
Even if you always make the mathematically best choice, known as “basic strategy,” the house edge usually stays around 0.5-1%. But each small rule detail moves this number.
| Rule Change | House Edge Effect |
|---|---|
| Blackjack payout 3:2 → 6:5 | About 1.4 percentage points higher |
| Blackjack payout 3:2 → 1:1 | About 2.3 percentage points higher |
| Dealer hits soft 17 → stands | About 0.2 percentage points lower |
| No doubling after split | About 0.12 percentage points higher |
| Number of decks (same rules) | 1 deck 0.16%, 2 decks 0.46%, 6 decks 0.64%, 8 decks 0.66% |
Wizard of Odds calculated a house edge of 0.28% under player-friendly Las Vegas rules, such as the dealer standing on soft 17 and surrender being allowed. On the other hand, a 6:5 payout table may look similar, but the expected result gets much worse (see expected value).
A Short History
Blackjack comes from a family of old card games that aim for “21.” “Veintiuno (21)” first appears in a novel written by Cervantes in 1601-1602, and rules for “Vingt-et-un” were published in England in 1800. The name “blackjack” has been used since around 1899. In 1956, Baldwin and three others published the first mathematically correct basic strategy, and mathematician Edward Thorp popularized card counting with his 1962 book “Beat the Dealer.” Casinos began adding more decks and changing rules around that time. For ways to adjust your bet from hand to hand, see Betting Systems, and for terminology, see General Casino Terms.