If a knowledgeable Wizard is what makes a mage, what makes an archmage? The title, not the class. The title can be bestowed formally for any number of reasons (e.g. courtier rank, employment) but among wizards, an "archmage" is someone who has so mastered (at least a school of) magic that they can devise new spells/variant spells with ease because they UNDERSTAND.#Realmslore

— Ed Greenwood (@TheEdVerse) June 1, 2019

Huh. I always thought an archmage was an elite user of the Art, though devising new spells would fall under being so, anyway. Indeed. That's the line, though: except for individuals given a court or rank title of "Archmage" (who may not even wield the Art, though such instances are rare), "archmage" means not just an elite mage, but one who understands magic well enough to easily alter or create spells.

— Ed Greenwood (@TheEdVerse) June 2, 2019