StingingVelvet: I think New Vegas did this best among 3D games, that I remember. Not the pure "tough enemies here, weak enemies there" of games like Gothic and MMOs, but not the "everything scales!" of Oblivion either. I guess Morrowind more or less nailed it as well, though you had to look more for trouble.
Basically have small patches of tough enemies spread around in logical places like a mountain top or cave, but walking the roads and plains can get you anywhere at any level.
Yup, area scaling of loot and monsters is the way to go. It encourages exploration to find places with better loot which is guarded by hairier monsters, and it also feels more realistic and immersive that roads and cities are safer than caves, ruins and wilderness.
And in open games like the TES games and Might&Magic games area scaling means that if you get ass kicked in your current area, you could always find an easier area to explore.
StingingVelvet: Basically have small patches of tough enemies spread around in logical places like a mountain top or cave, but walking the roads and plains can get you anywhere at any level.
Fenixp: Yeah, that's an approach I like as well, and it's what Bethseda usually tries to do - applies even to Oblivion, to an extent (roads are safer than the wildeness.)
Only because roads are patroled by friendly (unless you're a criminal) guards and soldiers, I think. The best thing about Oblivion compared to Morrowind was the much more dynamic and emergent gameworld, where you could stumble upon the corpses of monsters killed by soldiers, or even stumble upon the fight.