Economic players must often choose between several strategic options in a fierce competitive environment where interactions with competitors make decisions particularly complex. Game theory offers useful insights to choose an optimal decision or at least a basis for making rational decision given the constraints of the stakeholders' environment. In presenting the concepts and the logical structure of the reasoning offered by game theory and their applications, the book explains the rational process of decision making in the framework of firm management and market competition. By avoiding the usual complexity of presentation often due to mathematical formalism, the book proposes a reflection and practical insights of game theory for practitioners (managers, strategists) and social, managerial and economic researchers. The book will expose both general teachings and a comprehensive analysis applied to specific case studies of various sectors of the economy.