The present research addresses whether narcissists are more overconfident than others and whether this overconfidence leads to deficits in decision making. In Study 1, narcissism predicted overconfidence. This was attributable to narcissists' greater confidence despite no greater accuracy. In Study 2, participants were offered fair bets on their answers. Narcissists lost significantly more points in this betting task than nonnarcissists, due both to their greater overconfidence and greater willingness to bet. Finally, in Study 3, narcissists' predictions of future performance were based on performance expectations rather than actual performance. This research extends the literature on betting on knowledge to the important personality dimension of narcissism. key words risk taking; overconfidence; decision making; narcissism; personality; adults Individual differences matter in decision making. Gigerenzer and Hoffrage (1995), among many others, have pointed out that average decision strategies can be misleading, as they may reflect decision strategies that no single decision-maker employs. It is often better to explore the decisions that individuals reach. Furthermore, reliable differences in which kinds of people make which kind of decisions are important. Stanovich and West (2000), for example, have defended the reality of various cognitive illusions by demonstrating that people who violate conventionally defined norms tend to be those who perform less well in other domains. Looking at the same base of data, Funder (2000) argued that the observed correlation constitutes standard validation of the test items, and that the ability of some people to solve the problems correctly indicates an absence of systematic irrationality. Beyond theoretical concerns, there are also clear practical applications of such findings, as, for example, organizations could use individual differences measures to avoid hiring individuals who are more likely to be error-prone, when hiring for important decision-making positions. In this paper, we examine how the well-validated personality construct of narcissism is predictive of confidence, risk taking, and performance on a task in which confidence and risk taking are central parts. Approaching these questions is facilitated by the recent reinvigoration of decision-making research using bets that are based on confidence in knowledge (e.g