Beyond this existence of countless planets exist more worlds—entirely different dimensions of reality known as the planes of existence. Except for rare linking points, each plane is effectively its own universe, with its own natural laws. Collectively, the entirety of these other dimensions and planes is known as the Great Beyond.
Although the number of planes is limited only by imagination, they can all be categorized into five general types: the singular Material Plane, its liminal transitive planes, the fragmented Inner Planes, the Outer Planar Wastes, and the countless demiplanes.
The planes are collectively known as the Macrocosm, and form a vast, tangled web of shattered realities. At the heart of the web lies the Material Plane and its conjoined twin the Shadow Plane. These twin planes are bound to the rest by the Ethereal Plane, the threads of which extend through a space refereed to as the Astral Plane, and bind all planes into the Macrocosm. Together the Material, Shadow, and Ethereal Planes are referred to as the Heart of the Web. The Heart is surrounded by the Elemental Planes. Farther out, floating upon the Astral Plane, sits the unimaginably vast Outer Sphere, which is itself surrounded and contained by the innumerable shards of the Abyss.
The Material Plane is the realm of mortal kind and mundane law. It is the center of the Macrocosm, the place where all life flows to and from in the eternal cycle of the ages. Everywhere that is traversable exclusively through the physical laws of reality is contained within the Material Plane. The Material Plane encompasses an entire universe of planets, moons, stars, and galaxies. It is the largest of all planes, being truly infinite in size in spite of being contained within smaller realms. This paradox is made possible due to the differences between the material and immaterial laws of physics.
The Material Plane was once ruled by the powerful outsiders known as Gods, who were opposed by the Deamon Lords of Hell in an etural struggle for power. Then the Z̚oman created the evil nature god Irus, who united the Lords of Hell in his war against the gods. The Gods were all slain, with a few rumored driven into hiding, leaving the Material Plane to be ruled by the countless Kami and a handful of young gods who were trapped within Eyom along with Irus at the end of the War.
These three planes have one important common characteristic: each is used to get from one place to another. The Astral Plane (although technically part of the Outer Planes) is a conduit to all other planes, while the Ethereal Plane and the Shadow Plane both serve as means of transportation within the Material Plane, which they’re connected to. These planes have the strongest regular interaction with the Material Plane and can be accessed using various spells.
As these planes are linked to the Material Plane, they are reflections of it. Complete with biomes, creatures, and laws of physics.
The three major transitive planes are:
A silvery void that connects the Material and Inner Planes to the Outer Planes, the astral plane is the medium through which the souls of the departed travel to the afterlife. A traveler in the Astral Plane sees the plane as a vast empty void periodically dotted with tiny motes of physical reality calved off of the countless planes it overlaps. Powerful spellcasters utilize the Astral Plane for a tiny fraction of a second when they teleport, or they can use it to travel between planes with spells like astral projection.
It is largely intact, in spite of the many battles fought within it during the Irisian War. The most notable damage is to the rivulets through which souls flow to the afterlife. These structures are nearly destroyed and require the god's attention to manage as they are repaired via the construction of artificial canals.
With the destruction of the posative energy plane during the Irisian War, the Astral Plane has become the primary source and conduit for Posative Energy.
The Ethereal Plane is a ghostly realm that exists as a buffer between the Material Plane and the Shadow Plane, overlapping each. A traveler in the Ethereal plane experiences the real world as if the world were an insubstantial ghost, and can move through solid objects without being seen in the real world. Strange creatures dwell in the Ethereal Plane, as well as ghosts and dreams, many of which can sometimes extend their influence into the real world in mysterious and terrifying ways. Powerful spellcasters utilize the Ethereal Plane with spells like blink, etherealness, and ethereal jaunt.
The Irisian War destroyed much of the Ethereal Plane, resulting in many of the denizens of the plane fleeing to the Material Plane. The Ethereal Plane is slowly healing itself, as per its natural laws.
The eerie and deadly Shadow Plane is a grim, colorless “duplicate” of the Material Plane. It overlaps with the Material Plane but is smaller in size, and is in many ways a warped and mocking “reflection” of the Material Plane, infused with negative energy (see Inner Planes) and serving as home for strange monsters like undead shadows and worse. Powerful spellcasters utilize the Shadow Plane to swiftly travel immense distances on the Material Plane with shadow walk, or draw upon the mutable essence of the Shadow Plane to create quasi-real effects and creatures with spells like shadow evocation or shades.
