At it's core,it's really a story-hook generator. There's a pool of dice the players (there's no GM) use in combination with a set of lists to generate places, relationships, motivations, etc. And not just their own; during the prep, you can set aspects of other people's characters, too.
For example, in the game I played, one of the other players tagged me and the guy to my right as having a relationship of "think they are related but really aren't", and another player tagged the motivation "wants to get it on with a freaky Mexican" between us, as well. Having been previously tagged as an "OSHA inspector" and the other player as a "local cop", I decided that I was Carmen Esperanza, who claimed to be his distant cousin from Mexico and that I'd used that to persuade him to get me a job inspecting the local ethanol plant (which was a front for a crystal meth lab that two of the other players were running).
Players take turns framing a scene between one or more of the other characters, any NPCs they want, and then roleplay it. The other players then decide whether it turns out good or bad for the acting player. Or, if the player wants, they can let the others decide the scene, and then the player decides the outcome.
It's split into two 'acts', and there's another smaller round to generate some new story elements between the two. And the scene resolution mechanic changes slightly in the second act, as well. Then there's a round after the second act where the fates of the characters are decided.
