GameShark and Action Replay codes: For many, real "cheat codes" meant plugging in a cheating device. These devices could give infinite life points, unlock cards, or alter opponent behavior. Alex remembered booting up a code that spawned an impossibly strong boss monster on their side; the duel lost its challenge but let them breeze through to the story’s later cutscenes.
If you grew up with a PlayStation 1, you know that is notoriously one of the most difficult card games ever made. Unlike the modern TCG, this game follows its own "Trial by Fire" rules where the AI seemingly cheats, and powerful cards like Blue-Eyes White Dragon or Meteor B. Dragon are nearly impossible to obtain through normal gameplay.