In a bend between the Spine and the Orient Sea lies the Valley of Fire.
The Valley is a desert plateau scoured by raging deflagration. Piles of rubble and ruins few and far between, huge billowing flames venting from the karsts, canyons and crevices crisscrossing the valley.
You have no reason to be there. Go home. Or come underground.
Under the desert, hidden from sight and the scorching sun, in these very canyons, karsts and crevices rivers flow and life abounds. Trees, ivy, honeysuckle, fungal sprawls and fauna teems nestled in the moist chthonic cavities, protected from the inhospitable inferno above us.
Over the millennia witch hunts, war, distrust and persecution drove to the Valley both monstrosities and practitioners of the occult arts. Here they found even weirder beings and more inexplicable phenomena.
To resist the vexing environment and wanton aggression covenants and congregations were formed. Eventually the Schools of Magic were founded; as they started accepting apprentices a greater influx of young, foolish and ambitious students came to the Hypogea. But conflict continued. Many schools were destroyed, together with their immense knowledge.
The Five Great Schools left joined in a Conspiracy, to find strength through numbers, to keep their friends close, and to keep their enemies even closer. Together they elect the Grand Sorcerer of the Valley of Fire, to lead them through the Dark.
Chthonic Codex is many things at once.
It's a book about the Valley of Fire by a yet undiscovered author. Fragments of this book are the primary corpus inspiring this project.
It's a campaigns setting, where magic academies meet weird tales in karsts under a fiery desert. New spells, new mechanics, new items, new monsters. The setting is completely autonomous and can be played without spells or monsters from other OSR games.
it's the name of a specific book, existing in the setting.
It's the name of the three volumes detailing the setting.