Dueling with swords, until first blood, ought to be leagal. Not to decide guilt, but as a way of settling slights. Of course I fence, so I’m slightly biased.
Of course, I'm a brown belt in Brazilian Jiu Jitsu, so I'm slightly biased.
I took a few short-sword lessons a while ago. The First thing we were taught was a simple block, the second thing was how to defeat a simple block by twisting your blade into the other guy's neck. The third thing was how not to get stabbed in the neck that way. It went back and forth from there.
I suspect a good cut to the neck would be the most common wound, and it would have a good chance of being a mortal one.