So, I've always been a fan of the medieval ages and chivalry and honor and all that good stuff, and recently as I was thinking about it, it got me wondering. Is it possible to have a duel to the death set up in a way where neither party receives any negative legal backlash (i.e. being labelled a murderer and tried as such)? I know back in the time of the civil war it was still legal (at least I believe it was) to have a death duel, but of course we also could have slaves so the laws have changed a lot since then. But is it possible now, maybe with a contract of some sort to ensure that both parties knew what they were getting themselves into, to legalize a duel to the death?
Jimsung and Dale's answers address the enforceability of the contract (i.e. the contract is unenforceable and has no value). For criminal liability, there's another issue in play: whether a crime committed with the consent of the victim is a crime. For some crimes, it is not; consensual rape is simply not rape, because a key element of rape is lack of consent. For crimes where consent is not an element, things can get somewhat complex, but one of the basic common-law rules is that no one can consent to be murdered. This is changing a little bit in some places to deal with assisted suicide, but the laws being passed in those jurisdictions are restricted to assisted suicide, and wouldn't apply to duels.
I stumbled across this question and I think I might have a reasonable answer not yet proposed.
If with absolute certainly you believe that another individual intends to do you harm then you have a constitutional right to self defense. If they intend to kill you, you can use lethal force to protect yourself.
It might be possible to argue that you were mutually engaging in the act of self defense. "If I didn't shoot, he would have shot me." This would also hypothetically apply anywhere. Though only some state have a stand your ground clause. In some you have a responsibility to retreat when possible.
UK-based answer here.
It is in theory possible for two clinically insane (who are incapable of appreciating that what they were doing was wrong) people to duel eachother and the survivor wouldnt be guilty of murder by reason of insanity.
It is also possible for two people to murder eachothers wives (or any sort of "qualifying trigger"), and enrage eachother to the point that the "loss of control" defence applies. This only applies when a qualifying trigger occurs and when the jury finds that reasonable men would have acted in the same way.
For example: two men murder eachothers wives, this causes both of them to be so enraged (at the fact that their wives were murdered, thus being a qualified trigger) that they try to kill eachother (the extent to which this is an act that reasonable people would have also done is a question to the jury). They would be guilty of voluntary manslaughter but not murder (well theyd be guilty for the murder of eachothers wives, but not of eachother)
The term "contract" does not apply here. The concept of a "contract" refers to two parties mutually obligating each other for mutual benefit. Simply granting consent is not a contract. So @jimsug 's claim that "One of the conditions for a contract to be enforceable is that its undertakings must be legal." is largely moot, as there is nothing to enforce. Another issue is that the law treats criminal trials as being actions by the state against the defendant (notice that it's "The People vs. ...", not "[The victim] vs. ..."). Since the state is not a party to this agreement, the agreement does not affect their actions. If you could get the state to consent to the duel, that would be another matter entirely. As for whether you could get immunity from a civil suit, that is more complicated.
Of course, if you were to leave the jurisdiction of your country, say by sailing to international waters, then it would be difficult for the country to prosecute you (although they may have some grounds on which to assert the right to prosecute, such as claiming that it qualifies as piracy).
I'm speaking from the American law perspective here, but the real question isn't what the law says you can do, it's what happens if and when the would-be murderer ends up in a courtroom. If it's a criminal trial, as soon as you hold up your contract, the judge will ask you where the state or federal government signed.
That's because when you commit a crime, you're not just committing it against people, you're committing it against the State. Why do you think it's possible to be convicted for using illicit drugs, when you yourself may have been the only person affected?
As far as the State is concerned, your contract may prevent the loser from pressing charges, but it certainly poses no such restrictions on government prosecutors, and it likely wouldn't even stop the loser's charges. You might notice many contracts have severability clauses, saying essentially that if any part of the contract is found to be unenforceable, the rest still applies. This is necessary because you very specifically cannot have a contract between private parties enforce an exception to the law for the very reason specified above: it's not your law to change, it's the government's.
A similar situation would be if an employer asked an employee to sign away their right to a minimum wage. While this is slightly different because there is language written into federal labor laws specifically for the purpose of preventing waiving these rights, the underlying principle is the same: you can't create exceptions to laws with only contracts between private parties.
If you really want to see the return of duels to-the-death, I'd suggest you talk to your president.
I've been researching duals and from what I gather it is legal in most states the problem lies with manslaughter and aggravated assault. Mutual combat is essentially what a dual is. And if you look that up there are cases where people where not charged and others convicted of manslaughter. So the rule/law states both parties must enter mutually with witnesses stating as such Neither party can use excessive force I.e. party A uses a knife party B uses a gun. The most important part is the losers witnesses must agree with the winners witnesses both parties used equal force and any death was a result of mutual combat But remember in every state has wrongfull death laws. And federal law along with states law agree manslaughter is the accidental or unintentional death caused by one person to another. And you do not need a victim for manslaughter the prosecution has the right to act as the victim. Same goes for aggravated assault and domestic violence which if your dual doesn't end in death both parties would be charged with even if a written contract signed by both parties. The prosecution can choose to ignore the contract given the victim is not alive to validate the contract themselves. Then you add with the way things are now a days if you get into a fight let's say with your best friend fights over your both sitting on the porch having a beer crying saying your sorry ( if any of you have faught a real friend you know that's how it normally ends if your truly best friends anyway) neighbor called the cops. The law shows up. Now even though the fight is over nobody needs medical attention your both more than likely going to jail. Charges ranging for disturbing the peace, domestic violence and assault if not aggravated assault. Afterwards even if neither of you wanted to press charges it's now not up to you but the prosecution. Even if you go to court and defend each other you will be found guilty of at minimum of domestic violence.