The Great Wheel and Faerun’s World Tree are very similar models based in an otherworldly balance and symmetry. Eberron has its own cosmology that throws those concepts out of the window, keeping the Material Plane at the center of everything, but introducing new ideas such as waning and waxing phases, plane influence among each other and even manifest zones, all of them sources of mystical effects when the DM needs them.
Even heroic tier adventures can venture in planar-related themes and goals, but the mighty inhabitants of otherworldly places should be battled by higher-level PCs. Some of these dimensions are strange places where monsters live and roam while unfamiliar shapes and materials dot the landscape all around. They all have their own dungeons, histories and opportunities for adventure, investigation and even intrigue.
Just like with Planescape’s «Great Wheel» and Faerun’s «World Tree» cosmologies, Eberron’s has the Material Plane at its center and many others around it. That is pretty much the only similarity: In this setting, as the planes draw closer to the material one, they become coterminous. This affects the world, infusing the material plane with different aspects of the plane in such condition. As the same plane becomes remote, Eberron is also affected, as the aspects that embody the plane become subdued. For example, when Risia, the Plain of Ice is coterminous, cold areas become freezing and winters go colder; when it becomes remote, the opposite happens.
These are Eberron’s thirteen planes, their poetic titles and the influence they extend on the world:
- Daanvi, the Perfect Order: peace, stability
- Dal Quor, the Region of Dreams: dreams, nightmares
- Dolurrh, the Realm of the Dead: ghosts, death
- Fernia, the Sea of Fire: fire
- Irian, the Eternal Day: life, vibrancy, intensity
- Kythri, the Churning Chaos: storms
- Lamannia, the Twilight Forest: fertility
- Mabar, the Endless Night: darkness, shadows
- Risia, the Plain of Ice: cold
- Shavarath, the Battleground: war, fury
- Syrania, the Azure Sky: luck
- Thelanis, the Faerie Court: travel, fey
- Xoriat, the Realm of Madness: aberrations
Given how some spell descriptors worked in Third Edition, every cosmology had three planes overlapping the Material one: the Astral Plane, the Ethereal Plane, and the Shadow Plane. Beyond, there were thirteen planes orbiting around. All these were separate from each other, though travel between the planes is possible. They are all connected to the Astral Plane, but were not to the Ethereal Plane or the Plane of Shadow; this had as a consequence that spells that allowed travel to either of those two planes didn’t work when cast on one of the 13 orbiting planes. Wizards of the Coast developed an online orrery for their website. This plugin shows the relative positions of the planes to each other (it requires Adobe Flash, though).
When Fourth Edition came out, many of the magic mechanics changed, including how spells affected or were affected by the planes. The core cosmology got quite simplified, and other cosmologies were given a similar treatment. Fortunately for Eberron fans, waht made its cosmology unique was preserved, although with some minor changes. One of these changes was the Progenitor Myth, which now included all planes and not only the Material one. Some planes exist within Siberys, the Dragon Above (which became the Astral Sea, also called the Sea of Siberys), some within Khyber, the Dragon Below (the Elemental Chaos), and some within Eberron, the Dragon Between (also called the Coils of Eberron). The mystic number 13 was lost as Baator got incorporated, though.
- Siberys, the Dragon Above emcompassed planes that were home to angels and demons: Baator (the Nine Hells), Daanvi, Irian, Lamannia, Mabar, Shavarath, Syrania, and Xoriat.
- Eberron, the Dragon Between had planes overimposed to the prime plane, and got them relabeled to match the required-by-rules Shadowfell and Feywild: Dal Quor, Dolurrh, and Thelanis.
- Khyber, the Dragon Below hosted elemental planes favoring cold, fire and storm: Fernia, Kythri, and Risia.
What I find the most useful about the particular planar array in the Eberron setting is an aspect I haven’t mentioned yet in this article: manifest zones. These are regions who are closer to certain planes, and they exert some degree of influence in the area surrounding them. You can think of them as some sort of planar breaches, but I like to interpret them more as ares that coexist in two planes simultaneously. A very well known (for scholars) manifest zone lies right in Sharn, allowing fantastically high structures to defy gravity.
Smaller and less influential manifest zone exist all around Khorvaire and beyond, and villains are waiting to tap into their power unless they are stopped by brave heroes. The whole thing here is to use them just as you could use hyper powerful rituals or eldritch machines: part of your villain’s master plan in order to achieve their goals. Don’t forget to keep track of the times a plane become coterminous or otherwise your players may notice the lack of a pattern. In case of need, you can always have an opposite and unexpected reaction: instead of the villain taking advantage of a manifest zone to empower a ritual or machine, he’s about to create one.
And since you’re here, and there is a high probability that you like Eberron stuff, I’d like to suggest you to subscribe to the magnificent Manifest Zone podcast. Keith Baker participates regularly, bringing insight into different topics to take your campaign to the next level. Their latest episode is precisely about the content in «Rising from the Last War», so you better start listening and subscribing!
Have you used planes and planar elements in a campaign? What was that like? Open a portal through the comments and tell us everything about it!