Central to the observable existence is the prime material plane, wherein the realms of Shadow and other nearby continents lie. This plane is overlapped by the Ethereal, Shadow, and Feywild planes, and all are bordered by the Astral plane. Through the Astral, the Inner and Outer planes are accessible. What lies beyond is the subject of ancient and forgotten knowledge. All planes exist within the tapestry of the Void, like islands in a vast ocean.
A plane of ghosts and horrors, and a means to travel within the material plane or step The Ethereal Plane – A plane of ghosts and horrors, and the means of traveling within the prime material plane by stepping out of alignment with it. Blink, displacement, and phasing spells and powers utilize this plane in their operation.
Less a plane unto itself and more of a boundary between the transitive planes and the rest of the cosmos. It is relatively empty and timeless, but is the means through which travel to other planes is achieved. Planar gates and similar powers use the astral plane to bridge pathways between different planes.
The first plane, the birth of all life and creation. It is steeped in positive and radiant energies, and the original home of the Fey. The plane is covered in wild and varied vegetation, constantly in flux to the whims of the Arch Fey that is bound to the local territory. So flush with radiance is the plane that it never truly becomes night, merely bordering on twilight. In the deep forest, though, far below the canopies where the light grows dim or is silenced altogether, the void has begun to quietly twist and corrupt the plane. While the Summer Court (Seelie) embrace the warmth of radiance, the Winter Court (Unseelie) are darker beings, prone to violence and cruelty.
Shortly after the birth of the Feywild, the Shadowfell came into existence like a dark reflection. The dark energies of the void gather here, roiling and coalescing into a dark version of the Feywild. Where the Feywild creates and blossoms, the Shadowfell twists and tears apart, a bastion of entropy. Pools of negative energy well up throughout the plane, providing the source that all undead creatures draw from to create their sickening mockery of life.
This is the nexus between the Feywild and the Shadowfell, a place influenced by both to create a middle ground of existence. Creation blooms, but is held in check by entropy and destruction, nether force gaining the upper hand.
These are the four elemental planes – air, earth, fire, and water – accessible from the prime material plane via the astral plane. A few tangible cross-points exist on the prime material plane, allowing regular travel to and from some of the inner planes. Beyond these portals, powerful magic must be used to travel to these planes.
Many outer planes exist, although scholars still debate to this day as to their exact number and nature. Such planes are the realms of deities, demons, celestials, devils, and the many splendors and horrors that lie between. Certainly reason would suggest that planes such as these must exist to encompass all deities, alignments, and natures in some form. Amongst these also lies The Deathless Plane, where the souls of the dead are drawn through the astral plane to await Lysara's judgment.
Demi-planes are usually only small, and are physically created by a deity or a powerful spell caster. Countless exist, popping into and out of existence, created by spells such as rope trick or in the creation of enchanted items like bags of holding. Larger, artificially made demi-planes also exist, but require immense power and knowledge of the arcane.
The basics of fire, water, earth, and air, these energies merge into an array of para-elemetal energies like steam and lava. It is these elements that comprise most of the other planes in various levels, creating the firmament that life is built upon. These are primal forces that were the first to be realized after the spark of Radiance drove back the Void in the birth of the Feywild.
The energy of life and healing, it is most abundant in the Feywild but springs forth in most planes as life grows and spreads. Where the Radiance provides a space for life, positive energy is what fuels it. It reacts destructively against it's opposite, tearing anything apart that is animated by negative energy. Many scholars consider positive energy to also be a primal force, as its presence coincided with the birth of the Feywild.
The twisted mockery of positive energy, this power is drawn from fonts within the Shadowfell and channeled in order to create undeath. It corrupts and poisons anything fueled by positive energy, as the two cannot coexist. It is often considered a secondary force, as it only came into being as a reaction of the Void, mimicking the positive energy of the Feywild in a twisted reflection. While negative energy can be tapped into by those seeking power, it always results in undeath if it contaminates a vessel.
The light of the stars, searing through the darkness of the Void. Each plane in existence, barring the Shadowfell, is only able to exist because of the presence of this energy. Its burning light drives back the Void and creates an oasis in the darkness for that plane to exist. Mages and other learned practitioners of magic utilize small sparks of such energy when creating demi-planes, though Radiance has been know to spontaneously appear through unknown means, explosively coming into existence and destructively carving out space in the shadowy Void.
It is the force that surrounds everything in the cosmos, the slow entropy that drags existence into destruction and nothingness. From the moment Radiance first came into being with the birth of the Feywild, the Void has sought out weaknesses and cracks in every plane, tearing apart their defenses through inexorable and insidious channels in order to snuff the Radiant light and reclaim its lost territory. It is the source of the shadow weave, often tapped into through dark and bloody rituals, and is another pathway to power through nefarious means. However, drawing on the power of the Void is not taken lightly except by the foolish and always brings repercussions.
At their nature, both the Radiance and the Void do not act through any intelligence or strategy, but they are both bound to Edea and Ashra who were born of these primordial forces. It is through them that the war between the light and the darkness is waged.