You can either upgrade items - up to additional 20 levels more than the item currently has (level is marked with an asterisk), as well as you can destroy them. To improve the item you must have developed crafting skill: Metallurgy - this will give you an additional 10 levels of improvement.
Depending on the type of item you can upgrade by further 10 levels: Armor Reinforcement (armors), Weapon Forging (weapons), Shield Casting (shields), Archery Craftsmanship (bows).
To upgrade the items you must have the appropriate materials - the best and easiest way to get them is by destroying unused stuff.
Below is a list of all materials that are used in the game:
- Elements of chainmail
Fusion - if you have developed this skill, you can insert (as well as draw) the magic stones, adding, for example, extra damage from one of the elements, increasing the resistance or raising stats. The more developed the skill is, the better stones you can insert or join together (the same five stones of the same level gives one stone at higher level).