For 'prisoner's dilemma', substitute 'N-person prisoners' dilemma' and see how the terrain looks. In appropriate places of course. But also, on a more optimistic note, beware over use of the PD model. (Edited to add link)
Huh, maybe we should hold a tournament for iterated multi-person PD rules. The most interesting paper I found was this one and it just scratches the surface. Do you know if anyone's already done it?
It seems like cooperation should still work well, but I'm not sure how well different enforcement mechanisms would work, which might lead to a sizeable niche for defectors.
This is prompted by Scott's excellent article, Meditations on Moloch.
I might caricature (grossly unfairly) his post like this: