Communication complexity of approximate Nash equilibria

Yakov Babichenko, Aviad Rubinstein

For a constant εε, we prove a poly(N) lower bound on the (randomized) communication complexity of εε-Nash equilibrium in two-player NxN games. For n-player binary-action games we prove an exp(n) lower bound for the (randomized) communication complexity of (ε,ε)(ε,ε)-weak approximate Nash equilibrium, which is a profile of mixed actions such that at least (1−ε)(1-ε)-fraction of the players are εε-best replying.