Sigil, also known as the City of Doors and the Cage, is a ring-shaped city that hovers (presumedly) above the infinite Spire in the center of the Outlands. It is ruled over by the Lady of Pain, a frighteningly powerful and mysterious figure capable of controlling the city's portals and preventing deities from entering the city.
The city is said to be the fulcrum point for all of the planes, and as a result whoever can control the city controls the multiverse. This is why the city up until recently has been run by competing factions. Each faction believed that if it controlled Sigil, the Center of All, it would be able to control everything there is. As a result, the Lady of Pain kept the Factions (and many other power brokers in the city) in balance.
Sigil is shaped like a torus, or a tire, curved both longitudinally and latitudinally but open along the inner circle so that the other side of the city is visible in the "sky." It is utterly dependent on the portals for all trade, air, water, and resources. The city is often cramped, though at the Lady's whim streets and buildings will occasionally shift, appear, and disappear. The air is often polluted, and acid rain is a problem in the city again because of the lack of easy air flow. Sigil does not receive any true sunlight, so without special assistance plants are difficult to grow. Razorvine is a notable exception to this rule as it can be found growing at tremendous rates throughout the city. The city is tended to by the dabus, who repair buildings and trim the razorvine.
There is no 'outside' of Sigil and it is sealed against teleportation, planar spells, or any other work-arounds to enter the city including epic magic. It's portals or nothing. While it is said to be atop the Spire (and some claim to see it hovering there on a clear day), there has never been a successful attempt to climb into Sigil from below. In a similar fashion no one - or almost no one - has ever returned from jumping out of the 'side' of Sigil. The side of Sigil appears to lead nowhere, and those foolish souls who jump may fall forever, become erased from existence, or end up in an entirely random plane.
Sigil has no sun or moon; the sky brightens toward noon (known as Peak in Sigil) and darkens until midnight (known as Antipeak), with no apparent source for the lumination.
History
It's been surmised that Sigil's origins lie deep in the Age before Ages during the age of the Elder Brethren, before the gods or lords of the elder elements came into being. Others claim that the City of Doors was founded over 10,000 years ago by an exiled duke of Hell, unconsciously created by an insane demigod dreaming of an extradimensional prison, or constructed of left over bits of pieces of the Outer Planes just after the time of creation.
The fiends discovered Sigil early in their history, shortly after the beginning of the Blood War, before they began focusing on the corruption of the Prime Material Plane. Initially they tried to use it to launch invasions of one another's planes, but the Lady of Pain cast them out until they learned the City of Doors was not theirs to control. It is said that early in Sigil's history, before the Crowning of Ra, during the age of the great illithid empire, Sigil was covered in jewels. What happened to these gems is not at all clear.
Currently it is 127th year of Factol Hashkar's reign. Dating in Sigil is generally counted from the beginning of the reign of each ruler of the Fraternity of Order, as they are Sigil's primary historians.
Geography and Climate
Architecture
In most cities, the architecture depends on three factors: the building materials available, the environment, and the dominant style and personality of the locals. Sigil has none of those things, and its architecture demonstrates that fact amply.
There’s nothing to build with in Sigil. The “ground,” though hard and sturdy, isn’t stone, and it crumbles to dust when excavated. The place has no trees to turn into lumber (the only plant that seems to thrive in Sigil is razorvine; see below). You can’t even dig up sod or mud to build a crude hut. Every piece of material in every building on every street is imported from another plane. No two buildings are made from the same materials or designed the same way.
Sigil doesn’t have much of an environment to shape its architecture, either. It never gets very hot or very cold, it has no monsoons or tornados, and what does pass for weather just tends to make everything look gray and dingy. Thus, since the inhabitants don’t have to worry about their houses surviving the next big storm, they build whatever kind of structures suit their fancy. What’s more, they build wherever they like, with no thought to overall city planning. Finally, Sigil has no dominant style. The look of the city reflects the fact that its residents come from everywhere.
Dwarves build sturdy stone structures next to graceful elven villas. Down the street stands a faithful reproduction of an Abyssal palace, and tucked into a nearby alley is a white marble shrine to Pelor. On top of that, since it’s easier to scavenge than to import, half (or more) of the buildings in Sigil are ramshackle affairs thrown together from the parts of a dozen other constructions. The gorgeous darkwood facade of that tavern probably came from an old elven inn, and its stone fireplace was carried rock by rock from the ruins of a foundry twenty-three blocks away.
Illumination
Despite the lack of a sun or moon, Sigil enjoys days and nights much like any terrestrial city. In the early hours of the morning, the sky slowly brightens, reaching a peak of illumination as bright as the noonday sun in a mid-latitude city (tempered somewhat by the near-perpetual haze). After peak, the illumination fades over the next several hours until darkness reigns, and then the whole cycle starts over.
