Planes¶
"Working towards a more unified and simpler Cosmology." — the opening line of the Cosmology Revision (S001)
Terrun is not one world but a stack of them. The planes are the layers that sit beneath, beside and beyond the Material Plane, and almost everything in Terrun's cosmology (where souls go, where demons are kept, where magic comes from) is a statement about which plane touches which. The scheme below follows the newest cosmology; the older classifications that the archive used for a decade are kept under Earlier accounts, because many other pages still speak in their terms.
The current scheme¶
The Cosmology Revision divides the planes into two kinds.
Inner planes, also called inner layers, subplanes or dimensions, are "often also thought of as 'alternate' but parallel planes. They act as different 'dimensions' of the Material." They overlap the Material and intersect it in space: a portal opened at a place crosses to a consistent place on the target plane. Adjacency, however, need not hold. "Open a portal to the Shadow, step through, walk 100 yards and open a portal back may put you at a location many miles away."
Outer planes "sit distinct from the material. There is no correlation in space or position. Travel to and from them is often random, chaotic, difficult and dangerous. They have few entrances, which are often tightly controlled."
| Plane | Kind | One line |
|---|---|---|
| Elemental Planes | Inner | The raw elements, older than every other plane; home of the elementals. |
| Fae Realms | Inner | The Titans' dominion between the elements and the Material, now blighted. |
| Material Plane | Inner | The Mortal Realm, where matter is manifested by the elements. |
| Shadow Realm | Inner | Shadow, memory and thought; the only known road to the Astral Shards. |
| The Rift | Inner | A Fifth Age wound: the decaying Mithis shard merged with the Shadow. |
| Mithis Plane | Barrier | The shard moved to wall the Abyss off from the Material; now decayed. |
| The Abyss | Outer | The Seven Hells, prison planes made from Astral Shards. |
| Netherworld | Outer | The Sea of Souls, where the dead materialize. |
| Astral Plane | Outer | The carved-apart shards of the gods, reached only by their own entryways. |
| The Void | Outer | The space between worlds, where no layer of Terrun reaches. |
| Energy Planes | Inner (older scheme) | Positive and Negative, the fuel of life and divinity; absent from the newest revision. |
The group names used on this page (inner, outer, transitory, transitive, material planes) are classification labels, not planes in their own right.
The two layering chains¶
The Revision gives the Material Plane two stacks of neighbours, one elemental and one astral. Written as the source writes them:
- Elemental layers: Elemental ⟷ Fae Realm ⟷ Material
- Astral layers: Astral ⟷ Rift / Netherworld / Abyss ⟷ Shadow Realm ⟷ Material
Read from the Material outward, the elemental chain runs through the Fae Realms down to the Elemental Planes, while the astral chain runs through the Shadow Realm to the three middle planes (the Rift, the Netherworld and the Abyss) and on to the Astral. The Shadow Realm is therefore the hinge of the astral side: "Astral domains are primarily connected through the Shadow Realm along the Asomatus Lines which empower them."
This structure belongs to Terrun alone. The Revision is explicit that "the subplane structure outlined above is specifically relevant to Terrun"; another world's layers may differ, and the layers of one world do not extend into the Void between worlds.
Who may visit where¶
The cosmology documents record, plane by plane, which kinds of being can be present. Three forms recur: a material form (a body), a projection (a spirit visiting a non-native plane, "partially substantial" and easily destroyed), and an astral form. The table merges the Revision's notes with the older cosmology's where the Revision is silent.
| Plane | Forms that may visit | Magic there |
|---|---|---|
| Elemental | Material forms with powerful elemental protection; energy-based projections (S001). | Elementals' own; the harsh conditions and lack of food defeat most other life. |
| Fae Realms | Material forms, "in most cases", though the landscape is volatile and its natives wield considerable elemental power (S001). | Not stated. |
| Shadow Realm | Material or astral forms (S001, S013). | "Magic does not function here", but strong minds can alter the plane and powerful beings can bend it wholly (S001). The older cosmology excepted Astral magic (S421). |
| Netherworld / Sea of Souls | Projections only; no gateway can open, "due to its inability to host any kind of matter" (S013, S421). | None (S013); none but Astral (S421). |
| Astral Plane | An astral form is required (S421). | Arcane magic does not function, for want of a Mithis connection (S421). |
| The Abyss | Material forms may visit and reside (S421). | Divine magic fails for lack of the energy planes (S421); the newer Astral Law account says divine energy is available there (S205). |
| The Void | Material or astral forms (S013). | Not stated. |
| Energy Planes | No known form (S421). | Not applicable. |
Travelling in projection is risky everywhere, because it exposes the traveller to Soul Death.
