Abstract
Bayesian games offer a suitable framework for
games where the utility degrees are additive. This
approach does nevertheless not apply to ordinal
games, where the utility degrees do not capture
more than a ranking, nor to situations of a decision
under qualitative uncertainty. This paper proposes a
representation framework for ordinal games under
possibilistic incomplete information and extends
the fundamental notion of Nash equilibrium (NE)
to this framework. We show that deciding whether
a NE exists is a difficult problem (NP-hard) and
propose a Mixed Integer Linear Programming encoding. Experiments on variants of the GAMUT
problems confirm the feasibility of this approach.