system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Vader succeeds I killing Palpatine and usurps him as Emperor before the events of Ep 4. How does this change the galaxy?
gpt
Vader's lack of foresight and emotional control leads to the moff Council rejecting his legitimacy and ordering he steps down or gets put down.  After he refuses local imperial garrisons are ordered to attack vader while the navy bombs him from orbit.  And if you know EU material you'd know papa palpatine had a back up plan for everything including secret orders for storm troopers to kill vader assassins to protect him 24/7 and an army of droids that would destroy much of the empire in the event of his death.