The Astral Sea is a Dungeons & Dragons plane in the World Axis cosmology from the the 4th edition of the game. Comparing it to the original Great Wheel is difficult because it serves as both a Transitive Plane, much the original Astral Plane, and as a residence for celestial beings. However, it blends elements of the Outer Planes as a whole into itself, as its various Dominions serve roles analogous to many planes from previous editions. For example, here, one can find not only Arvandor and Celestia, but also Mechanus, Baator and Chernoggar (analogous to the Great Wheel's Acheron).
As its name suggests, the Astral Sea physically manifests itself as a great sea of shimmering starlight and ethereal mists, with other "sub-planes" existing as islands (usually a lot bigger inside than out) floating in the Astral, alongside other various planar detritus. Originally, it wasn't going to look like this, but when the Great Lattice of Heaven was shattered, everything was broken, leaving it in its current oceanic state.
The Astral Sea is covered in brief in the Manual of the Planes, and has its own dedicated sourcebook; The Plane Above: Secrets of the Astral Sea.
Denizens of the Astral Sea
The Astral Sea is full of many different creatures, and in the best D&D tradition most of those probably want to have you for lunch.
Abominations are rare but terrible monsters, living weapons created by the gods and the Primordials alike during the Dawn War but too wild and malevolent to control afterwards. Most are locked up within Carceri, but others roam freely through the Astral Sea.
Angels, needless to say, proliferate here; it is their birthplace, the center of their civilization, and the primary focus of their duties.
Astral Travelers are, obviously, any beings who have reason to be roaming around the Astral. This term covers anything from planar adventurers to divine servitors to Exalted and Outsiders; it just serves as a catch-all for anybody either living a nomad's lifestyle in the Astral Sea or using it as a way to get from place to another.
Bladelings are a nomadic race of razor-skinned humanoid mercenaries, created by the god Bane from his loyal human servants in the Dawn War only for them to turn their backs on him when he abandoned them in favor of the goblinoids. They are particularly common in Sigil, whose "blade and spikes heavy" architectural style, abundant razorvine, and acidic smog is all very homey to them.
Couatl are arrogant and vainglorious feathered serpents who seek to slay evil as part of their endless, convoluted dance for status and prestige in their meritocratic society.
Devils are descended from fallen angels who betrayed their divine master and murdered him, being cursed into hideous, twisted shapes. Although mostly bound to their prison of Baator, they still have freedom enough to roam the Astral Sea, either in service to wary gods of evil or else pursuing their own wicked plots.
Exalted are one of two races covering what, in past editions, were known as Petitioners. These are the souls of mortals who worshipped the gods and were chosen to enter the Astral Sea for their afterlives. Mostly they stay in their chosen Dominions, but one occasion may be given cause to travel the greater Astral Sea or even make their way to Sigil.
Exarch is the general term given to the staggering variety of lesser divinities, saints, proxies and other divine powerhouses who aren't strong enough to be considered full gods. As such individuals either directly serve the gods, or seek to complete the transformation into godhood, it goes without saying that they can be found here.
Githyanki are an ancient race of piratical raiders, driven to torment all other peoples out of paranoid fear of once-again falling to slavery, as their ancient ancestors did in the face of the Illithids. Driven by a lust for raiding and conquering, they use the Astral Sea as an impregnable defense against retaliation, whilst constantly searching for new portals that might lead to new worlds to attack and plunder.
Gods, it should go without saying, usually call the Astral Sea their home, ruling over their precious Dominions. There are some exceptions, with the Raven Queen dwelling in the Shadowfell and Torog dwelling in the Underdark, but most deities live in the Astral Sea.
Maruts are a race of divine constructs - angelic stone golems, essentially - fashioned eons ago by the gods as the ultimate impartial arbitrators and mediators, then discarded when they turned out to work all too well. Now they seek to gather a web of favors and pledges, slowly and methodically working to usurp control over the multiverse and reshape it to a more... orderly... form.
Shardminds are a race of psychic crystalline living constructs who were created when a magical crystal barrier between the Astral Sea and the Far Realm was destroyed. As such, they are frequently found traveling the Astral in an effort to understand who they are and what their place is, with Hestavar having one of the largest known populations of them in the multiverse.
