In an earlier post, I discussed medieval violence. There was certainly plenty of violence then (as now!), but there were also plenty of ways to defuse conflicts before they became violent.
It used to be thought that, in an era without the courthouses, police forces, and clear law codes we take for granted now, then anarchy was the only possibility. This was far from the case in the Middle Ages, in large part because everybody agreed on (or at least gave lip service to) the ideal of peace.
If two men (say, in a drunken brawl) leaped at each other, their friends were supposed to grab them and pull them back, not egg them on. Hot-headed violence was deplored in all the epics and romances, not celebrated. (Our own movies and TV shows glorify violence a lot more than did medieval literature.) Local authorities, whether landlord, sheriff, count, or even king, were expected to act as peacemakers.
A quarrel would be brought before a court, not anything like our judicial courts, but the court of a powerful man (or sometimes woman). Both sides would present their positions. Long discussion would ensue. Both sides would bring forth witnesses, oath-helpers, and material evidence. More discussion would ensue. The judge would not end up ruling definitively for one or the other, but rather act more as a mediator, trying to reach some sort of agreement. The only way one party would get a summary judgment against them would be if they failed to show up.
Sometimes one party or the other would volunteer to undergo trial by ordeal. The other side, realizing no one would volunteer to do something so painful unless completely convinced they were right, would often yield at this point, leaving the other side the winner. If someone were accused of major crimes, and everyone knew they were guilty, a good defense would be to suddenly become penitent and head off to Rome or Jerusalem on pilgrimage. By the time one came back, with luck things would have blown over.
If one had a quarrel with a church, or even a quarrel that involved such sacraments as marriage or oaths, one side or the other could stop the proceedings cold by appealing to the pope, from the early twelfth century on. Both sides would then go to Rome, get in line to await judgment (a line often years long), and usually end up settling it between themselves anyway. (By the later Middle Ages, popes started just referring most cases back to the local bishops, so appealing to Rome was much less useful.)
Churches would try to forestall quarrels over pious donations by getting all relatives of the donor to agree ahead of time. This was much easier than the alternative, trying to persuade one's saints to blast the malefactors. Threats of such saintly blasting, however, could be quite persuasive.
Castles also acted, by their very presence, to forestall violence. Although one now thinks of castles as centers of fighting, most would not be attacked for centuries. Their very presence sent a clear message, Don't even think of it.