|Heroic Action Role-Play|
While normally a campaign specific thing, some kind of core cosmology helps us to understand the Action rules.
In Action the basic cosmology has different planes lined up next to each other as if on a string. This string has the present game world in the middle. To one side lie the material worlds and elemental planes - realms of matter and substance. This is sometimes called the inner planes or the ethereal realm. On the other side lies the realms of ideas, dream worlds, and the heavens and havens of different religions. This can be called the outer planes or astral realm.
This "string" is called the Axis Mundi. On way to think of this is as a 5th dimension (separate from the three normal spatial dimensions and time), that can only be traveled along using mystical means. By going "deeper" or "stepping sideways", a character can distance himself from normal reality without physically moving in normal four-dimensional space.
Each world occupies a position along this string. Sometimes, several worlds can be equally distant from the prime and still be separate, but generally, each spot along the Axis Mundi holds a single plane or realm. In one direction lines planes that have a higher degree of physical reality, but a lower degree of complexity or spiritual reality. These are called ethereal or elemental planes. In the other direction lies planes of less physical and more spiritual nature. These planes are called heavens, afterworlds, or astral space.
The Axis Mundi is a linear scale with two directions. Prime is in the middle (at zero). Material/Ethereal planes have negative values, while spiritual/astral realms have positive values. Higher absolute numbers means the plane in question is further from the Prime and generally more extreme and different.
Note that this scale is arbitrary; it could just as well be reversed, or centered somewhere else. But as the Axis Mundi has no firm endpoints, it is a practical way for prime beings to understand the orientation of the cosmology. Creatures and civilizations from other places along the Axis Mundi might use their own homes as point zero, and still arrive at mostly the same results.
Note that not all of the Axis Mundi is occupied - there are stretches of it that are simply empty, where only the Aether exists. This is an empty, hostile place to be. There are also soft spots in the various worlds, "bulges" where a world is bent along the Axis Mundi and thus closer than usual to either the astral or ethereal. Such places are often good starting points for planar expeditions, and some even transport creatures randomly between planes.
This is the game world where most of the action happens. It is situated on the neutral point between the ethereal and astral, and gets many of its unique features from the balance of matter and ideas.
The prime is surrounded by the shell, a barrier that prevents the outer realm from mixing in with the prime reality. Different worlds have shells of different strengths, and a stronger shell bars more interdimentional transfers, making the use of supernatural power that much harder.
Surrounding all of this is the etheral or astral plane, two names for the very same thing. The unified term for this here is the aether. This is the medium trough which all inter-dimensional travel must pass, and this includes most supernatural powers that act as conduits for planar powers. The aether is formless and lacks features. In ethereal realms it is grainy and feels somewhat like a bog; moving trough the deep ether is like swimming in quicksand. In the astral realms it is clear and sharp, but everything appears remote and distant, like stars in the sky. Approaching an astral realm, the barrier is a glowing wall of mist or the shiny surface of a star even further out.
The aether is a dull place, not conductive to life or meaning; it is a conduit between places rather than a place itself. It is possible to construct places here, but these tend to confirm to either the Dreamlands or the Elemental Chaos, respectively and are not truly of the aether.
The Inner Planes
Traveling "down" the Axis Mundi - towards more negative values - you come to the material planes. These are the source of the matter and energy that make up the Prime, but the further you go, the more raw and chaotic these places become and the less meaning and organization there is. Those ethereal realms closest to the Prime are habitable, but as you go further away the mixture of different elements becomes more and more spotty and chaotic. Large chunks of raw elemental energies or clumps of raw matter are not good places for Prime beings to live. The creatures encountered become less and less anthropomorphic, less and less comprehensible, and more and more willfully destructive as you go.
The closest of the elemental realms is faery, a plane similar to our own, but governed less by reason and psyche and more by raw urges and elemental powers. Faery appears like a more fantastic version of our world; forests are greener, mountains higher, seas bluer and stormier. Changes in the Prime are mirrored in faery, but generally with a long lag; faery resembles the Prime as it was decades or centuries ago.