With the destruction of the negative energy plane during the Irisian War, the Shadow Plane has become the primary source and conduit for Negative Energy. This greatly affected undead, changing many of their properties. Most notably, granting all undead the ability to see the very souls of the living and permitting the majority of undead to possess free will.
The Shadow Plane was also damaged during the Irisian War in such a way as to cause rifts to and from the plane to tangibly manifest in the Material Plane. This both strengthened the link between the Planes and also causes certain monsters with ties to the Shadow Plane to spontaneously spawn from thin air and Shadow essence leaking into the Material from the rifts.
These six planes are manifestations of the basic building blocks of the universe. Each is made up of a single type of energy or element that overwhelms all others. The natives of a particular Inner Planes are made of the same energy or element as the plane itself. The Negative Energy Plane, the Positive Energy Plane, the Plane of Air, the Plane of Earth, the Plane of Fire, and the Plane of Water are all Inner Planes.
The Inner Planes contain the building blocks of reality—it’s easiest to envision these planes as “containing” the Material Plane, but they do not overlap with the Material Plane as do the transitive planes. The natives of a particular Inner Planes are made of the same energy or element as the plane itself. The Inner Planes are:
The most well known Inner Planes are the Plane of Air, the Plane of Earth, the Plane of Fire, and the Plane of Water—it is from these planes that the creatures known as elementals hail, yet they house many other strange denizens as well, such as the genie races, strange metal-eating xorns, unseen invisible stalkers, and mischievous mephits.
The Elemental Planes survived the Irisian War, but many of their denizens fled to the Material Plane as refugees, where they remain to this day.
The Positive Energy Plane and the Negative Energy Plane were destroyed during the Irisian War when Irus pulled them into each other in an attempt to annihilate the Triumverate in a single stroke. The Macrocosum itself rearranged to compensate for their destruction, causing the Shadow Plane to become the new source of Negative Energy, and the Astral Plane to become the new source of Posative Energy. Clerics utilize power from these planes when they channel energy.
Beyond the realm of the mortal world, beyond the building blocks of reality, lie the Outer Planes. Comprised of an infinite number of finite planes, it is to these realms that the souls of the dead once traveled, and it is upon these realms in which the gods themselves once held court. The Outer Planes were devastated during the Irisian War, with most being smashed into countless demiplanes as their masters fell in battle.
Each of the Outer Planes has an alignment, representing a particular moral or ethical outlook, and the natives of each plane tend to behave in agreement with that plane’s alignment. The denizens of the Outer Planes form the mythologies of civilization, comprising angels and demons, titans and devils, and countless other incarnations of possibility. The Outer Planes were once the final resting place of souls from the Material Plane, and thus the dead can be found in these realms, surviving their eternities with the Planar natives as best their shard permits.
Powerful spellcasters can contact the Outer Planes for advice or guidance with spells like commune and contact outer plane, or can conjure allies with spells like planar ally or summon monster. Of course, the odds of finding anyone left to listen to their words is quite low. The vast majority of spellcasters instead direct their messages to specific locations on the Material Plane, where the Kami related to their inquiry resides.
The deities live on the Outer Planes, as do creatures such as celestials, fiends, and other outsiders. Outer Planes include: Abaddon, the Abyss, Elysium, Heaven, Hell, Limbo, Nirvana, Purgatory, and Utopia are all Outer Planes.
Shards of these Planes can be found drifting in the Astral Plane.
This catchall category covers all extradimensional spaces that function like planes but have a measurable size and limited access. Other kinds of planes are theoretically infinite in size, but a demiplane might be only a few hundred feet across. There are countless demiplanes adrift in the Macrocosm, and while most are connected to the Astral Plane and Ethereal Plane, some are cut off entirely from the transitive planes and can only be accessed by well-hidden portals or obscure magic spells.
The planes of the Inner Sphere and the Outer Sphere form the overarching structure of the multiverse. Their unimaginably ancient histories and vast scales contain most of reality within their borders. Yet the dimensions of reality are not static, particularly in the Astral and Ethereal Planes, which serve to connect the other planes. Under the right conditions, any plane can warp so profoundly that portions coalesce into entirely new planes. These selfcontained pockets of reality are known as demiplanes.
