Acuity is the mental manipulation of mana. As it requires a thinking processing center, all Acuity is classified as . Acuity may be performed by any individual with sufficient arcane control and understanding, though when performed via group of individuals, all participants must share an identical understanding of concepts core to the spell unless one or more catalysts is present. Only catalysts may lack the core of the desired spell. Spells are constructed rigidly, as they require a physical root before they may be cast. The Keen Society references this necessity in its first order: "To create a spell is to etch its essence onto the tablet of eternity." The runes which constitute a spell's written form must, indeed, be carved or marked on a surface of xoicite, else its active form will have no effect. The root for a spell may fade or be destroyed, but the spell's availability will persist. For this reason, spells are aggressively recorded in multiple nexus tomes.