 Climate change and human activities are causing rapid decline in coral reef health. In vitro experiments have provided valuable insights into how reef organisms might respond to future climates. However, these experiments are limited in their ability to replicate the complex interactions that govern reef systems. Studies looking at coral communities that already exist under natural extreme and marginal physiochemical conditions have become increasingly popular to advance ecosystem scale predictions of future reef form and function. No single site provides a perfect analogue to future reefs, so a synthesis of the available data has been conducted to increase understanding of the biological and ecological mechanisms that enable survival and success under suboptimal physical chemical conditions. This comprehensive assessment can help identify the extent of extreme abiotic scenarios under which corals can persist, identify commonalities among coral taxa able to persist in such extremes, explore the key mechanisms required to support survival and or persistence under suboptimal environmental conditions, and evaluate the potential of current suboptimal coral environments to act as potential refugia under changing environmental conditions. Priority areas for future research on extreme and marginal. This article was authored by Emma F. Camp, Verena Shope, Peter J. Mumby, and others. We are article.tv, links in the description below.