This document discusses alternate reality games (ARGs). ARGs tell transmedia stories across multiple platforms to engage users in helping to progress the narrative. Two major ARGs are discussed: Why So Serious?, which promoted The Dark Knight and involved puzzles solved by fans online and at events; and Year Zero, which supplemented the Nine Inch Nails album of the same name and hid clues on USB drives left at concerts for fans to uncover online. ARGs expand stories across television, websites, print ads and more to immerse users in helping to solve puzzles and advance alternative realities.