This is the prime setting for the concentric circles setting. Fulcrum is comprised of the realms and the wilds spread across five concentric planar spheres.
The old wars
In the old world of the before the world was inhabited by a plethora of races. A huge diversity of aberrant races of which humans where only one. Each race wielded one of the great magics; humanities magic was faith, their gods where physical beings that walked the earth.
The race wars that followed where a series of protracted conflicts to determine the dominion of the world. It destroyed the aberrant species one by one as they where driven to near (or absolute) extinction, exiled from the earth or sealed away. In the end humanity won.
Using the secrets we had won we built a tippyverse (sans golems) and for an age of the world it was good. But the world is cyclic, the powers that sustain it periodically destroy and remake it. Humanity wasn't going to just let this happen; not after sacrificing so much, not after coming so far.
We attempted to use (abuse) true naming to change the nature of humanity, change the fate of the world. It went disastrously right. Eldrich energy flooded into the world through the teleportal networks remaking the world as it was.
• The space time of the landscape was changed into a shifting and twisting taffy (kind of fae wild).
• The gods where pulled apart; the bodies becoming the titans, the mandates becoming the patrons and the minds fragmenting into the dragons.
• The mages of the city became Alfar (insane immortal elves and living demi-gods)
• The surviving peoples of the city became trow (immortal baby trolls) or worse.
• Humanity (and all humans) lost its truname
"lands lie beyond the hills we know"
The wilds have a fully plastic and fluid geography. The horizon acts as a kind of black box, you do not know what may or may not lie beyond it until you are over it. Paradoxically it is unlikely to be the same vista the next time you past (making it near impossible for you to pass the same horizon twice without divine assistance). Add to that the fact that distance and duration are entirely subjective it make mapping literally impossible; wild atlases are a Cartesian nightmare that require both mystic sight and near insanity to appreciate.
The wilds are known as the natural home of the fae as well as a host of exotic flora and fauna not found in more mundane regions. These include a host of mega fauna such as migratory dragons, tarrasque, ettin, collosi and giants.
Wilderlands are the frontiers, they are the middle state between realms and the wilds. More pliant than plastic the wilderlands are difficult to navigate for the uninitiated. One of the more unstable elements of the wilderlands are the ruins relics and monuments of ancient lost realms. These are fully capable of wandering around the landscape or dispersing into the aetherspace for centuries at a time.
Wilderlands are host to isolated villages, small (usually) independent frontier towns as well as more nomadic tribes. Wilderlands are the favored haunts of Kiamera manbeast tribes as well as other beings both more human and less.
The nature of the terrain is affected by the integration of the material planes and collapsing elemental planes. It is this rather than latitude, elevation or airflow that dictate the climate and topography.
Where these planes touch the material they create large amounts of homogenous terrain. Massive forests, deserts, ice caps, mountain ranges, lakes and jungles. At the edges these brake up and spread out over time. The net effect is like pack ice brake up over a multi dimensional overlay
To put it flippantly these are the places where mortals [not fae] live. A realm is geographically pretty stable and home to at least one a nation of people who define themselves as one.
Realms follow the fichers and to a (certain extent) the revers mass ficher principle. The land and nature of a realm is affected by its ruler and the people are shaped by land. For example a realm with an insane king will be subject to greater levels of random or unpredictable events. A hard and harsh realm will shape its people into a hard and hash people.
Naturally occurring realms may be as small as city or as large as a kingdom. Smaller realms do exist but they require divine or magical assistance to be sustained or come into existence at that size. They are normally fringed by a band of wilderland though they may abut other realms or even wilds.
Realms that overextend have difficulties holding themselves together. Realms that collapse often disintegrate into craton linked sub-realms, revert back to wilderland or even to wildspace.
A craton is a shared semi-stable region of three or more realms, often containing a considerable amount of wilderland. One of the defining characteristics of a craton is that its realms define themselves as of that region. Examples of cratons include multi-realm empires such as Xui'Sha or realms with a shared culture such as the lands of the former necrotheistic empire.
A special case is the bi-realm. These are formed of two realms that define themselves in relationship to each other; they usually have an adversarial or antagonistic relationship though symbiotic realms are not uncommon. Bi-realms are highly stable and can endure for millennia. Bi-realms most often emerge from the brake up of larger cratons and form the core of emergent cratons.
