Unlike the High Umbra, the Middle Umbra is not organized hierarchically. Instead, it is divided into a series of discrete realms of physical reality divided by gulfs of relative emptiness and pockets of spiritual activity. Roads between these realms vary considerably (moon paths and trods being two examples). Realms in the Middle Umbra usually have their own Gauntlet and many are apparently infinite in their own private scope. While many realms in the Middle Umbra resemble the abstract realms of the High Umbra, the important distinction is that the realms of the Middle Umbra exist independently from the consciousness of humanity, while the High Umbra does not. The Middle Umbra is also notable for the influence of the Triat and the presence of entire hierarchies of spirits associated with them. While many realms are not controlled by one of the Triat, most realms have also been touched by one or more of them.
Realms found within the Middle Umbra include:
- Abyss (also called the Chasm)
- Aetherial Realm/Reaches
- Battleground (also called the Realm of Fighting Spirits)
- CyberRealm (also called Dystopia)
- Erebus
- Flux
- Hy-Brasil (also called the Arcadia Gateway)
- Legendary Realm
- Mountains of Heaven
- Pangaea
- Scar
- Summer Country (also called the Gardens of the First Age)
- Tiger Lands
- Umi (also called the Dragon Kingdom of the Sea)
- Wasteland
- Wolfhome