Numerous unusual worlds exist parallel to the world of men. Sorcerers can use portals to travel to these realms.

Each world is distinct. The flora, the fauna, the climate, and even the colors of the sun and sky can vary from one to the next. Most are not instantly toxic to humans, though some are harsh enough that prolonged exposure can have serious consequences.

The topography is different for every realm. Some are covered in forests; others, deserts; some are nothing but water broken only occasionally by rocky islands.

Faer

Faer is a world much like our own, but brighter. It is home to all manner of elves, goblins, sprites, giants, and other creatures of folk tales. Some of these creatures are kind and generous, some are mischievous, and some are malevolent. All are alien.

Some Faeries are willing to travel to our world out of curiosity or spite. Others prefer to lure humans into their realm for various purposes.

Idimmu

Idimmu is a hot and barren realm. A dim red sun engulfs a third of the dark blue sky. The air is dry and thick. The rocky deserts are inhabited by some of the most savage creatures in existence: brutal demons, cruel devils, immense dragons, and hordes of strange, vicious beasts.

Sentient natives often wish to leave their infernal prison. These creatures have been known to make deals with sorcerers in exchange for their freedom.

Uggae

Uggae is a black void at the edge of creation. Cold, slimy things slither in wet darkness lit only by faint stars. The creatures of Uggae, called "horrors" by sages, are powerful and alien beyond comprehension. There is no communicating with such things - they take no more notice of humans than humans do of insects.

Only fools or madmen attempt to bring horrors to their own worlds. Fortunately for humanity, this is an arduous task. Horrors are so immense that it is almost impossible to create a portal large enough to allow more than a fraction of one to pass. Even this can be grave - a single appendage of a horror can wreak vast destruction over a significant area.

Though rare, there are lunatic cults that dedicate their lives to bringing Horrors into the world.

The Spirit World

The "spirit world" is not a separate realm, like Idimmu or Faer, but a metaphor for that subset of the physical world that is hidden from the perceptions of normal persons. The restless ghosts of dead beings travel within our world alongside more exotic ethereal entities.

Some spirits can manifest themselves in the physical world to communicate with the living. Others cannot be contacted without the aid of mysticism.

Spirits are not constrained by walls or borders, so can often obtain information unavailable to the living. Getting this information from them can be daunting, however: aside from the difficulty in communication, there is no reliable way to determine the identity or honesty of any particular spirit. One must take them at their word.

Furthermore, it is difficult for the unaware to tell the difference between the whispers of the dead and their own thoughts.

There are other worlds than these. The Adversary should feel free to be creative.