Although empirical research has generally demonstrated that democracies experience more terrorism than autocracies, research suggests that this depends upon complex institutional differences that go beyond the democracy-autocracy divide. This study examines these differences, linking institutions to strategies of coercion and co-optation. Using zero-inflated negative binomial regression estimations on Geddes ' (2003) autocratic regime-type data for 161 countries between 1970 and 2006, we find that single-party authoritarian regimes consistently experience less domestic and international terrorism relative to military autocracies and democracies. This finding is robust to a large number of specifications, underscoring the explanatory power of regime type for predicting terrorism. Our explanation for these findings is that party-based autocracies have a wider range of coercion and co-option strategies that they can employ to address grievance and dissent than do other, more strategically restricted, regimes.T he literature on terrorism considers regime type to be an important factor determining which countries experience higher levels of terrorist attacks. The overwhelming bulk of studies fixate on the relationship between democracy and terrorism, arguing that democratic institutions that provide for policy concessions and tolerate political opposition activity make terrorism more likely. Indeed, most empirical studies published in the past 15 years find that democratic regimes are more likely to contain terrorist movements and experience terrorist attacks (Blomberg and Rosendorff