|Mike Schley's map of the Elemental Planes for 5th Edition. Very pretty - ALL LIES|
A convergence of all four elements, with People as the ultimate expression of their confluence. Not a place of harmony, but one of such perpetual roiling imbalance as to create a perfect storm. The spearhead of reality, its potential draws the attention of the gods and its life is the purest expression of such that we can conceive (Editor's Note: grossly short-sighted but ok, sure).
Planets suspended in phlogiston, orbiting stars that extend for light-millenia in all directions. A Universe.
(not mentioned here are other dimensions, such as the plane of Faerie and several of the Hells - these exist on something of a metaphysical Z-axis, while we concern ourselves here chiefly with the X and Y of it all)
Fire, air, earth, water. Not planes at all, but concepts - pure expressions of the four base realities that form the Material.
These are, contrary to the old wisdom, not Places one can Go. They are mathematical and alchemical constants, a sphere of pure existence that binds our universe.
The "Elemental" Planes
If the Material is where all four elements collide, then these are the other places within the Inner Planes in which they make contact. Pairs of concepts butting up against one another to form realities. They are remarkably similar to the Material, even if they lack all the base components.
Within each there exist areas where matter, time and space flow in such a manner to make them habitable to life as we understand it, almost like the planets of the Material realm. When we discuss the Planes, we speak of these areas specifically.
The Plane of Ash (Fire & Air)
A place of wild passion, the heat and smoke making the air unbreathable. Perhaps the least habitable of the planes - although helldozers, by complete happenstance, are ideal for traversing it.
Colour Palette: Pitch black, hellish red, vibrant orange, smoky grey.
The Wildlife: Sky-things, like fish and dragonflies. Beautiful and in a constant dance.
The Locals: Ethereal wisp-people of wild, joyful energy. Try to resist their calls to come outside.
Why Are There No Maps: Pure whim and passion without the stabilising natures of water and earth make for a directionless mess. There is no up or down here, only a whirling storm.
What Might Bring You Here: It's been suggested as less gruesome route for hellholes. Some wizards are showing up to places covered in ash rather than blood now - very hip.
The Plane of Ice (Air & Water)
A vast cold sea, almost entirely frozen. Nearly unerringly calm, its nights and days are each ages long.
Colour Palette: Blank white, cloud grey, pale blue.
The Wildlife: Transparent fish, blubbery mammals. A few slow leviathans, some city-like in scope.
The Locals: Of the blubbery, mammalian variety. Diminutive, stoic but welcoming and wistful, changing with their world while holding true to their values of community and peace. They have an almost spiritual bent, despite the lack of gods tending to their realm.
Why Are There No Maps: Floes drift, icebergs crash and change. What was considered a continent sunders overnight with a cracking sound that shakes the sky and leaves a new crevasse.
What Might Bring You Here: The Great Hunt for a legendary and gigantic beast by day, or supposed visions of cosmological truth in the lights that pass over the night sky.
The Plane of Ooze (Water & Earth)
A wet marsh of life-stuff. Organs and membranes and plant matter without drive or purpose, stagnant and resolved to do little but grow slowly and die.
Colour Palette: Jungle green, bile yellow, mud brown, gore red.
The Wildlife: Resembling that of the Material realm, but in fits and starts. Like errors of creation, stupid and pointless. So many plants, bugs, things like bacteria.
The Locals: Varied tribes of meat-plant-folk, each adapted by the cosmic joke equivalent of evolutionary luck to be driven to one thing: eat, kill, fuck, build, destroy, etc. The most agreeable are the placid majority who simply exist to exist.
Why Are There No Maps: Too complex. One would need to produce anatomical diagrams-within-diagrams in place of maps or charts on a 1:1 scale to be comprehensive enough to prove useful.
What Might Bring You Here: If a particular part of a plant or animal is needed for some reason, chances are the equivalent has been spawned by sheer randomness within this primordial soup. The locals understand living matter at its basest level and can guide you.
The Plane of Magma (Earth & Fire)
Rock and molten rock. Terrible, unbearable heat. Spires, cliffs, valleys, the only light from below.
Colour Palette: Soot black and stone brown, sun yellow and shining blood red.
The Wildlife: Of stone. Biology like engines or clockwork. Violent, hardy, quick: pick two.
The Locals: It would be a mistake to call them golems, for they are self-driven. Large, loud, passionate but unchanging. Tribal tradition, feats of bravery and strength are honoured.
Why Are There No Maps: That's just not how things are done. The only thing you need consult for direction is your own heart and the will of the elders, brother!
What Might Bring You Here: These are staunch and fierce allies to have, if allies you can make of them. Plus, enormous crystals like nowhere else are buried deep in the rare colder caves, a source of energy as yet unharnessed.
The Plane of Steam (Fire & Water)
Humid. The air endlessly thick with vapour to the point of opacity in places. Dim orange light from a hypothetical sun-like source. Evaporating pools and geysers.
Colour Palette: Coral and dull orange, mist grey, stagnant green-blue, more mist grey.
The Wildlife: Salamanders. Olms, wetfish with vestigial limbs. Macaques and balloon-beasts. Lichens and algae.
The Locals: Attractive, with an affinity for gadgets and tools - technology here is made of stone and crystal and light, rubbery worksuits made of lichen fibres. Wanderlust is common, and all are nomads or explorers.
Why Are There No Maps: They're working on it! Load a geode disc into a projector and take a look at what this explorer's got so far - a half-done map drawn in light, beamed onto the vapour in the air.
What Might Bring You Here: These are an adventuring sort - planestrotters would be in good company. Join them on an excursion, and who knows what loot may be found?
The Plane of Lightning (Earth & Air)
Like an asteroid belt in a storm cloud. Always in flux. These elements cannot find balance - welcome to the crossfire.
Colour Palette: Storm black, lightning white.
The Wildlife: Small and wary, or hardy beasts of burden. Not much of a food chain.
The Locals: Deeply mysterious. They ride the storm.
Why Are There No Maps: Yeah, good luck with that.
What Might Bring You Here: There is a strange beauty to the ensuing battle. The locals have much to teach, if you have the time and skill to learn, and the wit and luck to survive.
Beyond the inner, the Elements do not govern existence. Here dwell unknowable things: aberrations, old ones, gods.
All existence is bound in the Astral Sea, but this far out that is all that remains. This is not something a mortal mind can fully grasp. It is the stuff we dream in, the plane of the soul. A phlogiston of the ethereal, a crossing-place, a dark matter. Some call it the fifth element, quintessence, and claim it to be the birthplace of magic itself.
Better to focus on that which we can reach, for now.