Vijay Krishna's 2e of "Auction Theory" improves upon his 2002 bestseller with a new chapter on package and position auctions as well as end-of-chapter questions and chapter notes. Complete proofs and new material about collusion complement Krishna's ability to reveal the basic facts of each theory in a style that is clear, concise, and easy to follow. With the addition of a solutions manual and other teaching aids, the 2e continues to serve as the doorway to relevant theory for most students doing empirical work on auctions. It focuses on key auction types and serves as the doorway to relevant theory for those doing empirical work on auctions. It includes a new chapter on combinatorial auctions and new analyses of theory-informed applications. It also includes new LaTex Beamer slides, chapter-ending exercises, problems of varying difficulties, and a solutions manual support and reinforce key points.