Sanctum Library: The Astral Sea

The Sanctum

Inside Alustriel's Sanctum library, the group uncover the following information on the Astral Sea:

The Astral Sea: A Planar Treatise from a Baldur's Gate Perspective
By Master Borin Stonehand, Sage of the Great Library of Baldur's Gate

The Astral Sea, frequently referred to simply as the Astral Plane, represents a fundamental and enigmatic dimension within the greater cosmology, serving as the primary conduit for interplanar transit. From the perspective of Baldur's Gate, its existence is crucial for understanding the flow of magic and the nature of extraplanar incursions that occasionally touch our very shores. It is best conceptualised as an immense, silvery expanse, a boundless ocean of pure thought and spiritual essence, where the conventional strictures of space and time are rendered meaningless.

The Purpose and Genesis of the Astral Sea

The very existence of the Astral Sea is a subject of profound debate among planar scholars, yet its purpose is unequivocally clear: it serves as the essential interstitial tissue of the multiverse, the medium through which all other planes are interconnected. Without this vast, silvery ocean, direct transit between the Material Plane and the myriad Outer Planes would be an impossibility, or at best, a perilous and unpredictable endeavour. It acts as a cosmic buffer, a neutral ground where the conflicting energies of creation and destruction, law and chaos, good and evil, can meet and dissipate without tearing the fabric of reality asunder.

Some theories posit that the Astral Sea is not a created plane but rather a primordial void, the raw space that remained when the first planes coalesced, a canvas upon which the very thoughts and desires of powerful entities and nascent deities have perpetually imprinted themselves. Others suggest it is a deliberate construct, perhaps the work of an ancient, forgotten cosmic architect, designed specifically to facilitate the orderly (or at least, manageable) flow of planar energies and the movement of souls and travellers. Regardless of its true genesis, its function as the grand nexus of the cosmos, allowing for the astral projection of minds and the passage of spelljamming vessels, is undeniable and paramount to the continued interaction of the planes.

Fundamental Properties

A most peculiar characteristic of the Astral Sea is its complete divorce from temporal progression; within its confines, creatures experience no aging, nor do they suffer the degradations of hunger or thirst. This unique property renders it an invaluable medium for protracted journeys, though prolonged exposure can induce a profound sense of temporal disassociation.

Unlike the Material Plane or even many Outer Planes, the Astral Sea possesses no fixed spatial coordinates or discernible geographical landmarks. Locomotion is achieved purely through the exertion of will and focused intent, allowing one to traverse what would be considered immense distances in an instant, or conversely, remain in a state of static drift for what, in other planes, would be epochs, all contingent upon the traveller's mental fortitude and purpose.

The plane's visual manifestation is predominantly an argent, shimmering expanse, often likened to a vast, liquid silver ocean, punctuated by infrequent chromatic streaks reminiscent of nebulae. These are believed to be residual emanations of potent psychic energies, the echoes of powerful entities, or perhaps the distant, filtered light of the planes it connects.

Its paramount function is to facilitate passage between the Material Plane (including our own Toril) and the myriad Outer Planes, such as the infernal layers of the Nine Hells, the chaotic depths of the Abyss, or the celestial heights of Mount Celestia. This transit is typically achieved via "colour pools," shimmering, disc-like portals whose specific coloration denotes their destination.

Despite its apparent emptiness, the Astral Sea is not entirely devoid of physical presence; the petrified remains of deceased deities, the spectral echoes of forgotten cities, and even fragmented demiplanes are known to drift within its expanse, often remnants of cataclysmic events or the lingering effects of powerful arcane manifestations from other realities.

The Astral Sea

Wildspace: The Spheres Beyond Toril and Spelljamming Vessels

While the Astral Sea connects the various planes, it is important for the scholar of Baldur's Gate to understand its relationship to Wildspace. Wildspace refers to the void that surrounds individual planetary systems, a distinct pocket of vacuum and celestial bodies contained within a larger, often invisible, sphere of crystal. Our own Toril, with its moons and sun, exists within such a crystal sphere, and beyond its boundary lies the boundless Astral Sea.

