The article is a guide on how auctions work, using game theory to understand and predict outcomes. Auctions are like negotiations with strict rules, making them perfect for game theory analysis. The key findings include the revenue equivalence theorem, the winner's curse, and how to design optimal auctions. The article also covers practical aspects like collusion, competition, and information disclosure in auctions. It discusses real-world examples like energy and telecommunications auctions, which help test new auction designs. This guide is helpful for students, researchers, and practitioners looking to understand and improve auction strategies.