"Hrothbert of Bainbridge. Bob is fine." He shrugged. "Magic comes from energies, directed by will. That can involve concentration, runes, ritual, potions, any number of things. There are also people and beings that are inherently more magical than others. I myself was a sorcerer and necromancer of some note before I died. Since then I have acquired quite a bit more knowledge, though much of it is necessarily theoretical without a body."