These Wildspace regions are essentially miniature universes, each with its own sun, planets, asteroids, and sometimes even unique celestial phenomena. Travel within a Wildspace system is typically accomplished by spelljamming vessels, magical ships capable of sailing through the vacuum of space. The air and gravity within these ships are sustained by magical means, allowing for conventional life to exist within the otherwise hostile environment.

Spelljamming vessels themselves are marvels of arcane engineering, their designs remarkably diverse, often reflecting the aesthetics or even the biological forms of their creators. One might encounter sleek, ceramic Star Moths favoured by the astral elves, robust Space Galleons reminiscent of terrestrial sailing ships, or the fearsome, tentacled Nautiloids of the mind flayers. Other notable designs include the heavily armed Bombards of the Giff, the nimble Damselfly ships, the versatile Flying Fish vessels, the ramming Hammerhead ships, and the grappling Lamprey ships. Regardless of their unique appearance, these vessels share a common core: the Spelljamming Helm.

The Spelljamming Helm is a magical artifact, typically appearing as a chair or throne, that serves as the ship's primary means of propulsion and control. A spellcaster must attune to the helm and sit upon it, channelling their magical energy to power the vessel. This connection allows the pilot to steer the ship by thought, and even perceive events on and around the vessel as if they were physically present at any point. The helm also generates a self-contained, breathable air envelope around the ship, typically extending 180 feet in all directions, and establishes a localised gravity plane, allowing crew members to walk on the deck and even the underside of the hull as if on solid ground.

Travel through Wildspace and into the Astral Sea is a seamless transition for a spelljamming vessel. As a ship travels far enough from a planetary body within its crystal sphere, the vibrant colours of Wildspace gradually fade into the silvery haze of the Astral Sea. While in Wildspace, ships can achieve incredible speeds, often reaching 100 million miles in 24 hours in open void, though they slow considerably when in proximity to other large objects.

Once in the Astral Sea, the need for air and gravity diminishes due to the plane's inherent properties, but the spelljamming helm maintains these conditions for the comfort and safety of the crew, particularly for when the vessel eventually transitions back into a Wildspace system. Repair and maintenance of these vessels are crucial, as they take damage like any other object, often requiring the application of magical mending or more extensive, costly repairs. Understanding Wildspace and the mechanics of spelljamming is thus crucial for comprehending the full scope of planar travel, as it represents the immediate interstellar frontier accessible from our home world before the true depths of the Astral Sea are encountered.

A Spelljamming Vessel sails the Astral Sea

The Rock of Bral: A Nexus in Wildspace

Among the myriad celestial bodies and drifting detritus of Wildspace, few hold as much significance for planar travellers and merchants as the Rock of Bral. This sprawling asteroid, once merely a chunk of rock, has been transformed over centuries into a bustling, lawless, yet surprisingly organised port of call and trading hub. It floats freely within the Realmspace crystal sphere, making it a primary destination for spelljamming vessels departing from or arriving at Toril.

The Rock of Bral is a testament to the ingenuity and adaptability of the various races that ply the void. Its surfaces are honeycombed with caves, tunnels, and constructed dwellings, all benefiting from the magical air and gravity generated by numerous spelljamming helms permanently installed within its core or along its major thoroughfares. It is a melting pot of cultures, where giff mercenaries rub shoulders with elven traders, dwarven prospectors, and opportunistic human pirates. While officially a neutral territory, its governance is a complex web of informal agreements, powerful factions, and the ever-present threat of violence. For adventurers from Baldur's Gate, the Rock of Bral offers unparalleled opportunities for trade in exotic goods, recruitment of unique crew members, and access to information about distant worlds and the wider multiverse. It is a place where one can find anything from rare astral charts to illicit magical artifacts, making it an indispensable, albeit dangerous, waypoint for any serious exploration of Wildspace and beyond.

