>>39102646>sleight of hand>outright ignoring rules/doing things your opponent doesn't catch>force shuffling>adding/removing random cards at random times throughout an event>gamesmanship on any number of levelsIt was rampant a few years ago. Some well-known kid, Michael something, held a Greninja Break card in his lap, and tried to clench it in his ass cheeks when he was asked to stand up.
If you think you can't cheat, or that no one does cheat without getting caught, you're delusional.
Card games are the easiest thing to cheat in because the onus is on the opponent to stop you, and unless you do it blatantly a POP judge will just slap you on the wrist with a warning anyway.
Judges have gotten better since streaming has gotten more popular, but consider how many hundreds of tables don't get a dedicated babysitting judge, or video camera watching them.