I'd like some clarification on skill allocation in Advanced Campaigns. More specifically, can heroes obtain skills that fall outside of the printed skills on their character sheet?

The RtL manual says the following:

Each hero player draws the skill cards indicated on his hero sheet, plus one extra skill from the skill deck of his choice. Heroes begin the campaign with only one skill, however, so each hero player then chooses one of these skill cards to keep and discards the others back to their appropriate decks. The traits shown on the hero sheets are unchanged in the Advanced Campaign.

Does this mean a hero can, for instance, choose a Subterfuge skill card even though he has no printed Subterfuge skill on his character sheet?

Yes, you can learn skills outside of your starting set. There's a rule preventing acquiring feats outside of your starting set. Our group confused the two for a while.

Aye I know about that one, I guess we always just (wrongfully) assumed it was the same for skills, I have to admit I was a bit surprised that I couldn't find that rule mentioned anywhere.

We played 2 full campaigns before we realized that you could buy any skill you wanted. Kinda weird though but it does allow more customization and more flexibilty in the characters.

Drglord said:

Kerrigan isn't talking about buying skills, though, he's talking about drawing the fourth skill card during "character creation" (for lack of a simpler term.)

In vanilla, IIRC, the rule was draw cards as printed and then trade one skill for another from the same deck, if desired. That effectively meant the last "bonus" card would always come from one of the categories that your hero has a non-zero value for. But in RtL (and this is news to me, too, btw) it looks like the "bonus" card can be drawn from any given deck, even if the hero has 0 in that category. He gets his skills as printed, plus one from the deck of his choosing. Then he has to choose one of these to keep and discard the rest.