Why did Vader taunt Luke at the end of Return of the Jedi?

Question

I read an interesting thread here saying that in the confrontation between Vader and Luke at the end of Return of the Jedi, the Emperor is trying to goad Luke into attacking him (and therefore getting into a duel with Vader) in order to kill Vader and prove he is willing to turn to the dark side.

One question following on from this that I do have then; what was Vader's logic in taunting Luke (just before Luke goes crazy and chops his hand off)? Surely he wants Luke to join him, not kill him. He wants him to kill the Emperor so they can rule together as father and son, so why does Vader goad Luke into attacking him?

Answer 1

There are some factors at play here:

1. Vader isn't strong enough to openly defy the Emperor. Mind you, he's personally been through the situation where Palpatine sacrifices an apprentice to get an even stronger one (Anakin > Dooku), so it's not like he doesn't know what's at play. But he doesn't have the power or strength to simply tell Palpatine to go shove it, and Palpatine has a hold on him, so he must play along. But he also knows that simply converting Luke and making him strong is likely to result in some kind of "Kill him" déjà vu situation.

2. The seed for Father and Son to join forces has been set by Vader already. Vader wants to overthrow the Emperor, Luke knows that, and Luke knows that Vader isn't powerful enough by himself, and that Luke probably isn't powerful enough by himself either. As seen in Emperor Strikes Back:

Luke, you can destroy the Emperor. He has foreseen this. It is your destiny! Join me, and together, we can rule the galaxy as father and son! Come with me. It is the only way.

3. Luke must be converted to the Dark Side for any kind of team up to happen. Darth Vader cannot give up the Dark Side, so Luke must be tempted. That requires driving him to hate, and fear, and getting him to use that power.

The end result is a kind of hazy plan, basically along the lines of

• Seem to comply with the Emperor in converting Luke
• Actually convert Luke to the Dark Side
• Divert Luke's nascent power, and willingness to sacrifice himself to protect his family, against the Emperor
• Hope that the Emperor can be beaten in a 1v2 fight
• Take over as Luke's mentor/ally/whatever

Of course, it's a very narrow line between awakening Luke's power, and using it for Darth Vader's own purpose. Clearly, Luke took Vader off guard, and so Vader lost the fight in the end. I don't agree with the idea that Vader ever expected Palpatine to take on 2 Apprentices - at the very least, Vader's aware of one instance where Palpatine betrayed someone by using that very promise. He ultimately had to capitalise on that window between conversion and execution, because that was the only way to come through the situation alive and on top of the food chain.

Answer 2

Both Palpatine and Vader want to turn Luke to Dark Side, by forcing him to use his anger, hatred, blah blah :) Vader hopes that Luke, when sufficiently trained in Sith arts, would help him overthrow Emperor. In my opinion, Vader didn't want to lose against Luke, he just wanted to goad him to use his emotions and show him true strength of Dark Side. Of course, that didn't go to well because Luke almost killed Vader and barely managed to restrain himself.

Anyway, Vader didn't have much choice ("I must obey my Master"). Palpatine decided that Luke must be brought before him, and after that Vader could only hope that Emperor would make mistake and train two apprentices. That would break Rule of Two, and to paraphrase Darth Revan, any master training two apprentices is a fool. But, Palpatine was shown as having a penchant to break rules, and out-of-universe Rule of Two didn't exist when ROTJ was filmed.

Answer 3

I touched on this in a previous answer.

Vader wants to overthrow the Emperor, but believes that Luke isn't ready to kill him. Instead, he tries to provoke Luke into turning towards the Dark Side. In order to provoke him into fighting, he must taunt Luke, ubt must keep Luke focused on him, not the Emperor. Early in the fight, Vader underestimates Luke. Once he realizes that Luke is actually better than expected, that Luke might actually best him, he starts taking the fight more seriously.

Through the fight, he grows angrier and angrier, but still both trying to defeat his son and to turn him to the Dark Side.

From the 25th anniversary edition of RotJ novelization:

Vader was impressed with Luke’s speed. Pleased, even. It was a pity, almost, he couldn’t let the boy kill the Emperor yet. Luke wasn’t ready for that, emotionally. There was still a chance Luke would return to his friends if he destroyed the Emperor now. He needed more extensive tutelage, first— training by both Vader and Palpatine— before he’d be ready to assume his place at Vader’s right hand, ruling the galaxy.

So Vader had to shepherd the boy through periods like this, stop him from doing damage in the wrong places --- or in the right places prematurely.

[...]

For the first time, the thought entered Vader's consciousness that his son might best him. He was astounded by the strength --- not to mention the boy's timing, which was honed to a thought's breadth. This was an unexpected circumstance. Unexpected and unwelcome. Vader felt humiliation crawling in on the tail of his first reaction, which was surprise, and his second, which was fear. And then the edge of the humiliation curled up, to reveal bald anger. And now he wanted revenge.

[...]

His anger was layered, now --- he did not want to win if the boy was not battling to the fullest. But if winning meant he had to kill a boy who wouldn't fight... then he could do that too. Only he wanted Luke to be aware of those consequences. He wanted Luke to know this was no longer just a game. This was Darkness.

[...]

This accusation really made Vader angry. He could tolerate much from the insolent child, but this was insufferable. He must teach this boy a lesson he would never forget, or die learning. “Once again, you underestimate the power of the dark side …”