There is an ongoing debate among organizational scholars as to whether Machiavellianism is a liability for leaders. Some scholars argue that Machiavellian leaders are likely to fail due to their toxic orientation toward followers, while others suggest that Machiavelli's teachings constitute a set of best practices. To balance these perspectives, we blend socioanalytic theory and mimicry-deception theory to argue that risk detection and political behavior are necessary adaptations for leaders but that Machiavellianism is a special case of their manifesting in predatory tendencies. We further argue that these leaders often avoid social sanctions as others know that betrayal is a legitimate risk in business and politics and so resonate with their vision. To test our predictions, we meta-analyzed effects of leader Machiavellianism on 15 criteria across 163 samples and 510,925 participants, supplementing bivariate results with tests of incremental validity and conditional effects involving time, personological moderators, and curvilinearity. Results suggest alarmingly high associations with undesirable leadership styles and follower outcomes, but they also suggest that these leaders' success is conditional, resulting in their being neither rewarded nor penalized on average. We conclude by discussing implications of our conceptual update on leader Machiavellianism for future research.