Some genius named Sam Harris got together Steven Graff Levine (former California DA and now a defense attorny), Rory Miller (former National Guard, 14 year prison guard, 18 months in Iraq advising the prison system, modern and classical martial arts), Matt Thorton (BJJ and MMA coach), to talk about what really qualifies as self-defense under the law, when it is legal to defend yourself, and when it is not.
One of the big take-aways should be that if you are in a situation that escalates into a fight, and then you do something causing serious damage or death, it wasn't self-defense, it was a crime.
This is really should be required reading for anyone who carries a weapon (knife, club or firearm) or who trains in martial arts. Don't fool yourself about what qualifies as self-defense. You might just fool yourself into prison.