Robert Mach

We investigate the adaptation of cooperating strategies in an iterated Prisoner's Dilemma (IPD) game. The deter-ministic IPD describes the interaction of N agents spatially distributed on a lattice, which are assumed to only interact with their four neighbors, hence, local congurations are of great importance. Particular interest is in the spatial-temporal distributions of agents playing dierent strategies, and their dependence on the number of consecutive encoun-ters ng during each generation. We show that above a crit-ical ng, there is no coexistence between agents playing dif-ferent strategies, while below the critical ng coexistence is found. 1