When someone is injured during a sports activity, the one who caused the injury will likely raise a defense called "assumption of risk". The wrongdoer argues that he’s not to blame because the law didn’t require him to protect the participant from the particular risk of harm involved in the claim. Whether the doctrine applies to protect the wrongdoer depends on two factors: 1) the nature of the sport, and 2) the relationship between the parties.

For example, a golfer who suffers a brain injury when struck in the head by a sliced golf shot on the course would likely be barred from making a claim against the golf course or the golfer who made the bad shot. The risk of getting hit by a ball is inherent to the sport of golf and so the golfer, by participating in the sport, “assumed the risk”.