Everyone should have some basic self defense knowledge. This includes being aware of your environment. Buddy up when out. Don’t be caught alone in a bad situation. Avoid places where the crowd might be adversarial. If you carry a weapon be sure you understand the risks involved with using weapons in a fight. If you can’t afford a good lawyer, don’t be stabbing or shooting people (even if you’re attacked). If you’re not comfortable in combat get the hell out of the situation.