SOPLAY is a direct observation tool for assessing use in free play settings. The tool provides protocols for observers to track users’ physical activity levels, activity types, genders, and estimated age and race/ethnicity groupings during a specified time frame using momentary time sampling. It can also be used to evaluate play area attributes such as accessibility, usability, supervision, and equipment provision. SOPLAY requires direct observation of the area to be evaluated and coding of the results. A full-text user guide, protocols, mapping strategies for the target area, worksheets, training videos, and a recorded webinar are available.