How insurance works
You can bet up to half your original stake. If the dealer has a 10-value card underneath, insurance pays 2 to 1. If not, you lose the insurance bet and the hand continues normally.
The maths
A 2 to 1 payout only breaks even if the dealer has blackjack at least one time in three, or 33.3% of the time. In a multi-deck shoe, the chance that the hole card is worth 10 is only about 31%. That gap gives the house an edge of roughly 7% on the insurance bet, much more than on the main game.
What about “even money”?
When you have blackjack and the dealer shows an ace, you may be offered even money. It's exactly the same as taking insurance on your blackjack, with the same disadvantage. Over time, declining it pays more.
The only exception
Card counters sometimes take insurance when the remaining shoe is rich in 10s. For everyone else, and in online games that reshuffle every hand, the answer is simple: never take insurance.
FAQ
Does insurance protect my bet?
No. It's a separate side bet with a house edge of about 7%. It pays only when the dealer has blackjack.
Should I take even money with blackjack?
Basic strategy says no: even money is insurance in disguise and loses value over time.
Related guides
Strategy and maths reduce the house edge, but never remove it. 18+, play responsibly.