The descending stair

The "descending stair" is a cosmology model proposed in Classic Play: The Book of the Planes. It is based on historical cosmogonies including Kabbalah, Gnosticism, Alchemy, and Plato's Cave.

As the book explains:

"The Descending Stair cosmology traces the descent of energy through the cosmos (Games Masters with a religious bent could do well to research the tree of the Sephiroth). The highest plane is the Firmament, which then descends through the Questing Grounds (an engine for converting the pure energy of the divine into forms compatible with the lower cosmological regions) and the Afterworld. The next plane in the chain is the Vault of Stars, which traces the shapes of the energy’s intentions and destiny. The Astral and Dream planes form a bridge between the wholly immaterial upper planes and the more physical lower planes. The energy explodes into the lower regions in the form of the Positive Energy Plane, which then splits into the four Elemental Planes. These planes provide the raw ingredients to form the Material Plane. The Shadow Plane and evil planes are aborted regions beyond the stair."

The Descending Stair

I mentioned this cosmology years ago during earlier forays into plane building, but I lost focus and forgot about it for a while. I recently regained interest after reading the two-part article "Touched by the Otherworld." To that end, I would like to retread and revise my ideas for this cosmology.

The cosmology may be imagined initially as a series of supra-planes or "worlds", each of which gives rise to the next: Briah, Yetzirah, Assiah, and Gehenna. These worlds aren't just alien locations created by game convention, but energy channels that actively and constantly feed into sustaining their derivatives.

• Briah is the world of creation. It encompasses the upper planes, planes of order, and planes of discord. It is the abode of the aberrations, celestials, and similar. These planes give rise to souls, which descend into the following planes to make life. Sometimes, existing spirits may enter incarnation.
• Yetzirah is the world of formation. It encompasses the elemental and transitive planes. It is the abode of elementals, giants, and similar. This would include the Ethereal Sea from Beyond Countless Doorways by Malhavoc Press. The elemental planes interpenetrate the prime plane, giving rise to the weather and other natural phenomena.
• Assiah is the world of action. It encompasses the material plane and its echoes. It is the abode of beasts, humanoids, fey*, and similar. This would include the preternatural planes from The Faerie Ring books by Zombie Sky Press.
• Gehenna is an aborted world. It encompasses the lower planes. It is the abode of fiends, undead, and similar. These spirits are born from the wills and souls of the preceding planes.

*Fey in particular occupy something of a unique niche, inspired by The Complete Guide to Fey and Exalted: The Fair Folk. I said this before in ancient posts, but fey are reincarnated beings: spirits embodied in physical fleshy forms. Ancient aberrations became trapped in the material plane as it formed, becoming the nature spirits of the prime plane and the alien visitors of fairyland, and this process continues on other spirits including fiends and undead.

One of the reasons I like this model is that it provides a better context for the messy planar cosmology and monster taxonomy of D&D, which otherwise feels pretty arbitrary. I will incorporate it into my Indo-European cosmology as another way of looking at the creation and ordering of the universe.