8 Ways to do Elemental Planes

[1] Pure Elements

The plane is literally just an endless amount of whatever element it encompasses. Opening a portal to the elemental plane of water would eventually flood the world; it just dumps nothing but pure water. Same for the plane of fire, which is some platonic ideal of fire that burns endlessly without fuel, or the plane of Earth which could just be an entire endless universe of solid stone that can be broken down into stones, grit, sand, soil, etc. This may require additional elemental planes for cross elements or sub elements, like the elemental plane of air and the elemental plane of lightning, OR the elemental planes are what the “pure” element is like and all variations are just things that can occur in the real world. Ie; Ice is just water that gets too cold, not a real element. In this version, Elementals may just be animated forms of elements given life by magic, not a native thing.

[2] Pure Elements+

In this version, elemental planes each are purely of their element and a few sub types. The elemental plane of air is filled with clouds, fog, winds, lightning storms, vapor and so on but has no living beings or complexity within. The elemental plane of Earth may be filled with stones, salt, gravel, soil, as well as metals and ores- with precious metals rarely strewn between or each given its own endless but somehow separate part of the plane if you wanted magicians opening portals to have potentially endless access to gold and diamonds, or maybe these just don't exist in the elemental realm. In this version the elemental planes may have some kind of structure- such as the plane of water having a endless snowy field on top of an endless glacier on top of an endless ocean, on top of an endless lake of brackish water, and abyssal water beneath that and so on- elementals could be native here, living among these types of various elements in an abstract existence living beings barely understanding.

[3] Lived-In Elements

As the Pure Elemental Plane or Pure Elemental Plane+ but with creatures that live among the layers. Humongous leviathans may live in the plane of water, or pheonixes may forever fly through the elemental plane of fire- these could be right there with the elementals or once again separated somehow, the various “tiers” of creatures. The ecosystem is based off of basic and advanced elements and elementals- their environments are foreign but the creatures make sense, or somehow change into something more sensible when they come here.

[4] Abstract Elements

The Elemental Planes may be filled with each element and sub elements, but may also have several “supernatural” elements that don't exist in the physical realms. Things like solid and liquid fires, forever exploding materials, burning air vapor and so on for the elemental plane of fire. The Plane of Earth may have a constantly shaking earthquake element zone, along with breathable soil and mulching stones with magic innate within them and so on. It's difficult for mortals to understand, as it is an inherently alien and foreign place to them. Creatures of this plane may be as Lived-In Elements or may be various tiers and types of elementals; different classes or even kingdoms of these beings could exist in such an abstract realm.

[5] Sensible Planes

In this example; the elemental planes may be much more similar to the normal or real world. Instead, all the planes are filled with enviorments, creatures, and even cultures or beings that simple live around the elements in question. For example, the elemental plane of fire could just be a very hot and barren land like a desert with no rain or snow; these cultures could be filled with elemental spirits or even human-like races that live here and are used to it. The elemental plane of water could just be filled with many oceans and rivers and swamps; the air is thick with mist but beings still live here similar to the prime material world. Additionally, these places may be able to be visited much easier then all the other examples on this list, but the planes could also get much more “extreme” the further they travel, such as in Elemental Directions.

[6] Elemental Directions

The Elemental Planes may actually just be a physical place in the world; the farther out out of the barren deserts you go the hotter it gets until eventually it just becomes nothing but burning sand, and from there on it becomes even worse and an even brighter inferno and so on. I wrote about this concept more here.

[7] Afterlife but for Elements

Similar to the D&D conceptualization of Hell, the Elemental Planes are ordered similarly. There may be elemental lords and lesser elemental ruling over specific types of elements. There may be layers with more intense versions of the elements; up to and including abstract and unreal elements from the Abstract Elements concept. Summoning an elemental is similar to calling forth a demon, just from a non-evil plane, just an elemental one instead.

[8] Not Elemental Planes at all

The Elemental Planes aren't really Elemental planes; they are simply alternate dimensions that people draw from. The Elemental Plane of Air may actually just be a realm called “Zephyr”, filled with flying airship pirates, huge birds, and magical storms. They see the Earth as a strange dimension like any other; its rules and creatures are just as alien and dangerous as you see their simple flying creatures are! With this rule, you can also free dimensions entirely, making every alternate realm or otherspace a different and strange place instead of neatly ordered.