Besides the following, to get a proper Fallout feel, I have used a mix of both regular Unisystem rules (AFMBE 2e revised), as well as Cinematic Unisystem (Angel/Buffy). I’ve also pulled stuff from “All Tommorow’s Zombies”.
Multiple Actions during combat rounds
Quick reference Experience costs
New/Different Skills list, based off an expanded Fallout set, with the skills truncated as in Cinematic Unisystem.
Tag Skills Are in addition to skill choices and add a natural area of expertise.
VATS Currently just Cinematic Unisystem “Drama Points” but will try and re-flavor it to feel more Fallout-ish in the future. For fair game play reasons, its not based on dexterity, like it would normally be in a proper Fallout game.
Perks are new qualities inspired by Fallout Perks.
see Armor for rules on armor encumbrance