Mage spells are arcane effects created by a sentient caster in hopes of attaining a certain (usually predictable) outcome, such as a bolt of fire. Most mage spells tend to focus on either augmentation of existing matter, harnessing elements or otherwise applying new elements and abilities to desired objects or persons. This rather offensive and utility-centric nature makes the mage spells almost a polar opposite to the Priest spells, which are almost without exception based on restoration.
The arcane spells require intricate movement of the body, arms and hands. This means that all but natural mages with inborn abilities to wield the arcane energies are required to wear little to no armor to keep themselves from being encumbered, and to keep the bulky armor from interfering with the spellcasting.