The mysterious arcane knowledge that these persons wield is often frightening. At the outset, these people may not seem to present a challenge for a good sword or a stout club, but as their studies grow, they have been found to be formidable opponents. They can be limited by their power level, but more than one mage has been known to inflict great fear in others and when they were seemingly defeated, disappear. Not dead of course, but preparing to return and finish the job they started.
The prime requisite of Mages is intelligence, allowing them to learn powerful spells.