  Negotiations, a model of concurrency with multi party negotiation as
primitive, have been recently introduced in arXiv:1307.2145, arXiv:1403.4958.
We initiate the study of games for this model. We study coalition problems: can
a given coalition of agents force that a negotiation terminates (resp. block
the negotiation so that it goes on forever)?; can the coalition force a given
outcome of the negotiation? We show that for arbitrary negotiations the
problems are EXPTIME-complete. Then we show that for sound and deterministic or
even weakly deterministic negotiations the problems can be solved in PTIME.
Notice that the input of the problems is a negotiation, which can be
exponentially more compact than its state space.

Logic in Computer Science