City of Doors; The Cage
The most famous planar metropolis in all existence is the city of Sigil. Located at the center of the Outer Planes and built on the inner surface of an enormous ring, Sigil claims to be the true crossroads of the multiverse. The city is ruled by the dreaded Lady of Pain, a mystery credited with enormous power—including the ability to bar divine beings from her realm.
Bards call Sigil the City of Doors do to its large number of portals, but the locals aren't that poetic. They just call it the Cage, a name suited to a city that's tough to get into and tough to leave. Not just physically—though unless you know a little something about portals, even that's a challenge—but emotionally. After all, what could you ever need that you couldn' find in Sigil? The place has everything and then some. It' a filthy, noisy place, with smoke-choked alleyways and crowded streets, but Sigil is alive in a way that no other city could ever hope to be.
As befits its paradoxical nature, Sigil is located in the center of an infinite plane (the Concordant Domain of the Outlands), floating above an infinitely tall spire and built inside a gigantic hollow ring of unknown material. The place has no sun or moon (see "Illumination", below) and no real "horizon," and only naïve visitors wonder aloud about what's on the other side of the ground.
The only way in or out of the Cage is through its interplanar portals. Locals claim that you can get anywhere from Sigil if you know the right portal. While that might be an exaggeration, it isn't far from the truth. See "Entering & Exiting Sigil" below, for more on the portals that give the city its reputation as the gateway to everywhere.
Of all the planar cities, Sigil is the least inimical to travelers, no matter how extreme their philosophies. If you can reach Sigil, it can serve as the launching pad for further explorations, or as an end in itself; Sigil is known for its strange inhabitants, services, and distractions.
Newcomers should hire a guide (a tout, in local parlance). As with any large city, Sigil has its bad areas, and wandering without guidance could lead into dark alleys—or worse. A tout can help travelers find fair-priced inns, places to buy essential materials, and contacts who can provide needed information...all for a fair fee, of course.
Entering & Exiting Sigil
Sigil might well hold the honor of being both the best- and worst-protected city in the multiverse. It has no walls or gates, so it has nothing to fear from sieges or any of the other threats that face a typical city. On the other hand, just about anybody or anything can walk right into the city whenever he, she, or it pleases through the portals that connect Sigil to other planes.
The portals aren't specially marked or decked out as ornate gateways, but look like average doorways, windows, arches, fireplaces, and the like. That's just what they are. Any bounded space big enough for somebody to walk or wriggle through—from a sewer entrance to a wardrobe—might double as a portal to another plane.
But a visitor to Sigil need not worry about opening his bedroom closet and accidentally tumbling through to the Abyss. Portals need a portal key to activate them—usually a specific object that has an affinity for what's on the other side, but sometimes merely a word, a gesture, or the right state of mind. Without the correct key, a portal is just an open space. The city's natives are more than happy to sell keys to specific portals, or at least sell the knowledge of a key's nature.
Some portals don't cooperate with the commercially minded, however. Many don’t linger long enough to become well known, and some don’t lead to thesame place twice in a row. But since nobody knows how to make or control portals, little can be done to improve the situation.
Furthermore, there’s no way around the portals, no special back door to get into or out of the Cage. You can’t call or summon creatures into or out of Sigil (even with a gate spell), nor can you use plane shift to get in or out. You also can’t use astral projection, although, strangely enough, the various teleportation spells work just fine within Sigil itself. Since the city resides on the Outer Planes, no connection to the Ethereal Plane exists. Even the deities themselves can’t (or don’t want to) overcome these restrictions.
If the DM allows it, a character who makes a succesful DC 25 Knowledge (the planes) check knows of at least one portal on his home plane that purportedly leads to Sigil. That’s not saying that the portal won’t be hard to reach or fiercely guarded, but the route can be discovered.
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 the first two factors and an overabundance of the third, and its architecture amply demonstrates that fact.
There’s nothing to build with in Sigil. The “ground,” though hard and sturdy, isn’t stone, and its material crumbles to dust when excavated. The place has no trees to turn into lumber, and the only plants that thrive in Sigil are tough, spiky varieties such as razorvine and bloodthorn. 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 tornadoes, and what passes for weather 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 kinds of structures suit their fancy. What’s more, they build wherever they like, with no thought to overall city planning.
