I think the insurance bet in blackjack is a side wager players can place when the dealer shows an Ace, allowing them to bet half their original wager that the dealer has a blackjack. If the dealer does, the payout is 2 to 1; if not, the bet is lost. While players might use this bet if they suspect the dealer has a blackjack, it is generally recommended to avoid it, as it tends to have a higher house edge and is not favorable in the long run.