With no moon or stars, of course, “night” in Sigil isn’t like a typical country evening. If it’s clear, though, you can usually make out the flickers of torchlight and lanterns from the other side of the city high above (remember, the city’s built on the inside of a ring, so the far side of town is directly overhead). All told, over the course of 24 hours, Sigil has about 6 hours of bright light and the same amount of darkness. The rest of the day resembles twilight, allowing beings sensitive or vulnerable to bright light or sunlight the freedom to go about their business with relative ease.
Flora and Fauna
Razorvine
The flora of Sigil isn’t much to write home about. The foul environment makes short work of most plant life, so visitors shouldn’t expect to see much greenery. In fact, the only plant that seems to thrive in the Cage is a horrid, twining climber called razorvine.
Spread from the Lower Planes—no doubt via portals in the Lower Ward — the kudzulike razorvine grows everywhere it can in the city. The dabus keep it in check in most places, but everybody knows you can’t really ever get rid of it. Even trimming it down to a stub only delays the inevitable, because razorvine grows a foot or more per day. And as its name implies, the vine is as sharp as a knife, so you can’t just yank it out of the ground. In fact, even reaching your hand into a patch can leave you bloody.
Some Sigil residents have turned razorvine to their advantage. With care, a patch of razorvine can be cultivated to provide protection. After all, most burglars aren’t desperate enough to scale a razorvine-covered wall to see what’s on the other side. And since the plant becomes dull and brittle when cut, it also makes fine kindling.
People
Population
Sigil ordinarily has a population of over a million, but two-thirds of those are transitory, staying in Sigil only on the way to somewhere else. The city's current demographics are around 37% human, 20% planetouched (aasimars, mephlings, neraphim, tieflings, and the like), 10% elves, 10% halflings, 3% dwarves, and 20% other. Bariaurs make up a sizable chunk of the population. Fiends, celestials, modrons, and slaadi are present in the city in large numbers, but few find it pleasant enough to justify staying long. The fiends miss the carnage of the Blood War and the celestials look down on the city's coarseness and grime.
The only ones who call themselves Sigilians or Cagers with pride are the dabus, those faction members born in the city, and a few families who've settled in Sigil and made it their home. They tend to look down on others as outsiders and intruders, which helps cement their reputation as arrogant snobs. Some emigrants from the Prime Material decide to stay in Sigil on purpose, but many more are gate-orphans, also known as the Keyless or Marooned, who have entered the Cage through one-way portals and are unable to find their ways back home. Few souls of the dead venture into Sigil; those that do usually serve deities of neutrality or travel.
Religion
Planewalkers tend to be a pragmatic lot, and so temples that focus on healing tend to be more popular among them than those that do not. This means that temples of Apollo, Diancecht, Frigga, and Pelor have influence and power in the Cage far exceeding the rank and status of the deities they represent.
Languages
The primary language of Sigil is known as Planar Common, or Planar Trade. This is the same as the Common tongue spoken on the Prime Material Plane (though with specific slang, called the cant), having been introduced to the planes by explorers from the Prime. Other commonly spoken languages in Sigil include the Lower Planar trade tongue, Archon, Asuras, Baatezu (Infernal), Baku, Bariaur, Bladeling, Dao, Djinni, Efreeti, Eladrin, Formian, Gehreleth, Githyanki, Githzerai, Guardinal, Khaasta, Marid, Mephit, Modron, Nereid, Night Hag, Slaad, Sylph, Tanar'ri (Abyssal), Tso, and Yugoloth. The Celestial tongue (of which Archon, Asuras, Eladrin, and Guardinal may be dialects) is also surely common in Sigil. Note that the genie tongue is known as Jannti, and the elemental tongues are Aquan, Auran, Ignan, and Terran.
The dabus, the Lady of Pain's enigmatic workers, speak using illusionary symbols that appear above their heads, spelling out words using rebus puzzles. The Lady of Pain does not speak at all.
Government
Prior to the Great Upheaval, Sigil was primarily ruled by guilds. Now, 15 factions control Sigil's government. The true ruler of Sigil, however, is and has (as far as anyone knows) always been the Lady of Pain, a mysterious being of unknown race resembling a robed, serene-faced woman of gigantic size wearing a headress of blades. She appears and vanishes according to her whim, only interceding in her city's affairs when the need is dire, or to punish those who attempt to worship her as a god. She has been known to flay her enemies alive with her razor-edged shadow, or banish them into demiplanar Mazes.
Administrative Divisions
Sigil is divided into six regions called wards. The wards aren’t official designations—no walls divide them from one another—but everyone knows the difference between one ward and the next, even if they don’t agree on exactly where that difference begins and ends. Still, it’s important for visitors to know what’s where, so they don’t wander where they aren’t wanted. In some locales, that might earn them a warning, but in others, it might get them a knife between the ribs.
