Marked cards

Marked cards are playing cards that have been altered or subtly modified in a way that allows someone to recognize their identity without obvious signs. This is often done through small changes like patterns, symbols, or variations in the back design that are invisible to most players but can be identified by someone who knows what to look for. Marked cards are used in cheating scenarios to gain an unfair advantage, such as knowing opponents’ hands or predicting future cards, which violates fair play principles in gambling and card games.