Gloomseeker: @dtgreene: Fallout 3 had the same mechanics Oblivion used when it came to taking damage meaning that power armours didn't stop low calibre bullets like they were supposed to.
That's not what I was referring to. I was referring to how the game decides whether an attack hits in the first place.
Morrowind and Fallout 3, while they look like first person action games, do not actually play like such. When you attack an enemy, the game rolls dice in the background; if you get a good roll, your attack hits, otherwise it misses. This is why, in Morrowind, if you have low skill in a weapon type and keep swinging at a mudcrab, your attacks will (mostly) keep missing, even though the mudcrab is right there. (To put it another way, it's more like the way Fallout 1 and 2 determine whether an attack hits.)
Oblivion (and, to my understanding, Fallout New Vegas) are different. When you attack, if your weapon collides with an enemy and the enemy doesn't happen to be blocking at the moment, the attack is guaranteed to hit, just as you would expect in an action game; the only effect of skill here is to determine the amount of damage you do on a successful hit. (I note that the block mechanic is what you would expect in an action game; you hold a button (or key) to block, and if you're attacking or casting a spell, your block is cancelled during that time.)
Incidentally, under what I consider a reasonable (possible) definition of RPG, Morrowind and Fallout 3 would qualify, but Oblivion and Fallout: New Vegas would not, just because of this mechanic difference.