Adventure Luna 4 ~Rebirth~
Thanks to extensive magical research, primarily by espers, it has been discovered that reality is divided into layers, and the material plane is but one of many. However, these other realms are wholly unlike the stable and reliable material plane and are not governed by the same laws of nature.
The Material Plane
This is the layer of reality with which mortals are most familiar, and is the most stable and reliable in structure and nature. A force called aether — which is used in the casting of spells and other superhuman abilities — permeates this reality, and is thought to originate in the Astral Realm, seeping through where the barrier between realms is thin.
The Astral Realm
This is a luminous, spacious realm of spiritual energy and is thought to be where the souls of the living travel after death, when their lifeforce — thought to be what anchors them to the Material Plane — is snuffed out. Powerful mages who have traveled to the Astral Realm have written that they have seen the souls of the recently dead as vaguely humanoid shapes, coalescing as they travel in great streams called lifestreams toward a distant light.
The Great Beyond
This place is visible from the Astral Realm at first as a distant but bright light, but on approaching, it appears as a brilliant luminous wall of immeasurable size, stretching off in all directions, with innumerable vast lifestreams flowing into it. No astral explorer who has entered the Great Beyond has ever returned from it, no matter their magical might or knowledge or skill, hence its name. It is thought to be the final destination of all souls, but its purpose and function is otherwise unknown, and no lifestreams have been witnessed flowing away from it.
While traveling in the Astral Realm, explorers feel a spiritual pull leading them back to the Material Plane, but the closer they get to the Great Beyond, the weaker this pull becomes. As they near the Great Beyond, they can feel the light pulling them away from reality and into it. Curiously, spells used to communicate also become weaker with proximity to the wall of light.
The Void is thought to be the realm between realms, a place of transition and chaos. There are pockets of stability within the Void, and strange creatures lurk there. When the barrier between the realms becomes thin, Voidsent can break through to the Material Plane, where they’re able to wreak havoc and indulge their chaotic and unknowable urges.
All spells that involve teleportation, summoning, and travel between Planes touch the Void in some way, however briefly, and this makes these spells a sometimes risky proposition. This is why these spells are closely guarded and only taught to the most skilled and reliable mages.
These strange creatures come in wildly differing shapes and sizes, but all seem to share a taste for the flesh and blood of the living, even if their strange and sometimes impossible anatomies don’t seem to support a digestive system. Some appear as twisted mockeries of known creatures, while others are wholly alien.
These islands of stability within the Void appear as chunks of land upon which are built towns and cities, all crumbling with age, many warped by the Void’s chaotic aether. Some are teeming with Voidsent, while others are bizarrely empty and devoid of any life whatsoever. The true nature and origin of these places is unknown.
The Near Void and the Deep Void
Similar to travel between the Astral Realm and the Great Beyond, the Void has a metaphysical depth that has been observed with extensive travel. The Near Void is the region touched briefly by teleportation magic and where the majority of Void Realms can be found. As one travels deeper, Void Realms become fewer in number and the laws of nature become less stable and reliable. What has a reproducible effect in the Near Void might have an entirely different effect — every single time — in the Deep Void, resulting in chaotic regions where the laws of nature become so twisted that they are outright hostile to life.
These realms exist as extensions of the natural world, where the power of nature becomes so strong that it spreads across the planar boundaries and creates a small realm of its own. This can only happen in places of immense natural power where one force is dominant over others, such as glaciers, volcanoes, high mountains, deep forests, and ocean trenches. To enter them, one must travel to the place where the region’s aether gathers, and then use rituals or magic to cross the planar boundaries.
The realm beyond exists as a magnified reflection of the region in the Material Plane; mountains are grander, trees are larger, lava flows hotter and faster, blizzards blow harder, and so on. These realms are where elementals hail from, formed whole from the fabric of the realm itself, imbued with and composed of nature’s power.
The Dream Realm
The Realm of Dreams is metaphysically very close to and often overlaps with the Material Plane, and is theorized to be created by the collective consciousness of the living. It exists as a hazy, indistinct, and warped version of the Material Plane, but its landscape changes as living creatures sleep and dream.
Each dream creates a region in the Dream Realm that from the outside resembles a bubble. The greater a creature’s intellect and power, the larger the dream bubble appears. On the inside, however, exists the entirety of the creature’s dream. Only through the use of magic can a creature travel to the Dream Realm and enter dreams.