Lower Ward
The Lower Ward is perhaps the most symbolic of the Cage as a whole. It gets its name from the large number of portals to the Lower Planes found there, portals through which a foul, sulfurous stench billows, filling the area. Still, it’s hard to avoid the Lower Ward, since most of the city’s craftsmen live and work there, and the place is full of forges, mills, warehouses, and workshops.
The Lady’s Ward
Going counterclockwise around the ring of Sigil, the next stop is The Lady’s Ward (and yes, the locals can hear you capitalize all three of those words). The Lady of Pain doesn’t actually live here, but rich citizens and most of Sigil’s temples lie within this ward. The Lady’s Ward has power, wealth, and majesty, and knows how to show it off.
Market Ward
In the Market Ward, everything is for sale. The wealth of Sigil may be concentrated in The Lady’s Ward, but it’s spent here, whether on goods, services, information, reputation, or anything else your heart desires. The best place to get it all is the Grand Bazaar, an immense plaza filled with shops, tents, and stalls offering wares from dozens of planes and strange worlds. As the old saying goes, if you can’t find it here, it probably doesn’t (or shouldn’t) exist. Prices can vary wildly, from dirt cheap (for merchants with an unexpected overstock) to many times the normal value (for goods in sudden short supply, due to a faulty portal or a band of planar marauders).
Guildhall Ward
Many visitors can’t tell the difference between the Guildhall Ward and the Market Ward. Even some locals claim that only tradition separates them. Since guilds haven’t played a particularly significant role in Sigil for centuries, one can guess that the name itself owes a lot to tradition. Today, the Guildhall Ward serves as the domain of the middle class of Sigil. Many merchants who hawk their wares in the Market Ward during the day sleep here at night, and many who deal in services (rather than selling finished goods) live and work here as well. The Guildhall Ward also houses many racial neighborhoods, from the transplanted halfling hill of Curly-Foot, to the bariaur neighborhood of Ghundarhavel, to the githyanki community of Git’riban.
Clerk’s Ward
The Clerk’s Ward holds the bureaucracy of Sigil, and most of the faction headquarters are located here. the Clerk’s Ward is also home to one of the flashiest places in the city — the Civic Festhall. Run by the Society of Sensation, the Festhall combines the best aspects of a concert hall, museum, and tavern while simultaneously serving as the centerpiece of an artistic neighborhood that brings travelers from across the multiverse. It’s the best place in Sigil to see or be seen.
The Hive
Many locals claim that the Hive isn’t a ward so much as it’s the lack of a ward. Both the name for the region between the Lower Ward and Clerk’s Ward and for the chaotic, sprawling slum in its center, the Hive crawls with scum and villainy of all stripes. The lowest of the low live in the Hive — those who can’t afford (or don’t dare) to rub elbows with the more fortunate folks. In effect, the Hive is like a miniature version of Sigil itself, with everything that is needed in daily life: taverns and inns aplenty, entertainment, and services from escorts to sellswords. The quality may be questionable, but the prices can’t be beat. The Gatehouse Night Market offers nearly everything one could find in the Grand Bazaar (and a few things one couldn’t), though it’s best not to think too hard about where they came from.
Economy
Sigil is a massive center of planar trade, its markets second only to the City of Brass. Goods and services may flow to the city from any and all other planes, depending on which portals are available to planar merchants. Sigil has no natural resources of its own, though it has a sizable manufacturing economy in the Lower Ward.
Currency
A good deal of commerce takes place simply through bartering one good for another. Particularly prized are wood from exotic trees, fruits, vegetables, and ore. Since it is a planar hub, there are a multitude of different coins from a hundred worlds in circulation. Most are made of the usual copper, silver, and gold, simply bearing different seals of deities and rulers though they are all accepted regardless of style. Some trade in thin sticks of metal, called bars, and they are valued as five coins of the same metal. Some of the stranger coins from far-flung worlds are made of steel or ceramic. While rare, steel coins are roughly equivalent to silver in value, while the ceramic are worth little more than copper and are not universally accepted.
Transportation
Ordinary horses tend to get sick in Sigil's choked, smoggy atmosphere, so most travel is by sedan chair, walking, or using planar steeds like the Arcadian pony or the nightmare. Some shipping occurs in the foul body of water known as the Ditch, which has a portal on it leading to bodies of water on other planes. Sigil is the City of Doors, so of course it is best known for the portals that may open in any bounded space to anywhere in the multiverse. These portals may be permanent or temporary, and seem to follow predictable schedules for the most part, although they may be destroyed by mortals by breaking the border of the space, or sealed up with magic, and the Lady of Pain may change their destinations at her whim.
Military
The Harmonium are Sigil's police force (prior to the Harmonium's arrival, the Doomguard seem to have served that role, and before the Great Upheaval, the Sodkillers seem to have done it).