Planes of Existence

The Architecture of Existence: A Comprehensive Overview of Eberron's Cosmology

The world of Eberron exists not in isolation, but as the vibrant heart of a unique and dynamic cosmic structure. To understand the fundamental forces that shape our reality, one must grasp the principles governing the Material Plane and its relationship with the myriad other realms.

The Core Planes and the Thirteen Orbits

At the nexus of this cosmic architecture lies the Material Plane, our Eberron. This physical realm is not unbounded, but is meticulously enclosed by three fundamental, yet distinct, transitive planes: the Astral Plane, the very fabric of thought and travel between worlds; the Ethereal Plane, a shimmering reflection of our reality; and the Shadow Plane, a dim, distorted echo.

Crucially, within the vast expanse of the Astral Plane, thirteen other planes of existence maintain their celestial orbits around the Material Plane. These are not static constructs but dynamic entities, each embodying a profound aspect of reality:

• Daanvi, the Perfect Order: A realm of absolute law and unyielding harmony.
• Dal Quor, the Region of Dreams: The elusive, ever-shifting plane of subconscious thought and psychic energy.
• Dolurrh, The Realm of the Dead: The realm where the echoes of life fade, and the dead embark upon their final journey.
• Fernia, the Sea of Fire: A plane of pure elemental combustion, where flame consumes all.
• Irian, the Eternal Day: A realm of boundless light, life, and radiant energy.
• Kythri, the Churning Chaos: An unpredictable plane of raw, unbridled entropy and constant transformation.
• Lamannia, the Twilight Forest: The primordial source of natural life, wild savagery, and elemental essence.
• Mabar, the Endless Night: A plane of consuming darkness, entropy, and the negation of life.
• Risia, the Plain of Ice: A frigid expanse of elemental cold, where motion is slowed and stillness reigns.
• Shavarath, the Battleground: An eternal arena where the forces of good and evil wage ceaseless war.
• Syrania, the Azure Sky: A realm of celestial wisdom, pure air, and the abode of divine beings.
• Thelanis, the Faerie Court: An enchanting plane of ancient stories, primal emotions, and capricious fey.
• Xoriat, the Realm of Madness: A plane of alien geometry and sanity-shattering thoughts, utterly antithetical to mortal reason.

The Progenitor Dragons and Planar Genesis

The precise origins of these planes remain a subject of fervent scholarly debate, though all theories converge on the foundational influence of the Progenitor Dragons. One prevalent theory posits a direct correlation: the planes within the Astral Sea, often termed the Sea of Siberys, are tied to Siberys, the Dragon Above. These include Daanvi, Irian, Lamannia, Mabar, Shavarath, Syrania, and Xoriat, realms often associated with cosmic forces and entities such as celestials and fiends.

The planes known as the "Coils of Eberron"—Dal Quor, Dolurrh, and Thelanis—are speculated to be intrinsically linked to Eberron, the Dragon Between, notable for their infrequent but profound ability to superimpose upon the Material Plane. Finally, Fernia, Kythri, and Risia, exhibiting strong elemental properties of fire, chaos, and ice, are often attributed to Khyber, the Dragon Below, representing the raw, untamed forces of the cosmos.

An alternative hypothesis suggests a more nuanced interaction: that Daanvi, Fernia, and Irian bear the strongest imprint of Siberys, while Kythri, Mabar, and Xoriat are profoundly marked by Khyber. Regardless of the specific attribution, the indelible mark of the Progenitors is undeniable.

Planar Conjunctions: Coterminous and Remote States

A defining characteristic of these thirteen orbiting planes is their dynamic relationship with the Material Plane. As a plane's orbit brings it closer to Eberron, it becomes coterminous. During such periods, the very fabric of Eberron is infused with the essence of that plane. For instance, when Risia, the Plain of Ice, is coterminous, regions of cold on Eberron intensify, frostbite is more severe, and glaciers advance. Conversely, when a plane recedes in its orbit and becomes remote, its influence wanes, and its associated aspects on Eberron become subdued. This ebb and flow creates a constantly shifting magical and environmental landscape.

Mechanisms of Interplanar Travel

While the thirteen planes are distinct, travel between them is possible, primarily facilitated through the Astral Plane. It is crucial to understand that while all thirteen are accessible via the Astral Sea, they are fundamentally cut off from the Ethereal Plane and the Plane of Shadow. This separation renders spells or abilities designed for travel to those two specific planes ineffective when one is operating within the thirteen orbiting realms.

The Cosmic Echo of Progenitor Conflict

The very structure of Eberron's cosmology hearkens back to the foundational myth of the Progenitor Dragons. The epic conflict between Siberys and Khyber, which stretched across existence, concluded with Siberys's defeat and scattering throughout the stars, forming the very Astral Sea itself. Eberron, in an act of profound sacrifice, then encased her malevolent sister, Khyber, within her own being, forming the physical world and imprisoning the Dragon Below within its depths. This primordial struggle is reflected in the planes: Siberys embodying the Dragon Above (the Astral Sea), Khyber representing the Dragon Below, and Eberron stabilizing the Dragon Between (the Material Plane and its closely tied realms). This cosmic history ensures the delicate yet volatile balance that defines our universe.