Knowledge and Lotteries is organized around an epistemological puzzle: in many cases, we are inclined to deny that we know a certain proposition, despite having credited ourselves with knowledge of various propositions which straightforwardly imply it. In its starkest form, the puzzle is this: we do not think we know that a given lottery ticket will be a loser, yet we normally count ourselves as knowing all sorts of ordinary things which entail that its holder will not suddenly acquire a large fortune. After providing a number of specific and general characterizations of the puzzle, Hawthorne carefully examines the competing merits of candidate solutions. In so doing, he explores a number of central issues concerning the nature and importance of knowledge, including the relationship of knowledge to assertion and practical reasoning, the status of epistemic closure principles, the merits of various brands of scepticism, the prospects for a contextualist account of knowledge, and the potential for other sorts of salience-sensitive accounts. Along the way, he offers a careful treatment of pertinent topics at the foundations of semantics. His book will be of interest to anyone working in the field of epistemology, as well as to philosophers of language.