The Checklist for Investigating Mechanisms in Behavior-change Research (CLIMBR) is a standardized guide to help you to conduct, report, and evaluate mechanism-focused research. It is designed to help researchers understand which mechanisms can be influenced through intervention and which mechanisms yield behavior change. CLIMBR is for many kinds of researchers, including, basic scientists who run controlled experiments involving manipulations in lab settings, observational or epidemiological researchers who study associations between mechanisms and behaviors, and translational or applied researchers who develop and test interventions using large-scale trials in hospital or community settings. CLIMBR is a powerful, standardized guide that uses a common method to enable the accumulation of behavioral science findings in a transparent and systematic way.