Shadowfell

The Plane of Shadow, or Shadow Plane, is an empty plane of darkness where shadows are cast without any source of light. This Plane connects to other planes not only through portals but also through darkness; this is especially true on the Material Plane, where a monster or mage might use the shadows as a form of transportation. It has also been speculated that the Shadow Plane connects many different cosmologies, thus making it possible for a planeswalker to travel between them.

Description
The Plane of Shadow is a dimly lit dimension that is both coterminous to and coexistent with the Material Plane. It overlaps the Material Plane much as the Ethereal Plane does, so a planar traveler can use the Plane of Shadow to cover great distances quickly. It is also coterminous to other planes. With the right spell, a character can use the Plane of Shadow to visit other realities.

The Plane of Shadow is a world of black and white; color itself has been bleached from the environment. It otherwise appears similar to the Material Plane.

Traits

 * Mildly neutral-aligned. 
 * Magically morphic. Parts of the Plane of Shadow continually flow onto other planes; as a result, creating a precise map of the plane is next to impossible, despite the presence of landmarks.
 * Enhanced magic. Spells with the shadow descriptor are enhanced on the Plane of Shadow. Such spells are cast as though they were prepared with the Maximize Spell feat, though they don’t require the higher spell slots. Certain spells modify the base material of the Plane of Shadow. The utility and power of these spells within the Plane of Shadow make them particularly useful for explorers and natives alike. Furthermore, specific spells become more powerful on the Plane of Shadow.
 * Impeded magic. Spells that use or generate light or fire may fizzle when cast on the Plane of Shadow. Spells that produce light are less effective in general, because all light sources have their ranges halved on the Plane of Shadow. Despite the dark nature of the Plane of Shadow, spells that produce, use, or manipulate darkness are unaffected by the plane.