Self-defense is a legal defense to criminal charges that can be used when a person reasonably believes that they are in danger of being harmed by another person. This can be either in response to an immediate threat or to prevent future harm. In order to claim self-defense, the defendant must usually show that they first attempted to retreat or avoid the confrontation altogether, and that they only used force as a last resort.
There are different types of self-defense depending on the severity of the threatened harm and the corresponding level of force that can be reasonably used in response. In general, however, self-defense claims will fall into one of two categories: justification defenses and excuse defenses.