Closely linked to Faery, these "deeper regions" are even more wild and unpredictable than normal, and they no longer mirror the Prime. Realms here are often sources of power connected to natural phenomena; there are places like the Winter Palace, Summer Glen, Storm Mountain, and similar more-than-natural sites. Such places tend to be the home of strange fey princes and monsters with little love for the Prime and little regard for the higher realms. The lords of such places gain strange powers related to the nature of the domain, and there are often local magical rules as well.
Beyond deep faery, the ethereal realm breaks up - there are areas of pure elemental forces. These include the classic elements; earth, water, air, and fire as well as positive and negative energy "poles" that are a source of life and undeath, respectively. All kinds of strange mixtures exist here too, but these worlds seem incomplete and half-finished to someone from the Prime.
At the far end of the elemental chaos (some call it the centre of it) lies the Abyss, the primal cosmic whirlpool from which all matter comes, but which also dissolves all order and reduces all meaning to nothing.
Traveling "up" the Axis Mundi, you find places that are more and more idealized, but at the same time less and less real. To begin with there is almost as much a mix of matter and forms as on the Prime, but slowly it polarizes into different realms for different ideas - and these areas cannot tolerate any nonconformity.
The closest of the higher realms appears as a dim version of the Prime, almost indistinguishable form the real thing and mirroring physical reality. As opposed to Faery, this realm has a futuristic look, representing the dreams and future visions of people from the Prime. Large areas of the Next World are city-scapes, and more advanced than the cities of the prime in both size and scope. But there are also regions of perfect wilderness as well as natural places of soul-wrenching beauty.
The recently dead pass these regions on their way to the afterlife, and many linger here for a while, making this a place of shades and ghosts. The good dead usually pass on quicker, while the evil dead are reluctant to go to their eternal reward, so most of the spirits found here are malignant or lost.
Land of Mists
Deeper regions of the Next World appear solid and real, but are actually playgrounds for powerful or obsessed spirits, either dead or who find their way here when the Prime was no longer sufficed for them to express their egos. Each such realm is separated by mists - seemingly ordinary, but impenetrable to all senses and most mystic powers. Effectively, each realm within the mists is a separate mini-reality, usually governed by its own egotistical lord and is a manifestation of the lord's subconscious. Such a realm exists and disintegrates with it's lord, disappearing into the mists when there is no strong will to force the realm to stay constant.
It is possible to learn the paths trough the mists, traveling from one shadow realm to another with some certainty. Sometimes such a passage becomes so well established that anyone can traverse it, and the mists become transparent and barely noticeable, creating countries and continents within the Land of Mists. But such regions are never stable - they can disappear by the whim of a ruler or just drift apart again.
Beyond the Land of Mists lies the dreamlands - even more temporary. Every dream ever dreamed takes place here, and the realms can change just as quickly as a dream can. Few travelers come here except to explore the dream-conscious of someone on their home plane. Some creatures have built homes for themselves here, mostly exiles from the prime who found their ideas diverged so strongly from consensual reality that they could no longer survive there. Mages build themselves sanctums here, places of retreat where no-one will ever intrude.
This is the realms of the greatest spirits of all - the gods and devils that capture and channel the imaginations of multitudes of prime beings. This is where the faithful dead find their final reward or punishment. Each such haven is home to one or more powerful spirits, and these lords can dictate how reality works in their realm. Because these spirits are so powerful, their realms appear much more lasting than those of the Land of Mists. But in actuality, the lords of these realms can change things at whim, and the inhabitant survive only on the mercy of their ruler. Acting out ideas not included in the though of the rulers here is very difficult - which is rarely a problem, as those who reach these places are strongly in tune with the ideals they express.
