Denizens are beings of the Second Creation that do not quite belong in the Realm of Strife, and are sometimes referred to as outsiders or realm dwellers. It is believed that Denizens come from one of the many Realms of Origin, possessing little similarity of substance to one another, but all highly marked by the spiritual energies of their home realm. Typically summoned or lured away to the Realm of Strife, Denizens cannot permanently exist outside their home Realm unless they are somehow anchored to the Realm of Strife.
This is a complex area of study in and of itself, that has led to volumes of literature written on the nature of summoning Denizens. Most scholars are divided into two camps; one claiming that these beings are summoned from a parallel or overlapping Spirit world within the Realm of Strife while the other camp believes they are summoned directly from Realms all their own. This second theory has largely led to the development of the theories surrounding the Realms of Origin and the Creation in Three Parts.
The Codex of Creation separates Denizens into several Metaraces, each with common characteristics: