Assumption of risk means a plaintiff willingly engaged in the activity that harmed them despite knowing there was a potential risk of harm to them. Express Assumption of Risk.This is when the plaintiff explicitly agrees, often in writing, to assume the risk of a particular activity. How to fill out the Assumption of Risk Waiver and Release Agreement? 1. Read through the entire document carefully. 2. Assumption of risk is a legal doctrine that recognizes an individual's freedom to accept certain risks voluntarily.