As a result, 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 elf villas. A faithful reproduction of an Abyssal palace stands proudly overlooking the street, while around the corner a white marble shrine to Pelor is tucked into an alley. 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 elf inn, and its stone fireplace was carried rock by rock from the ruins of a foundry twenty-three blocks away.
Despite the lack of a sun or moon, Sigil enjoys days and nights 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 at antipeak, and then the 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 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 that are sensitive or vulnerable to bright light or sunlight the freedom to go about their business with relative ease.
Laws & Society
Because of Sigil’s role as the melting pot of the planes, it’s easy to see how the city might seem like little more than a recipe for anarchy. How can a place where devils and demons rub shoulders with archons and slaadi hope to maintain order? In truth, three factors keep the city relatively stable.
The first is the Lady of Pain. This enigmatic being—possibly a deity, but no one’s sure, since she doesn’t allow worshipers—moves calmly and silently through the streets of Sigil. With a mere glance, she can cause creatures to sprout wounds and bleed like a fountain. Someone who manages to get on her bad side finds himself banished to an extraplanar maze, where he’ll likely die of starvation (or even old age) searching for the single hidden exit. Somehow, the Lady keeps deities and beings of similar power out of the Cage despite its portals, so a coup to depose her isn't an option.
The second factor keeping the city intact is the dabus, the strange, alien servants of the Lady of Pain. These silent, humanoid creatures serve as workers, patching the streets and shoring up buildings; as arbiters of justice, run- ning the city courts; and, when necessary, as peacekeepers, putting down riots and the like. However, the dabus don't bother themselves with quelling petty crimes, so the streets are far from safe.
The third leg propping up the social order in Sigil is a flimsy one: the people themselves. In the heyday of the factions (see "History" below), everybody knew who was in charge of law and order. Now, the closest thing Sigil has to a police force (not counting the dabus) is a citizen group called the Sons of Mercy. Unfortunately, without any official power to make arrests or carry out sentences, the Sons of Mercy don't garner much respect from the locals, and thus aren't terribly effective in limiting crime. Similarly, the so-called Sigil Advisory Council, founded by former members of the faction known as the Transcendent Order, might have the city's best interests at heart, but the group lacks real political power.
No one knows how Sigil came into being. Some say it was build ten thousand years ago by a deposed duke of Hell. Others claim it was unconsciously created by an insane demi-god while he dreamed in an extra-dimensional prison. Still others contend it was constructed from the leftover bits of the Outer Planes just after the time of creation. Inhabitants of the Cage don't care about their city's origin. Still, nearly everyone agrees with the following handful of historical facts:
In some distant past, Sigil was run by guilds—powerful organizations that kept order and peace—and the philosophy-based factions were nothing more than dozens of splintered groups that squabbled incessantly among themselves. Then, six or seven centuries ago by most accounts, came the Great Upheaval, when the Lady of Pain decreed that the fifty-plus warring factions would be cut down to a mere fifteen. Despite this shock to the system, people agreed it was a good decision, because it ended countless feuds nearly overnight. Unfortunately for the guilds, it also meant the end of their power structure, as the factions quickly came to dominate local politics.
The stability proved short-lived. Soon enough, those fifteen factions started putting themselves on pedestals, each believing that its way was the right way, both for its members and for Sigil itself. The factions grew to believe they had a right to run the city. A few years ago, though, the political strife turned physical, and the streets ran with blood in the Faction War.
The Lady decided to start over again. As commandments go, it was a simple one, delivered to the leaders of each faction: "This city tolerates your faction no longer. Abandon it or die."
Opinions varied as to what exactly the Lady meant by that, but everyone paid attention. Three of the factions simply disbanded, ceasing to exist. Six more moved out of town to other locations and kept preaching their beliefs to any who would listen. The other six remained in Sigil but gave up on anything resembling an organization. Whether those six were the bravest—deciding that the Lady meant "no factions" but not "no beliefs"—or the most foolhardy is open to question.
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.