 The move from perfect to imperfect information has major implications for strategic reasoning. In the game depicted above, player A cannot distinguish between being at m and \(m'\). When at the former, she may, for all she knows, be at \(m'\) instead. Hence A’s decision needs to account for both possibilities; she cannot base her choice on any property that holds at only of those locations. In particular, A has no available strategy that guarantees her ending up in a \(\win_A\) node. Since E cannot ensure a win either, no player has a winning strategy. This is a central difference with finite perfect information games, where it is guaranteed that one of the players has a winning strategy, cf.  Section 2.4.