system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] In ESB Vader is like "Luke let's team up and whoop the Emperor's ass," and then in RotJ he was just like "Nah I'm Palp's bitch." What caused the change of heart?
gpt
Proximity.

In ESB, Vader's off on the outer rim backwater mining outpost of who-the-fuck-cares, umpty-odd zillion parsecs from Coruscant. In RotJ, Palpy's never more than a few dozen miles away, in orbit. (On a Death Star. A Death Star full of loyal soldiery. And that's before you mention the fleet with active-if-less-powerful bombardment weapons, and a complete set of shield override codes...) It's one thing to offer to join up and go against the Emperor when he's on the other side of the galaxy, and you can easily claim when-and-if you go back that 'I was lying to the kid to get him to turn,' should the issue arise. It's another thing entirely to do it when he's (literally) sitting right there watching.