In the Endless Isles, magic refers to the patterns by which the gods manipulate the physical laws of the universe in order to bend them to their will. The gods create these patterns and then can teach them to mortals, who use them without understanding them in much the same way that a chimpanzee would use a firearm. The power of magic is great, but it is not without limits. Skilled mages can create and project fire, control the weather, or warp the human body to harm or heal. They cannot create matter from nothing, instantly transport themselves or other objects from one physical location to another, or create life where there was previously none. Magic is also incapable of mind control or even more subtle mental influences. Magic in the Endless Isles is a cudgel, not a scalpel, and no weave has yet been created capable of manipulating the human mind without destroying it.
There are two types of casters in the Endless Isles. The followers of the old gods, among them shamen and hosts, maintain individual relationships with their gods, communicating regularly with them and often directly beseeching them for power when in need. These traditions go back for millenia. In only the past few hundred years, a new sort of caster has emerged. These magi learn the weaves of their spells by rote, and draw their power not directly from their gods but from the patterns those gods have woven into the fabric of reality. While they are less constrained by the sometimes-fickle whim of their masters, some scholars of the arcane have warned that these magi take a great risk by manipulating these cosmic forces without truly understanding them.