Territory

Each dimension in the multiverse is a self-contained universe. The most common term for these separate worlds is 'plane', though other terms may be used as well. Every character on the MUSH is native to a specific plane. Planes are organized into sectors; ICly, they're arbitrary groupings imposed on a multiverse that doesn't always follow them. OOCly, they're there to make our grid sensible and functional.

Sectors contain planes that are similar in general 'theme'; they have nothing to do with physical location in the multiverse. The sectors were named by a few inhabitants of the 'Mundane' sector shortly after the gates first opened. Their names reflect this, and much to the dismay of some people, they've stuck.

• Mundane: The planes in this sector focus on the planet Earth, and lack high technology and supernatural phenomena. While many of these planes are set in different time periods, they all operate according to a common set of physical laws, with no exceptions. While the name "Mundane" has stuck, the various planes in the sector can be anything but; war, intrigue and touchy situations aren't all that uncommon among them.
• Paranormal: The Paranormal sector contains planes with supernatural and/or unusual elements which violate the laws of physics as understood in the Mundane sector. These elements can come in a variety of forms, and can be secret, common knowledge, or anywhere in between. Planes within the Paranormal sector tend to focus on Earth, much like those in the Mundane sector. The societies of both also resemble each other, to a remarkable degree.
• Science Fiction: Science, technology, and their products figure strongly in planes in the Science Fiction sector. In some planes, this technology is outlandish, but supported by natural laws; in other planes, it falls into line with Mundane scientific findings. As can be expected, Science Fiction societies have been shaped by their own technology, and many of their civilizations are alien, even by the standards of other Science Fiction planes.
• Fantasy: The Fantasy Sector is populated by planes that lack high technology, often possessing things that blatantly defy Mundane physics instead. Magic tends to feature strongly in these planes, though it might not be commonplace. Furthermore, many Fantasy worlds bear little or no resemblance to the worlds of the Mundane sector--some of them may bear a superficial resemblance to Medieval or Rennaissance society, but this is skin-deep at best.

On the IC grid, each sector has its own room. These aren't so much specific IC locations as generic rooms that can act as rooms for settings that don't have their own dedicated room. Players can also place objects in them to act as stand-in rooms for their own settings. If your setting doesn't fit any of the Sectors, don't worry about it--just place a room in the Sector that's closest to the base theme.

The Hub--a self-contained pocket dimension--sits at the metaphorical center of the multiverse. As far as ancient pocket dimensions go, it's pretty tame; it has an Earth-normal environment, including a light/dark cycle, a breathable atmosphere, and comfortable gravity. There's no weather, and no native biosphere, so any creature comforts of that nature have to be brought in from other planes. The Hub also contains one of the Ancients' former cities. It's utterly deserted, though it's in the process of being reclaimed by natives of the planes.

The Hub also contains the Terminus, a structure that houses the Hub endpoints of all of the static gates. The Crystal, a structure that serves as a massive radio tower, is nearby. The headquarters of the IPA are located in a reclaimed Ancient building two miles away from the Terminus; the location of the Syndicate's headquarters remains unknown.

The Hub is also protected by a potent security system. Anyone who intentionally hurts another--or attempts to cause serious damage to the Ancients' facilities--will be 'intercepted'. For all intents and purposes, the attacker disappears, reappearing a second or two later. Whatever happens in the interim is still unknown, but one thing is certain--it isn't pleasant at all.

In OOC terms, fighting in the Hub will call down the wrath of the security system upon all aggressors. The effects of the system are meant to be left ambiguous, but they're not the sort of thing most characters will risk again.