In blackjack, side bets are additional wagers that accompany the main bet, featuring unique payouts based on specific outcomes. The best side bets offer better odds and lower house edges, improving players' chances of winning, often involving specific card combinations. Conversely, the worst side bets come with higher house edges and rely on rare outcomes, increasing the risk of significant losses. While side bets can enhance the game's excitement and payout potential, players should weigh the associated odds and risks before participating.