The Outlands, known as the Plane of Concordant Opposition to those fond of syllables, is a plane of rolling hills, and flat, fertile countryside. It is a plane temperate in its temperment, hardly extreme or fantastical at all. It is said to be the plane of neutrality, or of no alignment at all, and both thing seem to be true to varying degrees.
In general, the Outlands resembles the earth and sky of many material worlds, but less extreme - temperatures may vary, but it is rarely life-threateningly cold or warm. There may be seasons, but they are mild. There are low mountains and shallow valleys, dry-but-not-desolate deserts and steamy-but-not-stilfing jungles. There are large villages and small towns, but no isolated enclaves or immense cities. Much of the land is fairly flat and prairie-like, and fairly well-suited to agriculture.
Creatures from all over the planes use the Outlands as a meeting-place, battle-ground, and buffer-zone. Celestials and fiends march through here, and modrons and slaadi visit its towns and villages. Sometimes, great battles are fought here where armies of immortals clash, and the people of the Outlands can often be cought in the crossfire.
From anywhere in the Outlands, one can look to the "center" to see a massive spire rising up out of the earth. If you walk towards this spire, you find magical powers becoming limited and tamped down the closer you get to it. Even deities experience this limiting effect, stripping them of divine powers and leaving them little more than mortal if they come to the center. This doesn't affect many inhabitants of the Outlands (who tend to be commoners, farmers, laborers, and the like) - in fact it often keeps them safe from the predations of powerful spellcasters - but it's an important consideration for travellers. Many of the largest cities on the Outlands are toward the edges, where the magical dampening effect beings to wear off.
Atop the Spire, one can see a ring - that ring is Sigil, the City of Doors.
Effects on MagicEdit
Aside from the dampening effects of the Spire, there are a few things to note about casting magic on the Outlands. Many categories of spells that need to reach the inner planes are neutralized without the proper spell key. Spell keys on the Outlands flow from a theme of balance: to access the plane of fire, one might need to add water to the casting of a spell, or to access the plane of air, some earth may be added. Spells that tap negative energy require a live insect, while spells that tap positive energy require a dead one. Spells that access the Shadowfell need light and darkness as part of their casting to function here.
Elementals conjured up on the Outlands are actually created from the stuff of the plane itself, and so inherit the neutral outlook of the Outlands. This doesn't necessarily affect their behavior that greatly. but a caster might find an elemental more symmetrical or prone to flanking than would otherwise be the case.
Deities residing on the outlands may grant power keys to enhance the casting of spells that reveal, maintain, or abjure Good, Evil, Law, and Chaos.
Spirits incarnating on the outlands tend to not get very involved - they're more concerned with their day-to-day activities than with travelers and adventurers. They live here much as they may have in life, farming, herding, working, or otherwise simply watching the days tick by without much struggle. They're milquetoast and the like it that way.
If a petitioner is provoked into some great action, they often feel compelled to compensate for it by mirroring it in some way. One moved to take pity on a wounded adventurer may rob them and leave them for dead on the road the next day, for instance, correcting some karmic balance, at least in their mind. This may be part of the reason many of them simply don't get involved - one can easily get trapped in an endless loop of compensation for past deeds of various sorts, and it can be hard to get along with others when they know you'll reverse your action eventually.
Locations on the OutlandsEdit
Tir na OgEdit
A large, sparsely-populated realm of multiple deities from the Celtic pantheon
The Well of UrdEdit
A well at the root of Yggdrasil where the three Norns foretell the fate of all.
The verdant, pastoral realm of Sheelya Peryroyl, the halfling goddess of nature and agriculture.
The Dwarven MountainEdit
A tripartate realm of three dwarven deities: Dumathoin, Dugmaren Brightmantle, and Vergadain.
The gloomy realm of the patron of the lizardfolk
A dark realm of illusion and deception, home of the beholder deity of air, Gzemnid
The Caverns of ThoughtEdit
A humming, maddening place home to the illithid deity of mental prowess and knowledge, Ilsensine
A large, bustling palace presided over by the Judge of the Dead in the Celestial Bureaucracy, Yen-Wang-Yeh
A sooty place of brilliant invention sacred to a god of artifice.
The Pharonic god of knowledge presides over this realm of plenty from the city of Thebestys, where a library that holds the answer to any question can be found.
The Hidden RealmEdit
The home of the giantish god of knowledge and creation, Annam, hidden high in a mountain.
The Mausoleum of ChronepsisEdit
The lair of the draconic god of fate, which holds hourglasses measuring the life of every dragon.
The gate-town of Mechanus, where an ordered society of light is mirrored by a criminal underbelly.
The gate-town of Pandemonium, where the mad rule and the sane sit inside walled citadels.
The Court of LightEdit
The realm of the tripartate naga goddess of wisdom and healing, Shekinester
The gate-town of Carceri, where outcasts on the run can find refuge - but not from each other.
The gate-town of Ysgard, where bold heroics and personal glory are valued above all.
The gate-town of the Abyss, a vile place of continual backstabbing
The gate-town of Baator, where a cheerless iron prevails
The gate-town to Limbo, where the ever-changing landscape hides masters of craft.
Mobile encampments of wandering bariaur crisscross the land
Lone buildings and towers dot the landscape, the homes of those that wish to be left alone.
Out pas the spire's magic-negating influence, the land becomes unstable and strange, hiding things undreamt-of on the Great Ring.
Villages run by the Free League, who ensure that each village remains its own enclave. They don't take kindly to bossy strangers.
Marching armies of fiends or celestials that don't know how to get to the battle, or how to get home.
The River Ma'atEdit
A wide, warm river near Thoth's Estate.
Great fortresses on chicken-like legs that wander when their owners desire.
The gate-town to Elysium, a quiet place of contemplation
The gate-town to Celestia, a city of order and goodness and kindness made insufferable. Rejects all who are not part of it.
The gate-town to the Beastlands, a city of tents over ruins in a jungle
The gate-town to Arcadia, a strict law enforcing a sterile beauty
The gate-town to the Gray Waste, a place ruled by a sadistic artist with a cadre of beholders
The gate-town to Acheron, a grim military encampment
The gate-town to Arborea, a place of riotous merriment.
The gate-town to Gehenna, with greedy, vicious people in the shade of volcanoes
The gate-town to Bytopia. One of the biggest markets on the planes outside of Sigil.
Manual of the Planes (1e)
Planescape Campaign Setting (2e)
Player's Primer to the Outlands (2e)
Manual of the Planes (3e)