During a pandemic, the government requires active compliance by citizens. While these demands can be enforced with rewards and punishments, legitimacy allows the government to achieve the same results with greater cost effectiveness. The way in which a government can acquire substantive legitimacy depends on how it communicates and justifies its decisions. In this article, we measure revealed legitimacy, via approval of three potential mitigation strategies against Covid19, when they are defended using expert endorsement, consultation by civil society, and mediation between opposing interests. Our methodological choice was to randomly assign participants to either a non-conflicting priming or to one that emphasizes the risks involved, (e.g. connection between health and economy, uncertainty, and economic costs). The data come from an online experiment we conducted as part of a longitudinal study in several countries. The countries included are Italy, Spain, and the United Kingdom. The results show that the support of experts in non-controversial domains is preferred (consensus of value, low uncertainty, diffuse rents). Contrary to our hypotheses, we found that citizen deliberation is not preferred under high epistemic uncertainty, and mediation is either indifferent or not preferred under conflict of value and conflict of interest.