This isn't exactly correct. Oblivion's overworld and most dungeons were hand-built. The only procedurally-generated parts were unnamed caves/dungeons.

It's been forever since I read about this but the map itself was generated randomly. It was then manicured by hand. The buildings and cities and dungeons were all hand made, yes. But the dungeons were all using such similar art assets and there was a real lack of variety, so they all rather felt the same. Not that I'm complaining, it was an amazing game and probably one of my favorite gaming experiences of my life. It was way ahead of its time.

It's weird to think of Oblivion as in any way procedurally generated, coming as the sequel to Arena and Daggerfall that really felt like RPG versions of Elite.

Are you sure this is correct? I Feel like both were hand built overworlds, but Oblivion just had less decoration because of hardware limitations at the time.

I think I’ve misremembered this rather badly. It was used for things like tree placement, but not gross physical features like mountains.

I’m sure I read something at the time that said what I’m describing though.