I posted this over in a GD thread on hazing. Not sure whether it is correct, because I’m a lawyer of very limited skill, and was a downright crappy law student.
To what extent could the state prosecute absent a complaint by one party against the other?
*Law school is a long time ago, but I seem to recall a distinction between assault and battery. Based solely upon my recollection from classes long ago that I probably didn’t do too well in:
Assault is a realistic threat, that causes the victim to fear harm. Say I’m standing in front of you with my fists clenched, and say “I’m going to beat you up.” Or calling someone names could be a verbal assault. Brandishing a gun or knife could be assault with a deadly weapon.
Battery is an impermissable touching. Hitting someone, breaking their ankle, or smearing them with feces is battery, not an assault.
In very general terms, you may consider the threat to be the assault, the action is the battery.
I also seem to recall from tort class (to distinguish from criminal law) that you are not able to to consent to a battery. Which led to one of the highlights of my law school career.
I asked in class: “What if 2 parties mutually agree to participate in activity that will likely result in mutual injury?”
Teacher asked: “What did you have in mind, Mr. Dinsdale?”
Me: “I was thinking about a little S&M or B&D.”
Teacher: “NEXT!”*
I’m not really sure about why boxing is legal. Probably has to do with specific state regulation. That is why NHB contests have trouble finding venues. And just because voluntary activity might reasonably result in injury does not mean anything goes. I seem to recall instances where football players sued for excessive or late hits. No cite handy, tho I may look one up later.
I did some legal research related to MA a while back. There are many instances where instructors were held responsible for injuries in their schools. Generally related to negligence. Say, the instructor is demonstrating a technique, and the student ends up being injured. Or the instructor allows students of different skill levels to go at it too hard. I am amazed at the number of folks who teach MA without insurance - often out of their homes.