Gambling terms, explained straight

Casino & Table Games

Insurance blackjack

A side bet in blackjack that players can place when the dealer's face-up card is an ace, betting that the dealer's hidden card is worth ten points and the dealer therefore has blackjack.

When offered
When the dealer's upcard is an ace.
Maximum bet
Up to half the player's original bet.
Payout
2 to 1 if the dealer has blackjack.
House edge
About 8% in a typical game; 5.9% in single-deck blackjack.23
Resolved
Immediately after the dealer peeks at the hole card.

Key points

  • Insurance is a side bet, not part of the main hand; it wins only if the dealer has a ten-value hole card and blackjack.
  • The bet pays 2 to 1, but the odds of the dealer having a ten underneath are less than 1 in 3 in a full deck, giving the house an edge of roughly 8%.2
  • Basic strategy recommends always declining insurance, regardless of the player's own hand, because the expected value is negative.1
  • When a player has blackjack and the dealer shows an ace, 'even money' is offered — effectively insurance that locks in a 1:1 payout instead of the usual 3:2.4
  • Card counters may take insurance when the remaining deck is rich in ten-value cards, as the bet can then have a positive expectation.5

Example of insurance in blackjack

You bet £10 and are dealt 8 and 5. The dealer shows an ace. You may place an insurance side bet of up to £5. You bet £5. The dealer peeks and turns over a king — blackjack. Your insurance bet wins at 2 to 1, paying £10. Your main £10 bet loses, so you break even on the round. If the dealer had not had blackjack, you would have lost the £5 insurance and played the hand as usual.

When to buy insurance in blackjack

For a player following basic strategy, the answer is never. The house edge on insurance is about 8% in a typical six-deck game, making it a poor bet in the long run.2 The only exception is for card counters who track the ratio of ten-value cards to others; when the deck is ten-rich, insurance can become a profitable wager.15

Common questions

When should you buy insurance in blackjack?

Basic strategy says never buy insurance, because the house edge is roughly 8% and the bet has negative expected value.2 The only exception is for card counters who know the remaining deck is rich in ten-value cards, making the bet profitable.5

Where this term is used

Not the same as

Sources

  1. Insurance in Blackjack - Just Say No! wizardofodds.com Defines insurance and explains why basic strategy says to decline it.
  2. Blackjack rules, part 2 - Wizard of Odds wizardofodds.com Gives the house edge figures for insurance in typical blackjack games.
  3. Single-Deck Blackjack Strategy wizardofodds.com Provides the single-deck house edge for insurance.
  4. Even money en.wikipedia.org Explains the even-money option as a variant of insurance.
  5. Card counting en.wikipedia.org Describes how card counters use insurance as a profitable play.

Sources are drawn from regulators, universities and published research, and each one is labelled with what it actually is — a preprint is not called a paper. Bookmaker and affiliate pages are never cited here, because a page that sells betting is not a neutral authority on it.