Order 66 comes from Star Wars: Episode III – Revenge of the Sith, where the order commands clone troopers to turn on the Jedi they served alongside. The tie-in video game retells the film's story, giving players that same pivotal moment in playable form. As Star Wars memes grew online, the phrase became shorthand for any sudden betrayal, especially when a trusted ally flips without warning. Its short, ominous delivery makes it easy to drop into edits, and because almost every Star Wars fan recognises the reference instantly, it still works years later as a compact dramatic twist.