The MIT IAP Mystery Hunt is an annual tradition which has gone on since 1980. It was started by Brad Schaefer, a student at MIT who decided to organize a campus-wide puzzle competition. Brad organized the first hunt that January, and every year until he left the institute in 1983. From that point on, the team who won each hunt has taken over to create the hunt for the subsequent year. At the start of the hunt, all of the teams congregate in MIT Lobby 7, where the administrators explain the rules of the hunt and pass out packets.
Teams can consist of any number of people, but usually contain about a dozen participants.
A trend seems to be starting where some of these members are involved remotely, using email, phone, and fax to participate with their team. There are typically somewhere between 30 and 40 puzzles to a hunt. Although it is not required that all participants have some sort of MIT affiliation, most teams are made up predominantly by current MIT students.