The reach of Astral Law¶
The newest statement of what governs the planes comes from the magic notes of the Fifth Age layer. "Astral Law is a universal law that governs all of creation, including the Astral, Material, Elemental and Abyssal Planes. However, its power does not extend to the Ethereal, Shadow or Void Planes; as these were not created by the Creators, and have existed since before creation. These planes can be interacted with via Astral Magic, but only inasmuch as they intersect with a plane where Astral Law rules." The same source sorts the focuses of magic to mirror the planes, in three groups: Inner (Positive, Negative, Abyssal), Elemental (Air, Earth, Fire, Water) and Outer (Void, Spirit, Shadow). What Astral Law is, and the sources of power that flow under it, are told on Nature of Magic.
A companion to this rule is the older definition of the "Outside": "any place that is not Terrun and its Inner Planes" (S018). Beings are classed by whether they have a connection to it. Mortals' souls reach the Netherworld; Outsiders reach the outer planes or beyond; creatures of mere essence are connected only to Terrun and its elemental inner planes. See Souls and Spirits.
Earlier accounts¶
The planes have been sorted four ways over the life of the archive.
The Cosmology of 2022 (S013) used four groups: Elemental Planes (Air, Earth, Fire, Water, each with its own rulers); Material Planes, a broad class that held the Prime Material, the Astral Plane, the Abyssal Plane and the Astral Folds (the Rift), because all could be colonised by material life; Transitory Planes, "mostly vast empty spaces between the other planes, filled with some occasional oddities", namely the Shadow Realm, the Sea of Souls and the Fae Realms; and the Outer Planes, which held only the Void. The Revision keeps most of this document's prose but moves the Rift and the Shadow Realm into the inner layers and the Abyss, Netherworld and Astral into the outer planes.
The archive cosmology (S421, S389) had five groups: Elemental Planes; Energy Planes (Negative, Positive and the Mithis Energy Plane); the Material Plane, "the crown jewel of the planes and considered the center of existence"; Transitory Planes (Shadow Realm, Sea of Souls and the Spirit World, by which it meant the Astral Plane), which "all border on the Void and provide a transition from nothingness to the Inner Planes"; and Outer Planes (the Void and the Abyss).
The Compendium (S372, S384) gave only headings: Inner Planes (the Elemental Planes and the Energy Planes), the Material Plane (the Prime Material), Transitive Planes (the Ethereal Plane, the Astral Plane or Astral Sea, and the Shadow Realm) and Outer Planes (the Astral Domains, "The Abyss (Seven Tiers)" and "Heaven (Five Tiers)"). The oldest rules document of all (S371) differed again, treating the Abyss and the Void as Inner Planes reached by Conjuration.
The Nature of Magic (S208) split the planes by the magic that reaches them: the Terrestrial colleges manipulate the Elemental Planes and the Energy Planes of Light and Darkness; the Celestial colleges manipulate "the Outer Planes: Astral, Void, Ethereal and Shadow". The Fae Magic documents (S279, S208) add that the Faerie Plane "binds the Elemental Planes" and the Energy Planes and has no direct connection with the Outer Planes.
The Acadian notes (S358) sketch yet another arrangement, with two crossroads: the Netherworld as "the inner plane crossroads", connecting the Material, the Fae, the Underworld and the Abyss, and the Astral Plane as "the outer plane crossroads", connecting the Material, the Astral Shards, the Void and the Shadow Realms. This note also identifies the Fae plane with the Netherworld; see Fae Realms and Netherworld.
Gap
No source gives the planes' relative sizes beyond the remark that the Elemental Plane is "much smaller than the material plane", and none describes what a traveller sees when crossing from one outer plane to another. The Compendium's "Heaven (Five Tiers)" is a bare heading; nothing says what the five tiers are.