Astral Plane

 "It is the space between everything.   It is the road that goes everywhere. 

 It is where you are when you aren't anywhere else." 

The Astral could be reached from almost any point in a Prime Material plane or first layer of any Outer plane by spell, ability or magical item. It was described as a barren place of other-dimensional nothingness extending in all directions. What little solid substance that floated in the bright, grey void was typically chunks of matter broken off from their original plane. The Astral had no gravity but objects did retain their mass so you could throw small items or push off from large objects to move in the weightless environment.

Time in the Astral flowed at the same rate on a Prime Material plane but the effects of time were slowed almost to a stop―a thousand years in the Astral plane felt like only a day to the traveler. Creatures did not go hungry or age while in the Astral plane. For that reason, its mortal inhabitants needed to return to the Material Plane in order to have children or to reach adulthood.

Entering the Astral plane could be accomplished in one of two ways: projecting your astral form into the plane via the astral projection spell, or by physically entering the plane. Astral projection was the safest way to travel but still involved risk because you left your physical body behind on the traveler's plane of origin. The astral body would be accompanied by the astral forms of any items and clothing that were magical or radiated a magic aura. While projecting, your astral self was connected to your physical body by a silver cord that stretched out behind you for about 10 feet and then became invisible and intangible.

Very few things could sever this silver cord: a powerful psychic wind, a githyanki sword or the will of the gods. The physical body left behind appeared alive but did not require food, water, or air and did not age. It could be moved and was vulnerable to damage and death. If the traveler's physical body was slain, death followed the projection some minutes later. If the astral self was slain, the traveler then returned to his or her physical body in a coma. Physically entering the Astral plane required a spell such as plane shift and brought the traveler wholly into the Astral with no silver cord to anchor her to her plane of origin.