Cosmology
Gaea has a unique Cosmology that differs from standard D&D. We do take some basic conventions from the Players Handbook such as the notion of elemental planes (known as The Elemental Wheels in Gaea's cosmology) and transitive planes but generally the public view of the outer realms consists of the material and mortal world and The Unseen, which is the great vast beyond and the spiritual realm where the gods reside. Within The Unseen are countless worlds and the outer planes as Gaea citizens know it.
The Inner Planes
The Inner Planes conform to the standard D&D Cosmology in many ways. For the Inner Planes it is helpful to visualize a crystalline blue globe which is the world, set into the midst of a great expansive sea.
Touching slightly upon the Material Plane are the four elemental planes known as the Elemental Wheels. Spinning eternally, they are Earth and Fire to the left and Water and Air to the right. Occasionally Earth and Fire touch along with Water and Air, creating strange alignments and variations of elemental creatures and events.
Viewed in three dimensions, the Positive and Negative Energy Planes would be respectively above and below the Material Plane. The Positive Energy Plane being that which is most associated with creative forces and good and so reaching up towards the heavens while the Negative Energy Plane, as the opposing force, naturally being aligned with the lower and infernal realms. Some theorize that the Negative Energy Plane is actually a portion of the Void that has made its way into the World and likewise they believe that Positive Energy is, at its core, sourced from the True Source. The great sea in this picture is the boundless Ethereal Sea, sometimes simply referred to as the Deep Ethereal. The other planes in this realm could be seen as an extension of the Ethereal Sea; being the Astral Plane, the Plane of Shadow and the Border Ethereal.
The Astral Plane is the sky, a domain of endless silver that stretches in every direction. The realm between realms, it is what binds all other things together. The Ethereal Plane, sometimes called the Border Ethereal, is an insubstantial realm of ghosts and dreams. Deep within this realm lies the Ivory Dream, where the Dreaming Goddess known as Eluna dwells. The lair of the Enveloper is also within these recesses as well, near to the Material Plane. The Shadow Plane is the realm of darkness that often connects into the Abyss.
Lastly the Sea of Mana is not a true plane in and of itself but rather is much like a greater invisible sea that envelops and binds everything else together and contains it all within it. The Sea of Mana flows from The Source and it brings with it life, energy and miracles. Arcane casting is possible through The Sea of Mana, which wizards know due to their ability to reach out and take from the sea a drop of its power to fuel their spells.
The Outer Planes
The Celestial Realms, the Upper Planes and those lands associated with it are the homes of the gods of light. The Infernal Realms and those planes there are homes to the gods of darkness and also used to imprison powerful beings and contain depraved and dangerous forces. Neutral planes serve varying functions and purposes for the maintaining of the cosmology. Separate from both of these is the True Source and the Nameless Void. Life comes from one and life disappears in the other. Almost every outer plane has divine dwelling places of the deities themselves. These dwelling places tend to function as demiplanes in which servants and petitioners of these gods also dwell. Planes within planes whose existence tends to be permitted by the greater overpower of the larger plane itself. The links below will direct you to a brief synopsis of these planes with basic planar traits and examples of some (but not all) of the sites within the plane. In this case we address the demiplanes that are the homes of some of the deities. In addition to the main outer planes are countless individual demiplanes and separate realities that serve a variety of purposes ranging from universal functions to secret hideaways of insane wizards.
The Planes of Gaea
=Celestial Planes
Neutral Planes
Infernal Planes
Other Planes
Countless shard planes left over from the activities of the gods, other powerful beings and even mighty wizards exist. Some of these shards may be the size of a home and others the size of a small nation. There are countless realms that exist that can be stumbled across and many are the result of natural occurrences and activities between the prime outer planes.
Planar Travel and Adventuring in Other Worlds
Generally, other worldly plots are best left as devices for players with Death Consent status and Dungeon Masters. Mild exceptions may be made with pre-approved player run plots. The people of Gaea have a very limited view of the overall cosmology. Cultural differences, religious beliefs and even implied taboo on messing with the ‘other world’ has made planar travel something that is hardly widely used even amongst the various schools of magic. Despite this, Gaea has had much experience and dealings with the planes and with people’s attempts to use the power found there for their own benefits. Histories such as the rise and fall of Kulthus, the sealing of the still unexplained doorway to heaven and locations on the Material Plane such as the Vast are all evidence of this.
Any Outer Plane is reachable from the Material Plane, with the exception of the Halls of Waiting which is the realm of the dead. To reach the Halls of Waiting, one would need to first journey to an Outer Plane that has an active link to the Halls of Waiting and then use that portal. Travelling between Outer Planes themselves is somewhat more difficult. The Planes are ‘positioned’ based on that particular plane's ‘loyalty’ in the ongoing conflict of good and evil. The top most plane is the Dome of Heaven and the bottom most plane is the Abyss. Naturally one cannot planar jump from the Dome of Heaven to the Abyss and vice versa. Rather the Outer Planes are positioned by allegiance.