Portals

Available for public use

At its simplest level, a portal is a doorway to another universe.  Portals allow people to move from one world to another under their own power, without the aid of high tech vehicles, special abilities, or magic spells.  Very rare on most worlds, portals appear often and freely in the City, offering unparalleled access to the infinite worlds of the Multiverse.

Portals usually appear in an enclosed frame of some sort, but may be found free-standing.  Most portals are visible when active, and have a wide variety of appearances.  Some portals appear as an opaque swirling vortex of light, others might simply show the world they lead to, as if it were any normal doorway.  A few portals are invisible, and a traveller might not even realize immediately that they've stumbled into one.

New portals can be created artificially with powerful magic and technology, but the majority of portals in the City are naturally occuring.  Some rare people have the innate ability to create new portals or travel between universes unaided.

Types of Portals

No two portals are exactly alike.  They come in an infinite variety, just like the worlds they lead to.  That said, most portals can be broadly sorted into one or two common categories that describe their properties.

Persistent

Persistent portals are often called gates.  A persistent portal remains open constantly, without any apparent outside power source.  Being open and active just seems to be the natural state of persistent portals.  Travelling through a persistent portal is as simple as walking through, without any need for triggers or devices to activate it.  In fact most persistent portals cannot be closed by any known means.

Several persistent portals in the City form the basis of long-term trade routes across the Multiverse, allowing free travel and trade between the City and other-worldly governments.

Intermittent

Intermittent portals are not open and active at all times.  They open and close, either in response to an external stimulus, on a predictable schedule, or at random.  Closed portals are usually very difficult to detect without the appropriate spells, equipment, or abilities, though some may have distinctive frames that mark their location.

When open or active, an intermittent portal operates the same as any other portal.

Cyclical

An intermittent portal that follows a predictable schedule can be described as cyclical.  Most cyclical portals follow obvious patterns, such as only being active during daylight hours or the full moon, or spontaneously opening for a couple hours every day.  Others might follow more complex schedules, such as portals that are timed by astrological alignments or other rare events.  The difference between a cyclical portal and a random portal is not always evident, as it may be very difficult to work out the details of a particularly complex cycle.

Random

Random portals become active and inactive seemingly at random.  They are very difficult to predict, and may appear and swallow unsuspecting bystanders without warning.  Usually the world on the other side of a random portal lacks any predictable portals of its own, and it may be very difficult to get back home.  Random portals are rightly regarded as dangerous, and a hazard of living in the City.

Many City residents first came to the City through random portals appearing unexpectedly in their home universe.

Triggered

Triggered portals are activated by an external stimulus.  A trigger may be something simple like a short ritual, a few magical words, or applying an electric current to the portal's frame.  Other triggers are absurdly complex, require hours-long rituals or complicated mathematical algorithms.  Some portals are triggered by common objects, like a rose or a piece of quartz.  The object is usually in some way symbolically tied to the world beyond the portal.

The list of possible triggers is as numerous as the portals themselves.  Portals have been known to be activated by things as varied as common gemstones, recited poems, clutching a flower or a few pieces of grain, or whistling a specific tune.  One portal is known to activate to anyone who walks through its frame, so long as they are walking backwards.

New triggered portals are discovered by accident all the time.

Keyed

A keyed portal is a portal with a specific, usually unique trigger.  A portal activated by any jade elephant statue is simply triggered.  A portal activated only by a jade elephant statue created by the Great Artist of the Third Insectron Dynasty is a keyed portal.

Keyed portals that lead to secure places, such as small empty pocket universes, make excellent safehouses and treasure vaults.  Storied keys may come to be considered precious treasures in their own right, sought out by adventurers and treasure-hunters keen to unlock the secrets of a lost world.

It is almost impossible to detect a keyed portal without the key that activates it.  If the key is not present, the portal simply does not exist.  Worlds behind keyed portals typically cannot be reached, or returned from, by any method other than their unique key.

Induced

Induced portals are portals that are created and maintained artificially, usually using powerful magic or highly advanced technology.  Induced portals last only as long as the magic or technology that created them can sustain them, and usually require a significant amount of power.  Once the magic is dispelled or the technology is switched off, the portal evaporates as if it had never existed.

An induced portal that is somehow made permanent and no longer requires the presence of the force that created it will eventually be considered persistent or intermittent.