Mages are the weavers of arcane magic in Ehrdi, and only they can control its energy to their own use. How they do so varies from the mage subclasses, but the general mage memorizes time-tested spells and can recite them offhand -- those they can't are kept in spellbooks and recited word for word. More gifted mages can write and create new spells.
Anyone with a knowledge of Arcane can use and activate runes or magical items, but mages are the only ones who can innately cast magic without an outside aid. They must still know and speak in Archaic to cast spells, but they do not require the aid of items or runes to do so. The number of people with the natural ability for magic is low; aside from Dragons (who are all magically gifted) only roughly 8% of the world's population can cast magic on their own. In some cultures, this ability is near non-existent, such as the Senjo. In others, it is common enough to warrant a significant impact on their culture, such as the Drude.
Necromancers act in the same manner as normal mages do, except they focus on the dead, or rather, undead; whether it be using magic to create hordes of zombie and skeleton soldiers for their own ambitions or simply studying the effects of decay and the body's absence of a soul, necromancers use their magical prowess in the realm of death. The practice of necromancy is banned in almost every country, but it is still practice underground by numbers large enough to consider them a true class; however, the number of necromancers with dreams of conquest are fairly rare; most seek to understand death, not to conquer with it. Some necromancers have been known to make themselves a sort of sentient undead to prolong their life and work on Ehrdi.
Often confused with necromancers, Infernals are mages that have sold their souls to demons in return for magical abilities. Usually the powers granted come with a price (other than their soul), often in the form of some mutilation or another, such as the removal of an eye, or permanently breaking the fingers in the left hand. Infernals are often granted near-immortality as well, though many of them meet death regardless, in one form or another. Though a few are known to be loners, most infernals are rarely found outside of demonic cults and often serve as the head priest or a council member.
Scholars are mages that focus all of their magical ability through books, scrolls, and research. They are somewhat like bards in that they have an immense knowledge of history and lore. Unlike bards, however, they are often more stingy in sharing their hard-earned knowledge. More common in civilized countries and all but nonexistent in others, scholars spend their days locked away inside, their nose deep inside a book.
Elementists focus on magic pertaining to the main elements: fire, wind, water, earth, electricity, and metal. Sometimes confused with druids because they can control some factors of nature, elementists get their powers from within, not from a nature deity. Though rarely incapable of using magic of other areas, elementists choose to concentrate on the elements; some even stick to one main element, and are often referred to as a "fire mage" or whatever element they specialize in.
While gifted with magic like any other mage, rune inscribers often can only preform magic through runes -- many mages practice the art of rune inscribing, but few specialize in it out of choice. Found predominantly in Duendo tribes, rune inscribers paint, engrave, carve, and write runic symbols to invoke spells that are often activated: upon the completion of the rune, a command word is spoken, or a certain action is taken. Rune inscribers often multiclass as other professions in tow with their rune-writing abilities.