This sphere starts at the base of the high clouds and extends upwards from there. It is warmer, thicker, richer and far deeper than atmosphere of that height as any real right to be.
The aethosphere plays host to the tops of the tallest mountains, flying fortresses, levitating mountains, cloudscapes, skyscraping babble towers and Ydrasil trees. Indigenous fauna include air whales, gas floaters, dragons, harpies, furies and other winged humanoids.
By the very nature of the plane advanced magitec is an absolute essential to day to day existence. One would imagine that this would lead to the domination of magoracies; this is not the case. The wizard artificers of this sphere have a tendency to be aligned with one or more of the various competing inter-realm magical industrial combines. Actual leadership of the realms is dominated by the noble clans; be it in duchies, principalities or the oligarchic republics (although having said that these clans have a far higher instance than average of potential sorcerers).
One of the most distinctive phenomena of the aethosphere are the skyships. These craft use magic to levitate and propel them through the air. They are often used by merchants and explorers as well as sky pirates and the various aerial navies. The sight of two fleets of airships hammering seven shaded of snot out of each other is one of the most awe inspiring things in the world and as strong a reminder as can be not to cross mages. Skyships cannot fly bellow the clouds, the ability of the magic keeping them aloft to resist the pull of the earth become progressively weaker the lower they go until it becomes too much and the ship "flounders".
Examples of military magitec include aetherial pulse jets, magistorm Gatlings, ark lightning projectors, S.G.R.S (spirit guided rocket systems), Golem auto loaders and bastion class sky knights. Examples of such tec on the surface are usually limited to badly damaged salvaged from crashed airships or as the "fallout" of aerial warfare.
This is the second sphere of fulcrum. Its residence believe that it is most important of the planes; it does for example have the largest number of realms and 7 out of the top ten largest stable realms, surprisingly it is (by volume) the smallest of the five spheres, it is also the least spherical. It extends only a few hundred meters below ground and scant kilometres above sea level. The terrosphere covers only the large landmasses, inland seas and the oceans within sight of the coast. It is broken up into several large semi-stable continental clusters.
These are the shifting open oceans of fulcrum. It plays host to mysterious storm wracked islands, floating lands, icebergs, horrors from the deep, under sea civilizations (both living and lost) and nations under sail.
This is the sphere of stone. It stats below the frost line and proceeds down past the crush depth to the ferrosphere. It is a wild place of caves, grottos and vaults. It has its parched deserts and its underground rivers, lakes and seas. The vast cavern networks are constantly shifting and are not always mutually accessible, sometime forcing people to the surface to make progress.
N.B This is obviously an underdark stand in with the realms/wilds mechanics built in.
This is the innermost and most hostile sphere of fulcrum. It is composed of an infernal sea of extreme pressure liquid metal encased in solid rock. It is illuminated (if this can be said to be the right word) from its centre by the convergence of the three essential pillars, the flux of positive and negative energy grants the ferrosphere its 36 hour "day"/"night" cycle.
Iffrites are the dominant power of the ferrosphere. Their civilization clings to the deep furrows and ridges of the edge of their world, heavily concentrated on the margins of the stone highlands and the deep basins filled with nickle cobalt oceans or along the antediluvian plains of vast liquid metal river systems.
Like all live in the ferrosphere they posses a silicon based biology with a complex system of metallic ichor and bio plasma. They live in fear of the terrors of the deep core; most particularly the dreaded iron drakes. Aside from certain elemental plains the Iffrite cannot survive outside of the ferrosphere without extensive xenoforming. This transmutation allows them to endure the "extreme cold and low pressure" of the "lesser planes"; this is a permanent exile however as they would never survive the return home.
How would you describe the world of fulcrum?
Take one reasonably standard high fantasy RPG world.
Take sledgehammer to the fabric of time and space
Scatter the bite sized peaces of space time in a broth of elderich fae wilds
Bring to boil and allow to simmer
Season with insane troll logic to taste.
What is a craton anyway?
A craton or tectonic shield is a geological term for a large piece of ancient stable continental crust. Cratons include baltica and siberia. If you can think of a better colloquial name for this don't hesitate to say.