Candidates often make ambiguous statements about the policies they intend to pursue. In theory, ambiguity affects how voters make choices and who wins elections. In practice, measurement and endogeneity problems have impeded empirical research about the consequences of ambiguity. We conducted survey experiments that overcame these obstacles by manipulating a common form of ambiguity: the imprecision of candidate positions. Our data show that, on average, ambiguity does not repel and may, in fact, attract voters. In nonpartisan settings, voters who have neutral or positive attitudes toward risk, or who feel uncertain about their own policy preferences, tend to embrace ambiguity. In partisan settings, voters respond even more positively to ambiguity; they optimistically perceive the locations of ambiguous candidates from their own party without pessimistically perceiving the locations of vague candidates from the opposition. We further find, through analysis of two additional new data sets, that candidates often take—and voters frequently perceive—ambiguous positions like the ones in our experiments. The pervasive use of ambiguity in campaigns fits with our experimental finding that ambiguity can be a winning strategy, especially in partisan elections.