User blog comment:Staw-p/Luffy should have a weapon./@comment-3279487-20111228140337

A weapon would be an handicap for Luffy since he is an idiot and has no skill at all (remember the fight with Arlong?). For hand-to-hand fighters there are some types of protections worn on arms and legs which are able to stop blades, but he won't use any type of weapons or protections simply because it doesn't fit his character.