Quote Originally Posted by Tergon View Post
Mages Guild, yes. Thieves' Guild? Nope. If you didn't steal stuff and fence it, you couldn't get the quests unlocked. If you failed to sneak past NPCs and monsters during the quests, you got swarmed with guards and undead. You could not become the Grey Fox until you actually proved you were a competent thief, unless you were so game-breakingly powerful that you could casually fight off the full force of the Imperial City Guards. At which point, well, it hardly mattered anyway, did it?

Morrowind did it better than Oblivion, especially with the Mages' Guild, but Oblivion's Thieves' Guild was far better than Skyrim's.
I should note that, however, playing anything other than a mage was intentionally nerfing yourself. Oblivion Wizards are a bit like the DnD kind.