We analyse the computational complexity of finding Nash equilibria in stochastic multiplayer games with $\omega$-regular objectives. While the existence of an equilibrium whose payoff falls into a certain interval may be undecidable, we single out several decidable restrictions of the problem. First, restricting the search space to stationary, or pure stationary, equilibria results in problems that are typically contained in PSPACE and NP, respectively. Second, we show that the existence of an equilibrium with a binary payoff (i.e. an equilibrium where each player either wins or loses with probability 1) is decidable. We also establish that the existence of a Nash equilibrium with a certain binary payoff entails the existence of an equilibrium with the same payoff in pure, finite-state strategies.

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Springer
E. Grädel (Erich) , R. Kahle
Lecture Notes in Computer Science
Distributed Implementations of Adaptive Collective Decision Making
International Conference on Computer Science Logic
Networks and Optimization

Ummels, M., & Wojtczak, D. (2009). Decision Problems for Nash Equilibria in Stochastic Games. In E. Grädel & R. Kahle (Eds.), Proceedings of Computer Science Logic 2009 (18). Springer.