i have been thinking of an awesome idea of a DnD based fallout Role Playing Games (That means old fashoned books and paper an pencils and... uh oh... SIMPLE MATH!) i like fallout 3 and NV but you are soo limited on what you can and cant do. while in DnD if you wanna do something that is possible by you, then you can do it. of course you would still have to have a DM type guy (i would call him the Overseer instead of the Dungeon Master), weapon degredation, skills and SPECIAL still are there but you have the freedom of doing WHATEVER you want. and 'ell for that much you can even make your own maps up of the area you live in. or an area that intrests you by printing up a Google earth map.
also weapon mods are pretty much infinite, weapon selection is infinite, and weapon ammo type is almost there too. what ever is in the real world today can be used in the game, BUT you can just use everyweapon cuz the weapon list would get cluttered real fast. EOtech sights, 100 round AR hicap mags, stability Foregrips for AR, anything your imagination can think of.
A videogame can go only so far, but your imagination is limitless.
The SPECIAL system is quite easy to implement with a little work..
If you have a regular gaming group get together and bish bosh it in a slap dash fashion, it may suprise you how flexible it is.
If you can, and have not already get your hands on 1, 2 and tactics.
As these are closer to P&P rpg's in style, look at how range and to hit chance works and is effected by perception, gun, skill and lighting.
See how different criticals effect different creatures and sixes.
Take some tables from FOW then mash it all together, either it'll work or you'll come away with something minor you like for your regular game sessions.