For every being the book tells what it looks like, where it lives, how it behaves, what it can do, how it lives and dies, what it does for and to the peoples, and what they believe about it. That is enough to put it in a story without contradicting the world: to know that a basin farmer without a share in a plough-team is poor, that a Dark Elf house holds its fungus caverns by chamber-right like water, that iron would not ward off the Rust-Hosts, or what a Veil-Walker takes as its fare.

It also gives what the peoples make of their beasts and plants and monsters: the omens, the charms, the festivals, the proverbs, and the mistakes. So are the hunts: the bounty on a wolf pelt, the pass bear the whole road turns out for, the herb fetched from a plane that kills. Those are often where a story starts.

Where the setting names only a kind, the book holds the kind: sheep, barley, lichen, the hawks a lord flies. Breeds, varieties, and the names of particular animals are left to whoever needs them. Where the setting does not know something, the book does not pretend to: whether the deep-witnesses of the open sea are a people, a beast, or something the sea alone could make is not settled, and the entry says so.

The book carries no game rules. A being’s abilities are facts of the world, what it can do and what that costs, never numbers, and anyone who builds a game on Caeldon makes those for themselves.