Puzzle Hunt is a puzzle hunt, that is an interactive event for people who want to complete puzzles and logic test. The PuzzleHuntCMU group's variety is usually a day-long event for teams of 2-5 that incorporates logic puzzles as well as a plot and sometimes interactive puzzles. It often takes Way Too Long but is also Lots Of Fun. It occurs roughly every semester.
History of Affiliation with KGB
Puzzle Hunt was originally a KGB event. It was written and produced by members, pizza lunch and props were sponsored by KGB dollars, and mostly KGB members participated. As the event became more well-known on campus though, non-members made up a larger group of participants. In the 2008-2009 range, some KGB members believed that KGB should no longer be associated with Puzzle Hunt while others saw no reason to deny them funding. This small issue of funding responsibilities was eventually resolved in Fall 2011 when Facebook offered to sponsor the event.
Since then, the hunt has been sponsored by Facebook and Dropbox in various semesters. The staff and participants are still largely (though not solely) comprised of KGB members, and the Puzzle Hunt planning wiki still exists on KGB's website. The event is un-officially run by a group which adopted the name PuzzleHuntCMU on Facebook and is not a CMU-recognized organization.
Spring 2007 - Soviet Alice in Wonderland
Fall 2007 - Where in the World is Carmen San Diego
Spring 2008 - Hackorp / Trust Busters
Fall 2008 - Psychic Agents for Geller Hotel (highly interactive, teams of psychics solve to recover their powers)
Spring 2009 - Wibbly Wobbly Timey Wimey (time travel)
Fall 2009 - Cerulean Augmented (teams learn they are clones of one another and have to make decisions on what to do with other teams)
Spring 2010 - The Wizard's Elemental Tower (adventuring party to find the wizard who was once thought bad but is revealed to be a good guy in danger)
Fall 2010 - (Hunt didn't happen this semester because we were all lamers)
Spring 2011 - Jackson Detective Agency (film noirey detective story with a mayor, an adultering wife, and three mob bosses)
Fall 2011 - Babel Systems (Aperture Science-esque, teams must escape from industry)
Spring 2012 - The Great Library (Myst-inspired, teams world-jump in order to rebuild and return to their own home)
Fall 2012 - The Weathermen (CMU alternate universe with a weather machine and conspiracy theorists)
Spring 2013 - Pirate Treasure Hunt (teams acquire staff members and battle the Ice Pirates)
Fall 2013 - An Infinitely Improbable Puzzle Hunt (Hitchhiker's Guide themed, teams must save the Earth from becoming an inter-galactic highway)
Spring 2014 - Zombies
Fall 2014 - Bird Hunt
Spring 2015 - Space
For a great example: A Maze of Twisty Passages (KGB Puzzle Hunt)
Puzzle Hunt wiki: http://wiki.puzzlehunt.club.cc.cmu.edu/