Homeland: The Planes

Inhabitants of the Homeland rarely travel to or through the planes, with the sole exception of the teleportation magic used by the Wayfarer's Guild. Even the highest and most powerful magisters hesitate to cross planar boundaries; there are hazards in the planes which even the mightiest should fear. However, courageous (and foolhardy) explorers have returned with a wealth of knowledge over the twenty-six centuries of the Magisterium.

The Prime
The Prime, a common contraction for the "Prime Material Plane," is the plane on which the world of the Homeland resides. The Prime is not the largest of the planes, but it is still vast, containing the stellar system of an entire world and possibly other systems entirely. The Magisterium's School of Cosmology has waged bitter academic wars over whether flight through the empty space beyond the world's atmosphere would lead to another plane or whether it would simply take the flier through unexplored regions of the Prime. Experimental proposals to investigate this scenario have been routinely denied on the grounds that they are costly and ridiculous.

The Shadow
The Shadow is best understood as the home of the reflection in the mirror. It is an inversion of reality which exists adjacent and coterminus to the Prime. The Shadow contains a reflection of every permanent thing that exists in the Prime, but like any other reflection, these copies may be distorted or twisted. For these reasons, the Shadow is inimical to life as it exists on the other planes. It does have beings which are native to its warped environs, but these creatures are extraordinarily dangerous to the normal creatures that inhabit the rest of the universe. The Shadow is malleable in strange and sometimes contradictory ways, a property which has been used in some spells to facilitate rapid travel through the Prime by forcing the Shadow to create shortcuts. However, such magic can be risky, and living creatures should not stay in the Shadow any longer than necessary.

The Astral Sea
While the Prime is incredibly large, the Astral Sea makes it seem the merest dust mote next to a mountain. The Astral Sea is inconceivably vast; indeed, it may be indefinitely vast, for it is a transdimensional space rather than a true plane. The Astral Sea is the etheric medium that connects every known plane, but each plane is miniscule beside the Sea. All planar travel, apart from that between the Prime and the Shadow, must cross the Astral Sea.

The Sea itself is mostly empty space, though most of the physical laws that operate on true planes do not apply. Creatures do not age, eat, drink, or breathe, time does not pass as such, and movement is impossible. This has suggested many possible applications, which have been unfortunately rendered moot by the fact that most beings go mad in short order if exposed to the Astral Sea without adequate protection. The necessary protections impose a frame of reference that contextualizes reality; this prevents madness, but also reimposes the physical laws whose absence might otherwise be exploited.

The Feywild
Where the Shadow reflects the Prime, the Feywild parallels it. It is in most respects like the Prime, albeit substantially more rugged and wild, nature unconstrained by civilization. It is also an arcane sinkhole, where magical power gathers and pools. Some scholars believe that the Feywild is the source of arcane magic, just as Celestia is presumed to be the source of divine magic. Unfortunately, efforts to learn more have been largely foiled by the Feywild's rulers, the faerie.

The faerie are the unconstested masters of the entire plane. Their society is riven with strife and division, but all are quite alien to the mortals of the Prime, and none look upon mortals with any real kindness. The friendliest of the faerie lords view mortals as pitiable animals scarcely worth the effort to manipulate and exploit. The elves are particularly despised for their collective decision to abandon the Feywild and take refuge on the Prime. Mortals have made deals with the faerie in the past, but most find that the cost of their bargain is higher than the reward.

The Elemental Confluence
As even children know, the world holds four elements in balance: air, earth, fire, and water. These four are intermingled in different measures throughout the Prime. However, through a mechanism that not even theologians have been able to adequately explain, the elements never seem to unbalance. The Prime always maintains a perfectly stable balance between the four elements. Instead, whenever one element's power surges and waxes, the excess energy drains off into the Astral Sea. Over time, this resulted in a pooling of elemental energies: the Elemental Confluence.

Unlike the Prime, where the energies of each element are balanced, the Elemental Confluence segregates them. One quarter of the plane is aligned with each element. Where all four quarters meet in the center of the plane, a stable land - the Unity - has formed which is broadly similar to the Prime. The farther from the Unity one travels, the more pure each element becomes. Elemental beings of all sorts have established homes throughout their respective quarters of the Confluence. The Elemental Confluence receives the most visitors from the Prime apart from the Shadow, and some elementals have built friendly relationships with mortals and the Magisterium.

Celestia
The putative home of the Gods of the Circle, Celestia is nonetheless unwelcoming to visitors. The gods, it seems, do not like to be disturbed. Beings who claim to be the reincarnated souls of the saints have been encountered in Celestia, but they too are reclusive and disinclined to speak to mortals. Physically, Celestia is incredibly varied, for its physical laws may be altered by concentrated willpower. The few explorers who have attempted combat with the angelic inhabitants of the plane quickly discovered that their own will was little match for the mental strength of an archon, and that physical strength was meaningless when your opponent can subject your body to vacuum pressures with a thought. More thoughtfully applied will has allowed the Celestials to grow odd and idiosyncratic homes to (incredibly erratic) personal tastes.

The Abyss
The Abyss is just as variable as Celestia, if for different reasons. The Abyss is the home of demons. The smallest of the planes, it is also the most violent and chaotic, for its inhabitants are constantly at war. For the last two thousand years the demon lord Asmodean has ruled the Abyss, but he faces constant treachery from his vassals, each of whom also competes with the others for primacy. The result is a world where peace is the interval between attempted genocide. No mortal knows what the Abyss looked like when the universe was new; today, it is a hell, brutally ravaged by magical war. Every abomination and desecration imaginable may be found somewhere in the plane. At least, so it is believed - few explorers have even made the attempt to map the Abyss, and fewer still have survived.

The Void
Vast though it is, the Astral Sea has its limits. Eventually, the blue-grey mists of the Sea fade into pure nothingness - the Void. What lies in the Void, or perhaps beyond the Void, is utterly unknown. All magic that crosses between planes relies on using the Astral Sea as a medium. Without the Sea to channel the magic, the Void is impenetrable.