High Magic, sometimes referred to as Old Magic, is wild. Controlled by no wizard or mage, High Magic is best understood by dragons, and by association, griffs (though the knowledge of griffs concerning High Magic is confined to scattered bits of Old Speech that are half hearsay and lore). High Magic is neither fundamentally good nor evil. Older than the Implementors themselves, High Magic is the wild stuff that the Empire was formed of—the uncontrollable, dangerous energy of Creation and Destruction, the Conjuration of the unknown from the known. High Magic also invokes Plant Growth & Communication Spells.

With powers that are seemingly unlimited, arcane combatants are able to create either illusions or physical effects, ranging from flinging fireballs at their foes to making themselves appear so horrendously ugly that their enemies instantly fainted.

Old Speech, the runic language of dragons and some druids, details the power of High Magic, and lists the Names (true names, not call names) of every creature, animal, plant or other property in the Empire. All Spells are first composed in Old Speech, and some can only be deciphered through Old Speech today.

High Magic is not traditionally associated with the Underground, as it takes its power from the unformed vastness of the Overland Sky. High Magic is dangerous, most of all to those who attempt to use it without fully understanding what they are doing, which is everyone who has ever attempted to use High Magic. Some Mithican creationist legends even go so far as to contend that the founding of the Great Underground Empire itself is the result of one colossal malpractice of High Magic use.