Dreamlands

Created and sustained by the collective dreams of sleeping mortals, the Dreamlands, also called the Dimension of Dreams, overlays the Ethereal Plane. A creature that dreams interacts directly with it wherever its physical body happens to be, casting itself into the plane in an idealised avatar known as a lucid body. Individual dreamscapes are immune to outside entry by standard magic such as interplanar teleport, and reaching one requires obscure and more specialised spells.

The dreamers of each mortal world generate a cluster of dreamscapes, like drifting bubbles atop a deeper ocean of permanent dreams formed from the collective mass of slumbering desires, the dreams of especially powerful dreamers, and the dreams of ancient and obscure entities. Most dreamscapes are safe. Travelers in the deep, permanent Dreamlands face living animate dreams, the predation of hags out of the Ethereal Plane, and stranger beings spawned within the core itself. Some scholars hold that nightmares occupy a distinct region of their own.