Taking my inspiration from Nordic myth, I decided on nine inter-connected planes. Looking at a* list of the Nine Worlds gives us
- Midgard, the campaign world
- Asgard, the divine world, risen afterlife
- Vanaheim, the second divine world
- Jotunheim, the giant world of primal nature
- Muspelheim, the primordial fire world
- Niflheim, the primordial ice world
- Alfheim, the elf world
- Nidavellir, the dwarf world
- Hel, the netherworld, fallen afterlife
Thinking about this, and keeping mind some other ideas I had previously about alternate realities / dimensions I came up with the following;
Kherindal - The campaign world, fairly typical Terran world with magic and super-science. Notable for the large number of sapient races. (Life Evolves)
Salandron - A place of
fire, earth, air, but no water. The City of Brass is here, along with literal firestorms, slag rats, thoqqua, and ironwood dhows sailing of seas of pitch and oil. Innately hostile to terrestrial life. Yet, those that can survive can barter for pleasures that can satiate any desire, subtle or gross. But beware for the ifrit hunger for slaves to work in this most inhospitable world. (Fire Consumes)
Vaalbaran - A place of
water, earth, air, but no fire. This is an empty, lightless waste of stone, ice, and gloom, an echo of the time before Creation. Emotionless intellects from deep time lurk here contemplating ineffable philosophies for eons. They do not take kindly to interruptions, but, oh, the questions they can answer... (Water Contemplates)
Acheron - A place of
earth, fire, water, but no air. A chill waste without obvious life. While there is a sky, there is no wind and sound carries strangely. A shout is barely heard at 50 ft, but have someone's gaze and they can hear you whisper. Nothing flies, seemingly nothing can travel upwards more than 30 ft. above a surface. It is a place of the lost, broken, and forgotten; a realm of exile but also of travel. Many ancient beings are here, discarded gods and banished demons wander about looking for escape. Most any other realm, save Salandron, Vaalbaran, and Carceri, can be reached from here. But, travel quickly before you become the stone under your feet... (Earth Fossilizes)
Asphodel - A place of
air, water, fire, but no earth. A world of wings, light, and drifting realms tucked into spherical tree-like growths. Angelic beings shepherd beings to strange glades to rest, heal, and forget their past lives. Travelers here can potentially find the spirits of the departed before the return to the cycle of reincarnation or move on to the Long Road. Powerful servants and cohorts of the Patrons can also be found here. But, you have to evade their guardians. (Air Travels)
Anakarum - A realm where nature is "larger than life". Storms rage, trees tower, and mountains scrape the sky. Everything grows 5-10x the size, jewels the size of your fist glimmer from canyon walls, and you wake up feeling more alive than ever before. Giants, behemoths, leviathans, and zazzan dwell here, and you could find yourself a pet in a gilded cage if not simply consumed. (Bodies Act)
Lyonesse - The realm of the fae, and the Veil of Dreams. This is a world that most people travel to, although they seldom remember it. The Veil shrouds the mortal worlds preventing easy access to primal creatures such as ifrit, demons, and eidolons. The Veil is plastic to mortal minds, but as primals do not dream what happens to them in the Veil
happens. A child could destroy a balrog with a simple fearful "
go away!", and it does so, forever. (Dreams Reveal)
Rhoder - A twilight place of stars, moons, but no sun. People live amid startides that blow silvery winds through the pearlescent leaved trees and gather moonstone from where it has fallen from the sky. But they always hide from
Sol Adligatus, the hate of the dead but shackled sun that creeps across the sky. (Thought Expresses)
Carceri - The realm of the forsaken. Only accessable from Acheron, here the Fallen One guards the Iron Sun that seals the rift to the Outside of Creation. Serving the mortals that It once desired to rule, the Fallen One gazes down on the prison where the demons are trapped. Only such a consummate strategist such as It can anticipate the actions of the things from Outside. It rules from the drifting, shattered landmasses that orbit the dark fire of the Iron Sun. (Hate Imprisons)
All realms save for Salandron and Vaalbaran can be travelled to without special protections. Acheron and Lyonesse are often accessed as it allows for fast travel through other worlds. It is far more likely to encounter a denizen in Lyonesse than Acheron, but the latter is usually drastically more dangerous.
*There are at least four different lists that I'm aware of, and they're all different. The similarities are that they all have Asgard, Midgard, Jotenheim, Muspelheim, and Niflheim.