In order to investigate the use of strategies in a game-playing computer program, "Gammon," a computer program that plays Backgammon, was developed. It focuses on the play of a given strategy, as well as the process of strategy selection, and examines the concept of strategy as an integrating and driving force in the play of a game. A "strategy" is defined and implemented as a set of tactics where each tactic is a specific feature of play. Moves are generated and evaluated on the basis of the degree to which they accomplish the objectives of the tactics making up the current strategy. Strategies are selected and changed during the course of a game by heuristic analysis of the current game situation. Deductive learning mechanisms are employed to improve the program's performance against both human and machine opponents. In general, the validity of the strategy concept developed for Gammon was verified by the performance of the program. The strategy concept was satisfactory in terms of the long-range or overall character of the play, but inadequate with respect to recognizing and exploiting critical short-range (existent over the span of a few moves) objectives. A list of Gammon tactics, a sample strategy set, a description of the program's modules, and a sample computer game are included. (Author/MT)