As we noted in Section 1.3, there are different stages to the decision making process. Differences between these stages become even more pronounced in extensive games in which there is a temporal dimension to the game. There are two ways to think about the decision making process in an extensive game (with imperfect information). The first is to focus on the initial “planning stage”. That is, initially, the players settle on a strategy specifying the (possibly random) move they will make at each of their choice nodes (this is the players’ global strategy). Then, the players start making their respective moves (following the strategies which they have committed to without reconsidering their options at each choice node). Alternatively, we can assume that the players make “local judgements” at each of their choice nodes, always choosing the best option given the information that is currently available to them. A well-known theorem of Kuhn (1953) shows that if players have perfect recall, then a strategy is globally optimal if, and only if, it is locally optimal (see Brandenburger 2007 for a self-contained presentation of this classic result). That is, both ways of thinking about the decision making process in extensive games (with imperfect information) lead to the same recommendations/predictions.