This document provides guidance on developing messages about what people should do during earthquake shaking to protect themselves from injury or death. The document refers to this behavior as protective action. The guidance is not designed to advocate one protective action over another. Rather, it describes a process to use and key considerations for creating effective protective actions messages that serve different contexts. This document focuses on actions to take during an earthquake, because information on what to do before and after is available elsewhere and generally better agreed upon. In contrast, messaging agencies around the world advocate a variety of different protective actions. Messages for what to do during earthquake shaking form one part of a broader earthquake safety messaging campaign, as Figure 1 shows. Protective actions messages must complement mitigation and preparedness efforts that will make people much safer from earthquakes in the long term. This document is the result of the project “Guidance on Developing Messages for Protective Actions to Take during Earthquake Shaking” funded by USAID/OFDA. There is no single perfect protective action message, for any nation, or for any jurisdiction. Jurisdictions have different customs, beliefs, buildings, geology, and capacities, and therefore different messaging needs. It is absolutely essential that people understand their specific circumstances and situations and make decisions based on that understanding.