[shadow55]

or it could just be once you get a wep skill to 10 you can dual wield..

or maybe once you get any skill to 10 a special ability/benefit is unlocked..

e.g. armor handling lvl 10 = armors weight reduced by like 40%~
long blade lvl 10 = +5 dex (faster with the sword)
pistols lvl 10 = dual wield
electronics lvl 10 = EMP pulse to discharge someones belt..

etc...