Every weapon, from a simple stone club to a general's war sword, can have at least one part that's not as good as the others. With this skill, an experienced weaponsmith can swap out a worse part with a better one, improving the weapon's overall quality. Skill and components needed vary by target's starting quality:
Exceptional+ needs 51% skill, one strip of primal material and 5 enchanted parts. Good+ needs 26% skill, 5kg divine material and 5 exceptional-quality parts. Standard- needs 5kg exceptional material and 5 good-quality parts. The 'parts' are grips for shields, and weapon parts for everything else.

Each weapon can be upgraded up to three times -- worse weapons can be upgraded more than better ones. Each upgrade 'tier' goes up to a maximum 5 out of 5, and must be completed before the next one can start. The effect the merchant can give is based on this skill chance, repair weapon skill chance, int score, and their mastery of the material of the weapon. Syntax: use upgrade weapon at <weapon> The weapon, the components, and all required tools must be in the merchant's inventory.