Is there an in-depth explanation of the s.p.e.c.i.a.l. system anywhere? I'm trying to convert it to a tabletop system, so it would be helpful to know exactly how it works. Thanks for any help!

It works as your major skills and governs all the other skills. When you level up there is a large skill list, the s.p.e.c.i.a.l skills govern how many points you have in each skill at the start. Also things like strength and perception also help with other things. Strangth - how much you can carry, Perceptions - Vats, compass

Thanks! Any suggestions for how to get ability modifiers for skill checks? Or how combat skills like 'Small Weapons' would affect combat with those weapons? I like trying to keep most of it with d20, but I might be able to use some others.

Google Fallout pen'n'paper... There is complete pen and paper version of S.P.E.C.I.A.L system available for free on the internet, made by guy named Jason Mical. Link to zip that should have it as .doc is http://www.jasonmical.com/files/fopnp.zip.

S.P.E.C.I.A.L isn't very good as pen and paper RPG, most of damages are bit unpractical as dice rolls. I'd take somewhat modified GURPS or Millenniums End or Living Steel if I would run Fallout as real RPG, even modified d20 (loathe that system), above it.

Thanks guys! I'll look at those. I hadn't seen the one on the Vault. I'll look at the PnP one too.

EDIT: Anyone know where the character sheets are?

In the PnP thing that was linked, it said the the Character Sheets were in another document. Character sheets are what you use to keep track of stats and stuff. Doesn't really matter, though. I'm gonna homebrew my own system, I've decided. Thanks, though.

http://falloutpnp.wikia.com/wiki/Main_Page has all the info on the officially unoffical Fallout PnP game.