In blackjack, the "surrender" option allows a player to give up their hand and forfeit half of their bet instead of continuing to play. This option is usually available after the initial cards are dealt and before any further actions like hitting. There are two types of surrender: early surrender, where you forfeit your bet before the dealer checks for blackjack, and late surrender, which occurs after the dealer has checked and doesn't have blackjack. Surrender is typically used when a player believes their hand has little chance of winning, helping to minimize losses in tough situations.