| Here is the answer for a typical state in the United States. In a civil suit, a punch in the face typically results in a claim of battery (among other possibilities, such as assault). A battery is an “intentional tort” where a person intentionally causes a harmful or offensive contact with another person. One defense to an intentional tort like battery is “self defense.” It varies from state to state, but generally a person may use reasonable force to defend against an offensive contact that he or she reasonably believes is about to happen, but the defense must be proportional. So in your scenario, person A sues B for assault. If person A admits that he was the initial aggressor and the response was reasonable and proportional, the case may well be dismissed. If they do not directly admit it but the facts show they do admit show that the response was proportional as a matter of law, the case will also be dismissed. If not, the case will continue to summary judgment. If, after discovery, no reasonable juror could find that the response was not reasonable and proportional (i.e., there is no genuine dispute of fact), then the court will find for person B. But if a reasonable juror could find that the response was not reasonable and proportional, the case will continue to trial. (Both dismissal and summary judgment will only happen if person B moves for relief, but that almost always happens) Obviously, person A’s attorney is going to know these rules going in, and they are going to do their best to portray the facts in a way that the claim will survive motions to dismiss and for summary judgment and make it to trial. Once you make it to trial, anything can happen, because it is in the hands of the jurors. After the jurors render a verdict, the court will review that verdict to determine again if the prevailing party presented sufficient evidence for a reasonable juror to find in their favor. The court will also evaluate whether any errors occurred in the trial that warrant a new trial. Then the losing party has an opportunity to appeal those and other rulings of the court. |