The Rock of Bral

Indigenous and Transient Populace

While not densely populated, the Astral Sea supports a distinct ecology of unique entities and serves as a thoroughfare for various planar travellers. Among its most fearsome inhabitants are the Astral Dreadnoughts, gargantuan and terrifying entities that represent the apex predators of this plane, possessing an inherent immunity to most magical energies and existing solely for consumption. These colossal creatures are a constant peril to any who traverse the silvery void. A formidable race of militant humanoids, the Githyanki, have established permanent enclaves within the Astral Sea; renowned for their martial prowess and potent psionic abilities, they are infamous for their symbiotic relationship with red dragons and their relentless pursuit of mind flayers, often constructing their settlements upon the ossified husks of dead gods. Complementing these are the reclusive and ancient Astral Elves, a subrace that has adapted remarkably to the unique conditions of the Astral Sea, frequently navigating its expanse aboard specialised spelljamming vessels. Beyond these, a diverse array of Planar Wayfarers, including potent arcanists, celestials, fiends, and intrepid adventurers from countless planes, regularly traverse the Astral Sea, typically by means of the astral projection spell or other potent magical devices.

Beyond these more formidable or sentient beings, the Astral Sea is also home to various forms of less understood, often piscine, life. These "astral fish" are not true fish in the biological sense, lacking the need for water or air, but rather creatures that navigate the silvery void with a fluid grace reminiscent of aquatic life. They range from small, shimmering motes of light that might be mistaken for distant stars, to larger, more predatory forms that hunt the psychic energies or smaller creatures drifting through the plane.

The genesis of these astral fish is largely theoretical. Some scholars propose they are manifestations of raw psychic energy given rudimentary form, drawn from the collective thoughts and dreams of creatures across the multiverse. Others suggest they are the lingering echoes of life from planes long since destroyed, their forms adapted to survive in this timeless void. Their purpose, if any beyond mere existence, appears to be tied to the consumption of errant psychic residue or the occasional, unwary traveller. The larger varieties are known to be opportunistic predators, while the smaller, more numerous types seem to drift aimlessly, perhaps acting as a form of cosmic plankton for the plane's more substantial denizens. Their very existence is a testament to the strange and adaptable nature of life within the multiverse, thriving in an environment that would be instantly fatal to most creatures from the Material Plane.

New Races found in the Astral Sea

Notable Features and Phenomenological Observations

The Astral Sea is characterised by several key phenomena that define travel and interaction within its unique environment. The most ubiquitous means of ingress and egress are the Colour Pools, which manifest as shimmering, disc-shaped portals, each distinct hue corresponding to a specific destination plane; careful identification of these colours is paramount for safe passage. Movement within this timeless void is intrinsically linked to the strength of one's thought and will, a concept known as Volitional Propulsion. A resolute mind can achieve rapid transit across vast distances, whereas a wavering will may find itself adrift, moving at a languid pace or even remaining static. While largely characterised by its stillness, the Astral Sea is not entirely static; "Currents" or "winds" of psychic energy, referred to as Psychic Currents, can periodically manifest, subtly influencing the trajectory of travellers and occasionally leading to unforeseen destinations.

A striking feature of the Astral Sea are The Cadavers of Deities, the colossal, petrified remains of defunct divinities that drift through its expanse. These inert forms, often hundreds or even thousands of miles long, appear as vast, silent monuments to forgotten pantheons or divine cataclysms. Their surfaces are often rich in rare minerals, strange flora, and even unique forms of life that have adapted to dwell upon these inert husks. Some scholars theorise that these bodies are the remnants of gods who lost all their worshippers, or perhaps were slain by other deities in ancient, cosmic wars, their divine essence having dissipated into the Astral Sea itself, leaving only their petrified forms behind. These colossal cadavers frequently serve as mobile strongholds for the Githyanki, who carve cities into their stony flesh, or as points of profound interest for planar explorers seeking ancient knowledge, forgotten relics, or merely a unique landmark in the otherwise featureless void.

In conclusion, the Astral Sea remains a realm of boundless potential and inherent peril, serving as the essential arterial network of the multiverse, connecting all realities while paradoxically existing in a state of profound detachment from them. Its study is vital for any serious scholar of planar dynamics.

A Dying God in the Astral Sea