Codex of Abyssal Layers

Though the Abyss is commonly believed to have 666 layers, many sages believe the true number to be infinite; of course, as there is no rhyme and reason to their interconnections, keeping track of these layers and determining a solid count at first seems as though it may be impossible. Fighting this belief is a millennium-old project founded by Factol Clarille herself, founder of the Fraternity of Order, in the fourth year of the formation of her faction. After the discovery of the once-lost keep of Cabiri, an obyrith with scrying portals reaching throughout the Abyss, by agents of the Fraternity of Order exploring Pazunia, they realized the need to categorize the many-varied and supposedly infinite layers of that plane. Thus, Factol Clarille instituted a project that would enumerate and describe every layer of the Abyss as it was reported to them, a project that would result in a single definitive listing. This listing, known today as the Lexicon of the Abyss, has now become the standard reference for Abyssal layers even upon the Material Plane, the central source for both name and number, number assigned according to order of confirmation. Names for layers are based on names used by any locals or, if such names are unknown or cannot be spoken in Common, by those issuing the report to the Fraternity. By convention, while a layer may be informally listed based only on basic reports, it is only to be assigned a number when the faction has confirmed those reports and verified that the traveler has not simply arrived in a previously-unknown location within an already-recorded layer, to prevent confusion and unnecessary duplication. Past errors have led their standards to become increasingly tightened over the years, and as a result, many are surprised to see the high layer number given to commonly-known layers; the Guvners prefer to be certain. Presently, 679 distinct layers have been officially recorded, with 141 known to be both survivable and habitable in the long term by planars. Here then is a portion of the Lexicon of the Abyss.