Dimension of Dreams
Ruled By: Nightmare (equivalent of a Sorcerer Supreme)
This dimension derives its substance from the dreams of other-dimensional sleepers. If beings every where would stop dreaming, the Dimension of Dreams would cease to exist. Dwelling in the Nightmare World, an area within the Dimension of Dreams, Nightmare can see all within his dimension and in the dreams of all other beings, though he must select where he is looking. In his own surreal domain, its landscape littered with remnants of the human imagination, Nightmare is nearly invincible. The very substance of the Dream Dimension is subject to his mental control, altering its form at will. Needless to say, this is a sanity-threatening dimension. Few mortals beside Doctor Strange have dared to confront Nightmare in his own realm.
Yet, despite all this, some chronicled adventures show that intrusions into the Dimension of Dreams are not always noted by Nightmare or, if he did note them, he did not interfere. There could be many reasons for this. He has been forced to act on behalf of other dimensional entities before, possibly certain adventures or activities have been blocked from his sight by a more powerful entity. He sometimes becomes so busy that he cannot afford to turn his attention to matters of lesser importance, such as minor intrusions in his territory.
The dimension itself is a bizarre collection of images and substances, Doctor Strange describes it as "Ever new, ever changing, ever menacing! A kaleidoscope cosmos filled with shifting shapes and colors". Bright light, especially the light of truth or order, as in the wondrous Eye of Agamotto, can disrupt and destroy obstacles, structures, spells, and so on within the dimension. It is a lightly populated dimension, with its main inhabitants being daemons called forth by Nightmare to do his bidding.
Some locations in the dimension are fixed in their form, though still sanity-threatening in their own manner. Doctor Strange once visited a location, distinctly calling it the Dimension of Dreams, where nothing had substance, nothing was material. It was a dimension where the slightest fantasy or dread could instantly become real and console or attack the intruder. No scientific laws existed. Certain magics were extremely powerful, especially those usually hampered by physical laws such as Levitation, Flight, Illusions, etc. This dimension was quite different from the Dream Dimension usually seen in Doctor Strange's adventures with Nightmare. It may be that to control so vast a realm, Nightmare must fix some areas in a set pattern and leave them so that his energy is not constantly being drained.
Another dimension visited by Doctor Strange in his earlier years was called the Realm of Madness, which was completely different from either of these descriptions of the Dimension of Dreams. Yet, in that dimension, one's worst fears took form. Again, this may have been a fixed sector within the Dimension of Dreams.
While the Dimension of Dreams seems vast, it has been called a pocket-dimension and the sense of vastness could simply be yet another of Nightmare's extremely powerful illusions. Voluntary entrance into the Dimension of Dreams can be gained through many means, including sleep caused by the Mists of Morpheus. Involuntary entrance into the Dimension of Dreams happens every time a character falls asleep. While asleep, Nightmare can keep a character's dream form (astral projection) locked up or alter it as he wishes, while the body enters a coma-like state.