See Challenge Rules
Weapon and armor proficiency comes from combat training. Any character can pursue combat training at any time. When one trains, they choose the weapons to train with. As characters grow more proficient with a weapon, they become more deadly.
There are four types of weapons: missile, melee, mixed, and non-lethal. Melee weapons are traditional hand to hand weapons. Missile weapons are self explanatory. Mixed weapons include daggers and hand axes that mix the properties of melee and missile weapons. Non-lethal weapons are designed to entangle, disarm, or frighten opponents.