Matt Weise came to our prototyping group asking us to come up with ideas for a game he wants to develop. A game about ...? Zombies of course.
The main idea: you define a set of behaviours for zombies. You define a set of behaviours from humans. You drop humans and zombies in a virtual town. Hopefully interesting and believable interactions emerge between humans and zombies.
Zombies are easy to figure out. Humans, not so much. The zombie setting serves to drastically limit the range of possible human behaviours that we need to consider (no one takes time to work out, play piano, go to the museum, walk in the park, etc... in a zombie apocalypse). What's left are relationships between people (A loves B, so he will do stupid things to try and save B), information about your surroundings(there's a safe house over there? I'm going to tell my friends and we'll go hole up in there!), and information about what you can do (If I put gasoline, bacon grease, and motor oil in this bottle, stick an oily rag in it, call it a molotov cocktail, light it, and chuck it, zombies die? Sweet! I'm going to tell my friends!)
The challenge is defining a manageable set relationships and information that characters can have, and then model the spread of information from human to human and a believable set of behaviors that stem from relationships between humans. We'll see what we come up with.