This is a chapter from Jim Ratliff's Graduate-Level Game-Theory
Course. See outline for the entire course. I no longer maintain,
update, or correct these notes. However, I would appreciate
hearing from people who download these notes and find them
useful. Also I may eventually post problem sets and their
solutions. Let me know if you'd like to be notified of such
changes. (Please email me.) (1.0MB; 28 pages) We define a
strategy for a player in an extensive-form game as a
specification for each of her information sets of the (pure or
mixed) action she would take at that information set. One such
strategy for each player constitutes a strategy profile for the
extensive-form game. Every extensive-form game can be expressed
as a strategic-form game. We incorporate uncertain exogenous
events into the extensive form by introducing Nature as a
nonstrategic player who acts randomly. We learn how to construct
the strategic-form of an extensive-form game when Nature takes a
turn at bat. We study two different types of