We conceptualize broad purges, which extend far below top powerholders in authoritarian regimes and operate according to a logic fundamentally different from coup-proofing purges that target rivals to the supreme leader. Broad purges induce risk reduction in decision making because they grossly exacerbate uncertainty and raise the likelihood and cost of political error. Empirically, we analyze political appointment decisions before and during a massive corruption crackdown in China. We estimate purge impact on appointments of prefectural Communist Party secretaries during 2013–17. To signal to Beijing that they are not building factions, party bosses of these officials can be expected to reduce risk by biasing appointments against their own clients, with variation in bias reflecting geographic heterogeneity in purge intensity. We find a large effect of purge intensity on anti-client bias during this broad purge but not in previous smaller-scale anticorruption crackdowns. This study contributes to knowledge about purges under authoritarianism.