The astral plane is vast beyond comprehension, it is a realm of thoughts and dreams, where the idle wishes of its residents could become reality. The astral plane permeates the entirety of Orizon’s outer planar geography, connecting the material with the gods and demons.
It is a great silvery sea, the same above and below, with swirling wisps of white and gray streaking among motes of light like distant stars. Most of the Astral Sea is a vast, empty expanse. Visitors occasionally stumble upon the petrified corpse of a dead god or other chunks of rock drifting forever in the silvery void.
Much more commonplace are "color pools", magical pools of colored light that flicker like radiant, spinning coins.
Creatures on the Astral Plane don’t age or suffer from hunger or thirst.
Traveling through the Astral Plane by means of the astral projection spell involves projecting one’s consciousness there, usually in search of a gateway to an Outer Plane to visit. Since the Outer Planes are as many spiritual states of being as they are physical places, this allows an individual to manifest in an Outer Plane as if he or she had physically traveled there, but as in a dream. An individual’s death-either in the Astral Plane or on the destination plane-causes no actual harm. Only the severing of a character’s silver cord while on the Astral Plane (or the death of his or her helpless physical body on the Material Plane) can result in the character’s true death. Thus, high-level characters sometimes travel to the Outer Planes by way of astral projection rather than seek out a portal or use a more direct spell.
Only a few things can sever a traveler’s silver cord, the most common being a psychic wind (described below). An individual who travels bodily to the Astral Plane (by means of the plane shift spell or one of the odd portals that lead directly there) has no silver cord.
A traveler in the Astral Plane can move by simply thinking about moving, but distance has little meaning. In combat, a creature’s walking speed (in feet) is equal to 3 x its Intelligence score. The smarter a creature is, the easier it can control its movement by an act of will.
Dreamers
Some on Orizon are born with a connection to the astral plane. Every night, when they go to sleep, they visit the astral plane. With training or practice, they may become able to control themselves while they are there, otherwise, they may simply believe that they are dreaming.
Dreamers are valued as seers and oracles for their ability to travel the astral plane and gain those insights. The stronger the dreamer, the clearer they can see within the astral plane, and the clearer the information they can obtain while in there.
Psychic Wind
A psychic wind isn’t a physical wind like that found on the Material Plane, but a storm of thought that batters travelers’ minds rather than their bodies. A psychic wind is made up of lost memories, forgotten ideas, minor musings, and subconscious fears that went astray in the Astral Plane and conglomerated into this powerful force.
A psychic wind is first sensed as a rapid darkening of the silver-gray sky. After a few rounds, the area becomes as dark as a moonless night. As the sky darkens, the traveler feels buffeting and shaking, as if the plane itself was rebelling against the storm. As quickly as it comes, the psychic wind passes, and the sky returns to normal in a few rounds.
The psychic wind has two kinds of effects: a location effect and a mental effect. A group of travelers journeying together suffers the same location effect. Each traveler affected by the wind must also make a DC 15 Intelligence saving throw. On a failed save, the traveler suffers the mental effect as well. Roll a d20 twice and consult the Psychic Wind Effects table to determine the location and mental effects.
d20 Psychic Wind Location Effect 1-8 Diverted; add 1d6 hours to travel time 9-12 Blown off course; add 3d10 hours to travel time 13-16 Lost; at the end of the travel time, arrive at a location other than the intended destination 17-20 Sent through color pool to a random plane on Orizon
d20 Psychic Wind Mental Effect 1-8 Stunned for 1 minute; you can repeat the saving throw at the end of each of your turns to end the effect on yourself 9-10 Short-term madness (see chapter 8 in the DMG) 11-12 11 (2d10) psychic damage 13-16 22 (4d10) psychic damage 17-18 Long-term madness (see chapter 8 in the DMG) 19-20 Unconscious for 5 (1d10) minutes; the effect on you ends if you take damage or if another creature uses an action to shake you awake