What Is an Alternate Reality Game?

An a r g is an interactive, net worked narrative that uses the real world as a platform. Some common examples of this type of game include viral marketing stunts expanding the story worlds of existing i ps and movies. What if there was a different kind of game? Something darker, more mysterious, something that wasn't tied to a film or television property, video game or movie? That's one thing that an alternate reality game can do. But what if there are other things, less positive things, more dangerous results?