A typical demiplane is a relatively small, finite plane governed by its own set of laws determined upon its creation.
Some of these pocket dimensions owe their existence to the collision of natural forces within other planes. The Shadow and Astral Planes exert powerful tidal forces upon the Ethereal Plane, generating ethereal mists. However, these forces are not perfectly synchronized, and when the strain from opposing forces grows too great, the Ethereal Plane sometimes releases energy by coalescing ethereal mists into a demiplane. Occasionally, instead of forming a new demiplane, these mists graft themselves onto an existing demiplane, which expands to accommodate the new material.
Meanwhile, in the Astral Plane, the ever-shifting currents of the River of Souls combine with energy from the Outter Planes shards and the Plane of Fire to produce massive, hurricane-like astral storms. Like hurricanes on Eyom, these storms have stable eyes at their centers. When conditions are right, the Astral Storm can release some of a storm’s energy by creating a demiplane in its eye. These demiplanes can grow over time as they absorb storm-tossed fragments of the Astral Plane into their mutable structures. Astral and ethereal demiplanes are similar in structure, though the differences in their creation leave lingering effects. Because of the role of currents on the River of Souls in their creation, astral demiplanes bear fragments of the nature and memories of passing souls.
Ethereal demiplanes can absorb echoes of dreams, most commonly from the Matrial Plane's denizens but the dreams of all beings flow from the ethereal. In the absence of outside interference, these lingering fragments determine the demiplane’s properties and characteristics.
While some demiplanes arise from planar forces, others are born when individuals deliberately fracture pieces of the Astral or Ethereal Planes and reshape them into pocket dimensions to suit their needs. Even mortals can weave demiplanes into existence with complex rituals or powerful magic. Demiplanes serve as ideal, protected havens for experiments, as well as for manipulations of time and space that would prove difficult or impossible to produce in other places.
Most Kami live within their own personal Demiplanes, which are anchored to the Material Plane by some structure. In Eyom, Kami exclusively anchor their demiplanes via small cabin-like houses (often irreverently referred to as Kami Houses) and simply link their home to their shrines for communication purposes. In the rest of the world, the anchor is always a shrine.
The true definition of a demiplane is a matter of debate. In its most restrictive definition, only self-contained pockets of reality formed from the Astral or Ethereal Planes and accessible via typical methods of planar travel—such as plane shift—qualify. This definition excludes Eyom itself, which is sealed off from the outside world via the God Wall, and possesses notably different arcane laws from the rest of the Material Plane. It is, by many definitions, a demiplane. However as it specifically serves as a prison for the god Irus, many scholars believe it should be classified as just that, a god's prison.
Scholar's Note: Evidence suggests ancient bags of holding and similar items made use of the Atherial Plane rather than demiplanes. Consequently, they did not need frequent charging. They did however, explode when interacting. One presumes there were no safety standards organizations in those days.
Two planes that are separate do not overlap or directly connect to each other. They are like planets in different orbits. The only way to get from one separate plane to the other is to go through a third plane, such as a Transitive Plane. Planes are connected in one of the following ways:
Planes that touch at specific points are coterminous. Where they touch, a connection exists, and travelers can leave one reality behind and enter the other. Most planes are coterminous, though few planes intersect more than three others.
If a link between two planes can be created at any point, the two planes are coexistent. These planes overlap each other completely. A coexistent plane can be reached from anywhere on the plane it overlaps. When moving on a coexistent plane, it is often possible to see into or interact with the plane with which it coexists.
It is well known amongst scholars that there are Macrocosms other than our own. These realities exist as countless bubbles within a thick sea of aether. Our Macrocosm is not a part of this sea. It was cast out of the waters and onto the shore at the end of the Irisian War by the gods of the other realities. So great was their fear of Irus, that they ensured he could never reach their realms no matter how hard he, nor anyone else, tried.
These places and planes are forever beyond our reach. Just as one cannot walk to the sun because no ground exists on which to walk, one cannot leave our realm for another. There simply is no means to do so. Our realm rests in a great dry gulch, devoid of not only aether but of space and time itself.
Many scholars maintain the hope that one day a means of at least observing the other realms might be devised, however, as long as Irus lives, our realm must remain lost to all others for the good of all, mortal or immortal.