“保险”(insurance)是指当庄家的牌面为A时,赌客下的一种赌注。照一本《Casino Gaming Dictionary》(娱乐场赌博辞典)的辞解释是:in black jack ,a wager that dealer has a ten card face down when an ace is showing and which pays two to one。臺湾赌神戴子郎的解释是:“当庄家面牌为A时,会问赌客是否要保险。保险为赌客另下注(一般以原注额之一半为上限),赌庄家底牌为十点牌,即庄家拿Black jack。庄家若确为Black jack 则赌客获赔保险额之二倍。若不是Black jack,赌客损失其保险费。”