In the prequels we see that both C3PO and R2D2 are Anakin's droids and they clearly both know that he's gone over to the dark side.
I would like to know an in-universe answer for the question; Why did they not tell Luke?
that Vader is Anakin?
In the prequels we see that both C3PO and R2D2 are Anakin's droids and they clearly both know that he's gone over to the dark side.
I would like to know an in-universe answer for the question; Why did they not tell Luke?
that Vader is Anakin?
From Wookieepedia:
Organa entrusted R2-D2 and C-3PO to Raymus Antilles, the Captain of the Tantive IV, who was instructed to treat them well and to wipe C-3PO's memory. Although R2-D2's inability to speak basic spared him from experiencing a memory wipe, it did undergo reprogramming to restrict access to the holo-recordings of Leia's birthparents, including Skywalker choking Amidala and her deathbed during delivery, to ensure that Leia's true parentage remained a secret.
I think for C-3PO the situation is clear: After his memory wipe he shouldn't have been able to remember that Vader was Anakin. For R2-D2 it is very likely that the reprogramming prevented him from telling Luke about Skywalker being Vader.
R2-D2 and C3P-O had their memories wiped by Captain Antilles shortly after the birth of both Luke and Leia. If not R2-D2, then at least C3P-O did.
From a scene in Revenge of the Sith:
Senator Bail Organa: Captain Antilles?
Captain Antilles: Yes, your Highness?
Senator Bail Organa: I'm delivering these two droids into your care. Treat them well, clean them up and get the protocol droid's mind wiped.
C3P-O: What?!?!
R2-D2: [Beeps] ... [Chuckling beeps] (I assume R2-D2 says somwthing like "Me too?! We aren't going to remember anything?!")
C3P-O: Ohhh nooo!
Although R2-D2's inability to speak basic spared him from experiencing a memory wipe, it did undergo reprogramming to restrict access to the holo-recordings of Leia's birthparents, including Skywalker choking Amidala and her deathbed during delivery, to ensure that Leia's true parentage remained a secret.Maybe this also prevented him from telling Luke about Skywalker being Vader. – Philipp Mar 02 '14 at 01:12