Elemental Plane of Earth

Earth is a fundamental component of the multiverse and perhaps the most visible to most inhabitants of the Material Planes. Continents, islands, mountains, hills – these are all concrete examples of this ubiquitous element across the realms, and it shows up in all of the other Inner Planes as well in one form or another. And the root for all that rock and dirt is the Plane of Earth.
Much of this Elemental Plane of Earth is solid mass making it difficult for non-native creatures to move around or even breathe. However, limitless tunnels, passages, and caves wind their way through the stony realm, the result of both incursions from other Inner Planes and determined digging efforts by the native creatures. The dao, genies of the earth, are the cruelest of slave drivers upon the Plane and constantly seek out veins of rich minerals and ore to adorn their fabulous abodes.
Getting lost in the Plane of Earth is perhaps the greatest threat to travellers beyond a collapsing tunnel or marauding beast as there is no clear indication of any cardinal direction. Tunnels wind up and down, cross between each other, and cut into massive caves with no discernable pattern or thought. For travellers willing to risk the journey, however, great treasures and wonders can be found, whether it’s the prize opal Koh Nur in the centre of the dao’s Sevenfold Mazework or searching the chaotic Tunnels of Madness for the Heart of All Mountains or trying to escape the infamous Salt Dungeons of the Great Khan.

Portals to the Plane

The dao do their best to control or shut down unwanted portals to the Plane of Earth, so the number of known gates to the plane is relatively small. The City of Glass on the Plane of Water contains a known gate, along with the City of Brass on the Plane of Fire. The dao occasionally have dealings with the fiends of the Lower Planes with spontaneous portals forming occasionally.
In the Material Plane, natural gates and portals have been known to appear in the deepest mines dug by dwarves. Many dwarven strongholds consider themselves the first line of defence against incursions from the Plane of Earth, whether it be by natural monsters or planned invasions by the dao. For their own interests, the dao consider Dwarf slaves the best the Material Plane can provide (followed by gnomes) and actively raid dwarven outposts and strongholds to replenish their slave pens.
Some deeper dungeons in the Material Plane have been known to contain gates to the Plane of Earth as well, whether stumbled upon accidentally or deliberately opened by wizards and priests eager to use earth elemental creatures as guardians and workers.

Powers of the Plane

The Earthsoul, Lord of Earth and Mountain - Primordial of the Elemental Plane of Earth
The Primordials are entities of raw power that are believed to embody the very planes that exist upon, their powers are said to rival even that of deities. The Primordials are said to be the first entities born of their planes, ageless in nature and bottomless in power. The Earthsoul is said to be a large portion of the Plane itself, being so massive that kingdom and empires formed around its very body. There is no doubt that the Earthsoul is the most powerful entity upon the Plane.
Elemental Lords of Earth
The Elemental Lords of Earth are the princes and princesses of the elementals, owing allegiance to none but themselves and working towards their own ends. These immense beings are comprised of the very stone and earth that makes up the plane. There are at least three elemental lords known – Ogremoch, Entemoch, and Sunnis. The plane is vast, however, and others may still exist, dormant or waiting.
Gargoyle Princes
Gargoyles are a common encounter in the Plane of Earth along with margoyles, their wingless cousins.The most powerful of these native denizens are the Gargoyle Princes, each ruling a princedom in the Plane of Earth carved to their specification. The exact number of Gargoyle Princes is unknown, though at least four are known to exist. Each is thoroughly evil and represents the most ambitious aspects of the ancient gargoyle race
Great Khan of the Dao
In the centre of the Great Dismal Delve sits the Sevenfold Mazework, the largest dao settlement in the multiverse, and in the centre of that (beyond the first five maze layers) rests the palace of the Great Khan known as the Hidden Fulcrum. When a dao ascends to the role of Great Khan he or she forsakes their name in favour of the title, so it is difficult for an outsider to know when the power in the dao khanate shifts.

Denizens of Earth

The Elemental Plane of Earth is home to all manner of creatures, including many from the Material Plane. Among the most populous of the denizens of the Elemental Plane of Earth are the earth elementals, the dao, and gargoyles all of which are natives to the Plane. Creatures originally from the Prime Material Plane are also common, Genasi, gnomes, dwarves, and Goliath being the most populous.