<p>Deceiving participants is an ethically complicated research practice which remains an important challenge for research ethics committees (RECs) and researchers, despite the availability of abundant research ethics guidance. Exploring this persistent policy-practice divide, we develop a framework for assessing the needs of the REC review of deceptive studies in a context-sensitive way. Different guidance formats are evaluated in light of their potential contribution to the frequently recurring REC review need for consistent and representative rules that set a perimeter for precise, coherent and representative discretionary review to take place. Research ethics guidelines and a new format of “descriptive living documents” are argued to respectively provide perimeter-setting rules and support discretionary decision-making about the justifiability of deceptive studies. REC review coordination is argued to benefit from analogous guidance formats to ensure conditions that facilitate successful REC review. As the needs of REC review may differ depending on the context, different mixes of these and possibly other guidance formats may support the REC review of deceptive studies and offer a way out of the policy-practice divide.</p>