Prop bets (proposition bets) in poker are side bets on specific outcomes including performance challenges (winning X buy-ins in Y hours), physical goals, or predictions about specific table events. They are common in high-stakes environments as a way to add action and can involve significant amounts. Poorly structured prop bets can create conflicts of interest, especially when a player has a prop bet that incentivizes behavior that harms other players at the table. Professionally, prop bets should be carefully evaluated for actual EV, not just the exciting nature of the challenge.