Lucky bucks are coupons given as promotions by casinos that pay bonuses on winning even-money table-game wagers. For example, a 3-2 lucky buck played with a $2 bet in blackjack pays $3 on winners rather than the standard $2. The most common lucky bucks are 3-2s, 7-5s, and 2-1s. Gamblers almost always have a significant advantage when playing them, which is why casinos tend to limit their use to low-stakes bets.