The Global Game Jam® (GGJ) is the world's largest game jam event (game
 creation) taking place around the world at physical locations. Think of it as a hackathon focused on game development. It is all condensed into a 48 hour development cycle. The GGJ encourages people with all kinds of backgrounds to participate and contribute to this global spread of game development and creativity. The structure of a jam is usually that everyone gathers on Friday late afternoon, watches a short video keynote with advice from leading game developers, and then a secret theme is announced. All sites worldwide are then challenged to make games based on that same theme, with games to be completed by Sunday afternoon.