Magic Strength, abbreviated as ATS, is a recurring stat. It is paramount for arts damage dealing, and most important to those who do deal arts damage in combat. Magic Strength is compared against the opponent's Magic Defense to determine the amount of damage dealt. Magic Strength is only provided by quartz though sometimes can be boosted in battle by arts or items and certain equipment comes with a positive or negative bonus to the stat. In FC, Estelle's Morale and Kloe's Kaempfer crafts respectively raise and lower magic strength as well. This was corrected from the second game on.