I should be stating the obvious here, but the fact that I even have to post this means that obviously, I am not.
Just because something is written into the terms of an agreement doesn't make it legal.
Just because something is written into the terms of an agreement doesn't make it legal.
A legal contract depends on mutual understanding. People learning to box generally understand they are going to get hit. People booking a wedding party generally don't expect to be held responsible for their guests having opinions they post online. The hotel would have to make this policy very clear in order to achieve mutual understanding, and that doesn't mean just putting it on the contract and the webpage for the customer to find on their own.
Participation in a contract that specifically covers terms for being slapped also bring with it an expectation of being slapped.
It's not enough to have language in a contract. There needs to be understanding by both sides about what is being agreed to.
Since the Internet engaged mob-mode before engaging investigation-mode, we don't know how clear these terms are to people who are booking weddings.
It might be very clear because they send an email explicitly telling the bridal party about these terms and asking them to consent, which would also be a signal to the party about the quality of online reviews. Or it might be buried in the middle of 12 other clauses and the customer doesn't know about it.
Your contract would be unenforceable btw - I could slap you three times (hell make it twenty) and walk off - you could not get any court to enforce payment. You could threaten to accuse me of assault if I did not pay up - but then you are blackmailing me and would do more time than I would for assault.
But I suspect that the hotel owner has been slapped by a couple of brides over this :-)
But it depends why you're being slapped! Obviously we can't go prosecuting everyone who intentionally whacks into someone else according to the rules of whatever sport they're playing, so we make an exception for that. This gets tricky with sports like boxing where the rules require you to do something that looks pretty much like a brutal assault, so the exceptions in that case get pretty finicky -- we might insist that you make your mutual-battery deals in public, in licensed boxing rings, instead of by giving Brad Pitt a nice manly handshake in the basement of a bar and refusing to talk about it later.
And then there's the whole gray area of less socially-accepted sports, like Quidditch or BDSM. We (even prosecutors) often approach things from the perspective of, "if this activity seems normal to me, it must be legal; if it seems wrong it must be illegal." When moral judgments and fear of the unknown creep into that analysis, it can lead to some twisted logic to justify the outcome we know must be right.
[1] Now consider whether you can be prosecuted for A&B as an accomplice.
Similar pieces of other contracts are valid and common and are called "non-disparagement clauses". I don't see how this differs.