Game calibration helps prevent harm and establish expectations. I recommend players and runners fill out the form on their own, then have a frank discussion about their responses as a group. This is designed primarily for smaller player groups, not large scale events. It's one page, and by no means comprehensive, but designed to be a conversation starter. This page has a link to the Google Doc version. Feel free to make your own copy and edit it for your games. No credit/attribution needed.