The present double issue contains selected papers from the 9th Conference on Logic and the Foundations of Game and Decision Theory (LOFT 2010) that took place on 5–7 July in Toulouse, France. LOFT 2010 was the ninth in a series of conferences on the applications of logical methods to foundational issues in the theory of individual and interactive decision-making. The papers that were presented brought together the work and problems of several fields, such as game and decision theory, logic, computer science and artificial intelligence, philosophy, cognitive psychology, mathematics and mind sciences.