Quom are a former race of gentle medics and magicians, driven insane with rage by the death of their world-god, Lakal. They now roam the Astral Sea constantly in continent-sized crystal ships, seeking to gather the fragments of Lakal so that they can restore her.
Outsiders are identical to Exalted in all ways bar one: as a symptom of what breaking the Lattice of Heaven has done, these souls are incapable of entering the Dominions of their patron deities, stranding them for all eternity just outside of their chosen heaven. These unfortunates make up the majority population of the Border Isles - smaller worldlets that orbit the various Dominions - although many choose to head elsewhere in the Astral or to Sigil, having no inherent place in the heavens.
Locations of Note
It goes without saying that the majority of locations worth taking notice of in the Astral Sea are Dominions; places either actively ruled by the gods, or created by them and then lost during wars with each other, the Primordials, and demons. But there are other areas of note; many races, particularly the couatl, githyanki, and maruts, build domiciles of their own without the need for divine intervention.
The Verdant Isles of Arvandor are a Dominion shared by Corellon and Sehanine, although Melora and Avandra also often reside here. This is predominantly the afterlife of the ruesti -- Exalted Elves -- and the home of the Seldarine, archfey turned godlings who serve the Dominion's masters. This gives it close ties to the Feywild... but also to Carceri, for reasons that have to do with its masters' objections to the Carceri Compact.
The Darkened Pillars of Kalandurren stand silent and still, a testimony to the fallen god Amoth and the demon legions that defeated him.
Pandemonium is a strange and shunned place, a rambling maze of black tunnels blasted by fierce winds, with no clear origin or purpose. It is reputed to be the forgotten Dominion of the Chained God, Tharizdun.
The White Desert of Shom is a crumbling ruin of a Dominion, once home to the God of the Word, now home to nothing but a bleached desert and the bones of all his followers, the Illumians, achieved - and then squandered.
The Red Prison of Carceri is a place shunned by the gods, created to hold the worst mistakes and monsters they knew - from the Mad God, Tharizdun, to the Abominations they and their Primordial enemies wrought during the Dawn War.
The Corpse of Haemnathuun is all that remains of a primordial known as the Blood Lord, slain in battle against Bahamut, Bane and Ioun during the Dawn War. Now petrified into a corpse-shaped mountain of blood-red stone, the corpse drifts eternally, occasionally spawning abominations known as Blood Fiends.
Erishani is a mysterious Dominion, known more than anything for the immense "Golden Monolith" at its center. Its secrets lie with the now-lost God of Guardians, Haramathur, and his ultimate sacrifice.
Archanus was once the Dominion of a deity sworn to creation and invention, a massive eternal engine of brilliant purpose... until some unknown saboteur introduced a fatal flaw that led to the entire realm collapsing, its enormous clockwork components breaking and rendering it inoperable. Now, a band of maruts seeks to understand and reconstruct the devices of Archanus.
Eldregaard, also known as the Fane of the Fallen Dragon, is a corrupted temple floating in the Astral Sea, home to a mad and twisted fallen Exarch of Bahamut.
The Forgotten Sanctuary is all that remains of a destroyed world, now floating forever in the Astral Sea.
Frostburn is a trapped pocket of elemental energies, where two elemental princesses - Sisanthak of Ice and Vorsheen of Fire - and their legions of loyal Ice and Fire Archons fight an endless and futile war for supremacy.
Mutas is a city of mortals that has come to exist in an obscure city-fort in the deep Astral Sea, said to have once been the miles-wide drinking cup of Moradin himself. It suffers an eternal blockade by fiends and githyanki, who yearn to enslave or slaughter its residents, but are barred from entry by its divine wards.
The Shivering Spires is a ten-mile-square pocket of elemental energy, taking the form of a massive pool of churning fire and acid, from which rises impossibly tall and thin stone spires amidst an eternally raging windstorm.
The Triad Islands are a collection of three astral city-states that have been locked in a three-way war for generations.
|The Cosmology of the World Axis|