In the world of Portal to Ferrum, the world of Ferrum is one of several overlapping planes that create the universe we play in. 

Ferrum

Ferrum itself is the world of mortals and matter, where the “stuff” of the world exists and where all mortal people are from, and where our adventures largely take place.

The Aether 

The Aether is the space of raw magical energy that exists parallel to Ferrum, but does not overlap it. It is the “world” of pure energy, and is not a “place” in the strictest sense of the word. All magic comes, in some way, from the Aether. 

Argentheum 

Also know as the Silver Forest, Argentheum is the place that overlaps both the Aether and Ferrum, straddling the divide between matter and energy. Its inhabitants, called Argenti, are strange beings with pure magic flowing through their veins. The laws of physics don’t always apply in Argentheum, and situations there can follow a more dream-like logic of symbolism and emotion instead. The border between Ferrum and Argentheum is thin, and mortals may find themselves crossing the border by accident, while Argenti might cross into Ferrum to cause mischief or spirit away unsuspecting mortals. 

Aurum

The Gods reside in Aurum, also known as the Golden City, a plane which intersects Ferrum, Argentheum, and the Aether. The Gods themselves are split into two groups, aligned with either Ferrum or Argentheum, and are called the Ferra (or Ferric Gods) and the Argenta (or Argent Gods) respectively. Mortal souls that pledge themselves to one of the Ferra and are judged to be good in life also end up, eternally rewarded with a seat beside their God. 

Molibum

Set in opposition to Aurum, Molibum is a plane of fire and brimstone where mortals who are pledged to the Ferra and deemed evil end up to be punished for their wickedness. Natives of this plane are named Molibi, and are ruled by the Dread King Galenus, who oversees the souls and torture of all of the Damned. Molibi also are known to travel to Ferrum, where they tempt souls into agreeing to damnation for power, secrets, riches and the like. Molibi are not actually inherently magical on their own, and Molibum does not intersect the Aether: instead, any magic a Molibi can muster is fueled by consuming and permanently destroying the souls of the damned.