infinite two-player games of perfect information have been studied by set theorists and topologists since the 1930's, and the axiom of determinacy plays an important role in modern descriptive set theory. a subclass of these games have turned out to be of great significance in theoretical computer science. work on this line proceeds by reducing the problem of designing a system to work successfully in uncertain environments to the synthesis of winning strategies in appropriately designed in infinite games. determinacy also relates to complementation of automata on infinite trees. these lectures hope to provide a short introduction to this area of research.