A growing body of research suggests that authoritarian regimes may gain international legitimacy when they undertake reforms. According to several studies, for example, Saudi Arabia and Jordan promote women’s empowerment in part to signal modernity and Western-friendliness to international audiences, potentially obviating the need to undertake deeper political reform (e.g., Al-Rasheed 2013; Bush 2019; Tripp 2019). To date, however, these hypotheses have not been tested experimentally. This paper helps fill the gap by presenting results from an iterative series of experiments conducted over nationally representative samples of US citizens, asking respondents to evaluate hypothetical and actual authoritarian regimes in the Middle East under differing circumstances while assessing a suite of different potential policies toward them. Results consistently suggest that reforms (of a variety of types) do generally enhance legitimacy, yet also provide support for several new and previously undocumented findings: (1) it may be easier for authoritarian regimes to obtain positive “boosts” in legitimacy (such as higher favorability ratings and support for positive actions, e.g. increased trade) than it is for them to “shield” themselves from punitive actions (e.g., boycotts and cutting off relations); (2) inward-facing and prodemocratic reforms, especially liberal initiatives like enhancing women’s rights and autonomy, produce the strongest “boosting” benefits in terms of favorability and positive actions; (3) more outward-facing reforms that stress benefits and contributions to global welfare, such as commitments to scientific advances or reductions in carbon emissions, produce the strongest “shielding” benefits; and (4) monarchies undertaking reforms gain fewer “boosting” benefits, compared to military dictatorships, due to high baseline levels of support, while demonstrating greater resilience to skeptical responses about their reforms.