From the introduction:
The Carcass: Exodus is a roleplaying story game about the end of the world. There are a lot of roleplaying games about the end of the world, and most focus largely on conflict: fighting off marauder bands, defeating warlords and the like.
But what if they weren’t all like that? What if one of them was about rebuilding the community?
That’s the premise which makes The Carcass: Exodus unique: addressing aspects of a post-apocalyptic environment that don’t embrace the obvious clichés.
Firstly, as with the other games in the GMZero series, this game can be played with or without a gamemaster. The rules don’t really change; only the person in charge of the action does.
Secondly, the characters are not adventurers or saviors. They are real people trying to survive and rebuild in a world ravage by the past. What makes The Carcass: Exodus unique is that the past is different every time you play. So is the world. The players determine the nature of the environment and the goals their characters need to meet over the course of play.
The people living in the world of The Carcass: Exodus lack a coherent understanding of the past and what has led to now. In addition, this new edition of the game introduces pre-made histories and worlds for players (or gamemasters) who want to know more going in.