This lecture covers the concept of strategic bidding in power systems, where generating companies aim to increase profits by bidding strategically. It explores the impact of market imperfections, game theory in optimal bidding strategies, and the assessment of market power using the Herfindhal-Hirshman Index. The lecture also delves into energy contracts, market mechanisms, and the use of Game Theory to analyze bidding strategies. Various solution methods of Game Theory are discussed, including the Nash equilibrium and the optimum of Pareto. The lecture concludes with a comparison of pool and bilateral trading in the context of power system restructuring and deregulation.