Fortification is performed at the Blacksmith at the south of the fountain. Proceed with caution, as a failed fortification can result in a broken item. Armor and weapons can be fortified, but accessories cannot.

Fortification stones are needed for this process, which you can get at the Laboratory via extraction. Catalysts increase the chance of a successful fortification.

You can restore broken items with the Magic Stone of Restoration, an item which can be purchased in the Cash Shop. The broken item will then be restored without Fortification bonuses, but item will retain the same grade.