Virtually anything you can think of, from the more usual sort of powers (telekinesis, firestarting, etc.) to the totally lame (I CAN MAKE THINGS CHANGE COLOUR WITH MY MIND). They can be as strong or weak as you like, subject to whatever limitations you like - although the mods reserve the right, of course, to not accept powers that are not limited enough. We also reserve the right to cap powers - we don't want a dozen telekinetics, thanks!
At this time, the only powers that are absolutely banned are mind-reading and mind control, and various other imitations of them. This is because the only real use of these powers is for godmodding, which is absolutely not allowed. It is possible for a sufficiently weak form of one of these to be accepted - for example, being able to read auras to tell emotions, but not motivation or intention - but it will be heavily regulated.
What precisely do you mean by "limitations"?
In order to keep any one character from being too powerful, we would like all powers to have some sort of limit. This can be anything from the obvious (he can only lift up to two hundred pounds with his mind) to the bizarre (if she heals a fatal injury, she starts hallucinating and is effectively useless for two days because of being nuts). If we feel a character is not balanced well enough, we will ask them to be more limited. In general, though, this should not be a problem so long as you keep in mind that a) godmodding is not allowed, which is the purpose of these limitations, and b) characters who are totally awesome at everything are pretty boring, actually.
How gone is the magic?
Gone. The magic simply doesn't exist in this world; it won't work with a wand or without. In addition, inborn magical powers (like being a Metamorphmagus) will also disappear. Creatures, however, are still creatures; it's not a cure for lycanthropy, unfortunately!
Where can my characters live?
All characters live and work in the Tower, a fifty-story-high building in the center of the city. Though the top five floors belong to the Master of Ceremonies and are unreachable, the others are connected by stairs and lifts; floors twenty to twenty-five are residential, and the rest contain shops, eateries, laundries, storage rooms, and everything else necessary to survival. You will be assigned a flat and (possibly) a roommate upon acceptance.
Though it is fully unnecessary to leave the Tower except on missions, the rest of the city is available to be explored; it can be expected that the Death Eaters and the Order will quickly set up secondary bases within the city.
How do jobs work?
Upon arrival, each character will be offered a list of three occupations and asked to choose one; if they refuse, one will be chosen for them. They do not get paid - rather, the Tower operates on the assumption that if you provide your services to society, you are deserving of the material goods provided. Those who refuse to work will be imprisoned, since they are no longer contributing members of society.
How do the journals work?
Each character is given a journal when they arrive, which comes with their letter from the Master of Ceremonies describing where they are and what is happening. The journals are all connected magically, and people can write to each other privately by drawing a box around the words they specifically wish to hex to someone else, and writing that person's name at the top. Entries or partial entries can also be anti-hexed, against a certain person or persons, by use of a symbol.
Therefore, unlike in other games, we only allow hexes to specific people, since the magic only works with the names actually written in. If a certain group of people (e.g. the Order, the Marauders, the Death Eaters) is hexed, you may use that as shorthand to avoid having to list all the members, but remember that the character will be writing in each individual name, and those lists can get awfully long.
A simple explanation of this system can be found on the front page of each journal, so all characters will be on the same page!
What is the game calendar?
Although there is effectively no year, the game runs in real time - Sunday, the seventh of February is still Sunday, the seventh of February. Characters can find the date in their journals. Full moons also run according to real time.
What level of technology is there?
There's a bit of a hodgepodge of technologies here, but one thing is for certain: you won't find anything too modern. No computers, no telephones, no television, etc. However, the lifts run on mechanical power, and there are clocks, relatively good medical equipment, microwaves, toasters...basically, if you're not sure whether a certain technology falls into the category of allowable, just ask!
And yes, it all runs on good old eckeltricity.
How do the missions work?
Let's start with the OOC mechanics. A few days before each mission (which will occur at least once every two weeks, sometimes more often), the mods will post a request for volunteers. Therefore, if you as the player will not be available, you are under no obligation to participate. Characters put up will be chosen OOCly, sometimes at random, sometimes for plot or character related goodness, for example if we think it would be exciting for a lone Order member to be surrounded by Death Eaters.
ICly, characters have no choice in the matter. Everyone will be entered into a lottery, and informed a day or two prior to the mission that they have been called for duty. Anyone who refuses to participate in the mission will find themselves locked up...or worse. In order to ensure that as many people as possible get to participate, no character can be chosen for two missions in a row.
These missions will consist of the characters being asked to complete various tasks. Some will have obvious consequences - there's a rampaging troll, go get it! - and some will be more cryptic - take this mysterious black box to this address.
What is the Dark Menace?
Characters are told only that there is a Dark Menace threatening the city, and that it is their duty to assist the Master of Ceremonies to hold it at bay - and eventually, destroy it utterly. It is impossible to tell if the Dark Menace is human, demonic, or something else entirely; it seems to be blamed for everything that goes wrong in the city, from animal attacks to blackouts. However, given that people do go missing or turn up dead because of it, one thing is certain: it is most definitely a threat.
So what's going on with Voldemort?
Voldemort is an NPC; upon arrival, he decided he refused to live under the thumb of the Master of Ceremonies, and left the Tower. Since his power is invulnerability to physical attacks, this means he, unlike his followers, is capable of surviving in the deserted city. He is classified as a renegade, and anyone who attempts to follow him into exile will be killed or captured if possible; Voldemort asks his Death Eaters to remain in the Tower as spies, and calls meetings every so often. He is quietly plotting to take over the Tower.
Why isn't the Master of Ceremonies on the PB page?
Because he hasn't got a PB! Nobody ever sees him; he's like Charlie, in a way.