Rough summary of German laws: You have a right to defend yourself with the minimal force necessary to counter a threat to your safety. What a threat is and wha

Rough summary of German laws: You have a right to defend yourself with the minimal force necessary to counter a threat to your safety. What a threat is and what "minimal force" is depends on the knowledge of a defendant: If you know martial arts or medicine you are held accountable for the results of your "self defense" according to much stricter standards than somebody who does not. Same for the evaluation of a threat: If you are trained in threat evaluation, you are expected to be much more level-headed in dangerous situations.