The astral plane is a realm of abstraction, free from the confines of flesh and gravity. The astral blurs the lines between person, place, and object: two travelers might find shelter in a shared memory, a lone traveler may have a dialog (or combat) with the internal representation of an old friend, or embarrassing secrets might conspire to ambush a seasoned adventuring party. In the astral, the abstract is at least as real as the concrete.

Most astral beings interact directly with other abstractions, exerting pressure on the planes in largely-inscrutable and incomprehensible ways. Their machinations occasionally attract the attention of gods, but for the most part these astral mechanisms appear to cancel each other out. With an infinite abundance of ideas acting in an infinite plane, the astral is a realm of much drama, but little discernible impact on the planes at large.

The astral is dangerous to mortal minds because they are so full of half-regarded thoughts. The untrained mind quickly spawns and becomes lost in a muddle of astral geography. Accidental travelers who arrive in projected form experience this mire as a psychedelic trip until the projection fades. Travelers in the flesh, however, have no such safety mechanism, and can linger in the mire until they expire… or until something fishes them out. Hence most astral travelers pass through under cover of powerful spells, or project briefly via drugs or magic. The astral plane rarely sees successful long-term visitors.

Savvy travelers find a wealth of information and insight at their disposal in the astral plane. Sages can literally explore concepts, converse with a god’s mythos, wrestle with ethical dilemmas, exorcise inner demons, and ferret out secret lore from the very structure of the cosmos. Since thought itself is the fabric of the astral plane, anything is possible — both its most alluring promise and its most dreadful curse. Even a seasoned astral visitor is at the mercy of stray thoughts, suppressed emotions, and self-doubt.

Sages often describe the astral plane as a vast void punctuated with shimmering rainbows and geometric shapes not because the plane is so sparse and spare, but because their mental discipline gives them a safe, mostly-empty place to navigate. Those that do not master themselves cannot survive long on an astral journey without powerful magic or powerful benefactors.

Buommans, githyanki, and githzerai are the only peoples known to have migrated from the material to the astral plane. In all three cases, the cultures survived because of great internal discipline. For buommans and githzerai, meditative practice became the foundation of their society. The githyanki, on the other hand, learned to “ride the wave” of their turbulent thoughts, persevering through sheer ferocity. While as a civilization the githyanki have an appalling mortality rate, their technique presents a way for chaotic-minded individuals to survive in the astral plane.

Per the SRD, the astral plane has the following traits:

• Subjective directional gravity. Characters are weightless unless through force of will (and a DC 16 Wisdom check) they designate a direction in which to fall “down.” Failing the Wisdom check one round grants a +6 bonus to the next check. Characters fall 150 feet the first round, and 300 feet each subsequent round.
• Timeless. Age, hunger, thirst, poison, and natural healing don’t function in the Astral Plane, though they resume functioning when the traveler leaves the Astral Plane. Unlike some timeless planes, they do not accrue retroactively upon leaving.
• Mildly neutral-aligned.
• Enhanced magic. All spells and spell-like abilities used within the astral plane may be employed as if they were improved by the Quicken Spell feat. Already quickened spells and spell-like abilities are unaffected, as are spells from magic items. Spells so quickened are still prepared and cast at their unmodified level. As with the Quicken Spell feat, only one quickened spell can be cast per round.

Travel in the Astral

While travelers can navigate the astral reaches by “falling” from place to place, they can also navigate by intellectual exercise. Just as poorly-governed minds can be overwhelmed by stray thoughts and lost in a maze of their own making, enterprising travelers can focus on semantic connections to lead from one scene to the next.

Semantic navigation requires skill checks (Knowledge (lucid dreaming), Knowledge (Dream), or Knowledge (region: Astral)) to “invent” a series of connections. The DC of these checks depends on how obscure the destination is. A Will save (at the same DC) is required to marshal the navigator’s thoughts enough to carry through the leap of logic. The GM may require multiple Will saves to complete the journey. Any interruptions (like combat) require a new course to be plotted.

Travelers are strongly advised to use multiple means of staying together. Since straying thoughts means straying geography in the astral plane, travelers can quickly end up out of sight on an infinite and ever-changing plane. This is not a good thing. If separated from the rest of the party, a traveler’s best hope is typically to concentrate on thoughts of other part members (or a pre-determined shared mental image) and plot a semantic navigation route. Whether that leads the traveler to actual travel companions or mere phantasms is largely luck of the draw.

As for leaving, where travelers go from the astral plane depends on how they entered. Those who projected in, usually dreamers or the drugged, can access the Dream and the ether, perhaps plumbing the depths of the Shadowlands if they really want to. Those who brought their bodies can get just about anywhere from the great semantic web of the astral plane.

To travel to other planes, voyagers simply employ semantic navigation to move to a space that strongly embodies their destination. Once they have gone deep enough into thoughts of the destination, they will find a portal. For well-trained sages, this often takes the shape of a pool of light, but the form depends entirely on the traveler. Projected travelers cannot use portals that go to places inaccessible to them, but just because a portal works doesn’t mean it is the right one.

The boundaries between the astral, ethereal, and Dreaming realms are more ambiguous than other boundaries, and travelers may cross into the ether or the Dream without even noticing the portal. Thankfully, these realms are porous in both directions. If thoughts of foggy places land you in the ether, for example, chances are good that you can find your way back if you act quickly.