Yes, a casino can refuse to pay out winnings under certain circumstances. Common reasons include violations of the casino's rules, such as cheating or collusion, failure to provide valid identification, or if the game was found to be malfunctioning. Additionally, if a player is suspected of engaging in illegal activities, the casino may withhold payouts pending further investigation. It's essential for players to understand the specific terms and conditions of the casino to avoid potential disputes over payouts.