This is a standard superhero game. The players are a new group of heroes starting out in the city or area of their choice. The world is currently populated with many different hero groups. Some are incompetent, some corrupt, but others are reliable. In the beginning, the heroes will work in their own area and be little known outside of it. As the campaign goes on and the characters gain experience, they will start interacting with heroes and others across the world.
World Description: The world is much like our own except for the existence of super-powered humans. Magic exists in this world, and works for those who know how to use it. Mages who can generate superhero-level power are few and far between, but individuals with a small amount of magical ability are not all that rare. You can usually find such people in any decent-sized city offering their services for hire. The buyer should be careful, since it can be difficult to spot a fraud.
History: There have been tales of super-powered individuals throughout history, but the first known and verified ones were discovered in the post-WWII 1940's. In 1950, U.S. intelligence claimed that they had discovered evidence that the Soviet Union had embarked on a new program of research into the causes and effects of power-inducing mutations. President Truman announced the creation of the Special Powers Project. This agency was to do research on superhumans, as well as to develop new technological ways of dealing with super-criminals. Large amounts of funding were poured into Special Powers by the government. Some of this went to national labs like Fermilab and Oak Ridge, but most of it was contracted out to private companies like Lockheed and the UCF corporation. Some superheroes joined up with Special Powers, but the best and most experienced kept operating independently.
In the early 60's, a bomb was exploded above Lake Michigan which released mutagenic chemicals into the environment. This act was attributed to a group of disgruntled technicians recently fired from Fermilab. The chemicals spread throughout the country and the world. They caused a large number of birth defects and deformities, but many other people developed powers due to genetic alteration. Thus the late 60's and the 70's saw the number of supers booming. Some of these became criminals. Some went to work for Special Powers. Others joined corporate-sponsored groups that were forming at the time. The most effective ones continued to be in groups that functioned with no support and kept their identities secret.
A growing backlash movement against superhumans had developed by the late 80's. This movement was started by fundamentalist religious leaders who denounced superhumans as "perversely abnormal abominations against the design of God". Other people joined the movement who were not religious but were paranoid of people who could do things they couldn't and refused to tell anyone who they were. Still others were resentful at the worsening economy and rising unemployment, and found superhumans to be a convenient scapegoat.
Character types: This game is very flexible. Characters can have powers of any special effect type that is seen in the comics. Overly "Dark and Gritty" types are not recommended -- at least I don’t want to see a whole group full of them. The characters should be able to get along with each other on a personal level at least well enough that they’d want to stay together in the same group.
Morality: (3) - Some cross-over between good and bad. Morality is mixed in this campaign. On the one hand, the player characters are expected to be heroes. This does not mean that they have to be the classic four-color law-abiding defenders of truth, justice, and the American way. It does mean that they should be people who are trying to work toward a better world for all, and willing to take risks in the process. Of course your character’s reasons for doing this and his/her idea of what makes a better world might be far different than the next character’s...
On the other hand, your adversaries are not always going to be villains as such. Most of your important foes will have realistic motivations for doing what they do. Very few people doing bad things will be doing them just because they are "bad people". They have their reasons. Sometimes those reasons might put them on your side, if only for a while. Likewise, any NPC’s who are normally on your side are there because they have their reasons, and they aren’t always going to be there either.
Realism: (2) - Romantic. Realism is not heavily enforced, and if a PC tries something creatively risky I’ll usually let it work unless there’s a reason why it can’t.
Outlook: (2) - Optimistic. The PC’s will almost always have a good chance to solve their immediate difficulties. Long-term problems will be harder to deal with.
Seriousness: (3) - Balanced. This game is basically serious, but there will be a fair amount of comic relief.
Continuity: (4) - Mostly serial. Campaign continuity will be enforced. An apparent discrepancy probably indicates that there’s something going on that you don’t know about (although it could just mean that I screwed up).
Literature Equivalent: Present-day comic books, like the DC or Marvel universes.
Thanks to Matt Posner, from whom I borrowed some of the events in the game history.