In the Star Wars universe, where does Darth Vader stand in the empire pecking order? Do Mas Amedda and pre-demoted Sly Moore outrank him?
Darth Vader was, for all intents and purposes, the herald of Emperor Palpatine. He did the Emperor’s will, and his orders were treated as though they came directly from The Emperor.
Strictly speaking, this would place Darth Vader second on the Imperial pecking order, under Emperor Palpatine himself.
Unless the Emperor says otherwise.
A few individuals were given special dispensation to give orders to Vader. The Emperor forbade Vader from killing them, usually as a punishment.
One man who was simply too important to risk Vader’s wrath:
The Emperor considered Grand Moff Tarkin and his Doctrine of Fear as absolutely vital to his plans, and made it clear to Vader that he was untouchable.
Good thing for Admiral Motti, who would have died if Tarkin had not ordered Vader to release him.
While supplemental sources indicate Tarkin didn’t like Vader, his interactions in A New Hope suggest that Tarkin respects Vader, and knows he was once Anakin Skywalker.