Gaffer Tape said:
Ugh, another irritating retcon. It seemed so much cooler when it was always told that years of misuse of the dark side had deformed his face. And, in another fun example of Lucas making this up on the fly, he was actually going with this story in AOTC, as Palpatine looks much more ragged than he did in ROTS, after Lucas changed his mind.

Is it really a retcon? Where was it official that:

A: The 'Mask Theory' is legit.

B: That years of using the darkside had made Palpatine ugly.

I'd always though he was just really, really old in the OT. I don't know if different explanations for ambiguities count as retcons.