Weapons can be refined by combining a weapon with one of the same type. This increases the potency of the effect of the weapon by approximately 25%. The final refinement level is equal to the sum of the refinement level of the material and the refinement level of the base weapon. The level of the base weapon is the only one maintained. The base weapon determines the cost of refinements, so it is recommended to use lower refinement weapons as the base unless trying to preserve levels.