The payout structure for blackjack side bets varies based on the specific bet and casino rules. Side bets, such as "Perfect Pairs" and "21+3," allow players to wager alongside their main bet, often offering higher payouts due to increased risk. For instance, "Perfect Pairs" may pay 30 to 1 for a suited pair, while "21+3" could offer 5 to 1 or more for a strong poker hand combination.