The third cosmic power that influences creation, a third direction in the Aether if you will, is the Void. This realm is essentially alien, represents an alternate Axis Mundi, a different blueprint for reality. In the Void, there are no barriers or limitations on what an individual psyche can achieve. No benchmarks or racial limits. Reality is both mutable and physical at once. This means that powerful psyches can dominate their surroundings totally, mastering and enslaving lesser wills by their mere presence. Unlike the Astral realms, which are governed by eternal truths, the Void is governed by whim and cults of personality.
The Void borders the material world in different areas, alien places where the norms and laws of physical existence are weak.
The most commonly encountered borderland between the Prime and The Void is the Netherworld, a subterranean land of tunnels and lost worlds. Those that explore caves and tunnels often report that there is a lower level to these places, a dimly illuminated land of tunnels and halls that defy rational explanation. Surface dwellers, even entire races like the drow, are attracted to this place by strange and wondrous treasures and magics.
The Lightless Depths
Below the sane seas where merfolk and fish dwell there are deeper realms, unknown and unexplored. This is the home of giant squids and kraken, but also of the aboleths and other cosmic horrors. What few realize is that this is another borderland of the Void, a land of eternal darkness where the rational rules of the universe no longer apply.
The third border region of the Void is in out in the empty depths of space. While planets and sometimes entire solar systems can be Void realms, the most frightening part of deep space is the emptiness - an endless nothingness, where causality and time collapses.
The Outer Void
Beyond the border regions lies the further or outer void. This is actually not one realm, but many. The different Old Ones and Outer Gods have their personal realms here, and each of these realms is much like an entire Axis Mundi in itself, a collapsed reality where no will but that of the ruler no longer has any say. Travel to the Outer Void is dangerous in the extreme, and usually happens by accident rather than design.
Rules & Consequences
Much of the difference between places are mainly cosmetic and atmospheric. Often simply describing ethereal places as raw, magnificent, overpowering and astral places as sublime, ideal, and ephemeral the correct mood can be created. Still, some things do change from the ethereal to the astral realms.
- FX: Effects tend to be more obvious and spectacular in ethereal realms. Showers of sparks, tornadoes of energy, and tides of radiant light are typical. In the astral realms, side effects are more subtle in nature; moods and hints replace in-your-face obviousness.
- Duration Effects, especially physical effects, tend to last longer in ethereal realms. A fireball continues to glow and smother and might even linger for some time. In astral realms, physical effects are very temporary, almost unreal while moods and suggestions gain a measure of reality they don't have in the prime.
- Environment In both ethereal and astral realms, physical reality takes on a power and stability it does not have in prime, but for entirely different reasons. A fireball that on prime would leave a burnt mark on the ground has less environmental impact at either end of the Axis Mundi. This adds subtly to the supernatural feeling of these alien places. In ethereal realms, physical reality is more real and resistant to impact than in prime. In astral realms, physical reality is ephemeral, and unless whoever controls the local reality acknowledges the impact of environmental effects, they fade away very quickly.
- Teleportation It is harder to teleport in ethereal realms; reality there is more static and resistant to such drastic changes. Often, a teleport in ethereal space end up at a fixed spot or gateway. Teleportation is easy in astral realms, you can move from one place to another like a thought. But whoever controls local reality might set up barriers that are hard to cross, especially in the Land of Mist.
- Conjuration, the summoning of elemental effects, are easier in ethereal space. While it is hard to change the local environment, there are lots of nearby elemental energies to draw upon. This makes the summoning of elemental creatures easy, and summoned elementals are cooperative. In astral space, it is easier to summon and gain the cooperation of non-elemental creatures, such as devils and angels.
- Death Outside of Prime, death is less real and less permanent. In the ethereal, a spirit whose body is destroyed can usually form a new one, even if it might reincarnate in an unpleasant place and the new body is often colored by the environment or your subconscious. Inner attributes become visible physical attributes. In astral space, creatures can continue to function even when their physical form is disrupted; if their motivation is strong enough they can re-animate their own remains as wights or return as ghosts, retaining this form as long as they have a strong enough motivation.