  In the literature of game theory, the information sets of extensive form
games have different interpretations, which may lead to confusions and
paradoxical cases. We argue that the problem lies in the mix-up of two
interpretations of the extensive form game structures: game rules or game runs
which do not always coincide. In this paper, we try to separate and connect
these two views by proposing a dynamic epistemic framework in which we can
compute the runs step by step from the game rules plus the given assumptions of
the players. We propose a modal logic to describe players' knowledge and its
change during the plays, and provide a complete axiomatization. We also show
that, under certain conditions, the mix-up of the rules and the runs is not
harmful due to the structural similarity of the two.
