I know I am coming to this very late, but I have to very strongly (but with sincere respect) disagree with parts of SevenSidedDie's answer.
Bottom Line: I think questions about the law that affect RPGs are on topic, but answers on a forum like this might not always be accurate.
I will partially agree with SevenSidedDie about what is arguably the core question. As long as it is in some way related to RPGs, a question that touches on the law is on topic here. Also, non-lawyers can be quite knowledgeable about the law and can give very good answers to questions about legal topics. Further, some of us do happen to be lawyers. I for instance am a Nevada lawyer whose practice includes copyright and trademark matters among other things. In fact, I have a published academic article on a copyright topic. I absolutely without exception refuse to give legal advice on a forum like this and I am very very cautious about providing legal information on a forum like this, but I am still a lawyer on this forum and I suspect there are others here that are perhaps less cautious about discussing legal topics. Because of all of those things, I think questions about legal topics are perfectly permissible here.
With that said, I also think answers about legal topics on a forum like this are not consistently reliable. I have repeatedly seen answers to law-adjacent questions that are oversimplifications to the point of being dangerous. While I rarely see answers that are outright wrong here, they do happen. (And I see statements about the law that are blatantly, absolutely, completely wrong on Facebook all the time. We seem to do a little better than that here.) The closest I will come to giving legal advice on a forum like this is to say that if it actually matters as opposed to satisfying curiosity, it might be wise to consult a qualified attorney in your jurisdiction.
Copyright laws do vary meaningfully from one country to another
SevenSidedDie suggests that copyright laws are widely harmonized due to the Berne Convention. This is arguably true, to a degree. The Berne Convention along with related conventions such as the Universal Copyright Convention do create a standardized framework that most (not all) of the world has adopted regarding Copyright.
However, there are still significant differences in copyright laws between nations. It is semi-common for some older works to be in the public domain in one country while not being in the public domain in another. Some countries such as Canada and France have very strong "moral rights" or "droits moraux". The USA has much weaker recognition of moral rights primarily in VARA.
Also, while most countries have some doctrine similar to Fair Use, that topic can vary significantly between different countries. (While this is debatable and isn't really supposed to happen, some experts will even say that there can be meaningful differences at the margins between the different Federal Appellate Circuits on that topic...)
The fact that jurisdiction can matter is another reason to be very cautious about any answer that does not contain an in-depth analysis of the specific facts including the involved jurisdictions.
Unauthorized practice of law varies by jurisdiction and can be broad
This is a good place to caveat again that nothing in this post or any post I make on this forum should ever be construed as legal advice. While copyright is a meaningful part of my practice, malpractice and criminal issues are not areas I usually practice in.
With that said, I respectfully but strongly disagree with SevenSidedDie's suggestion that "The only way to violate the prohibition against practicing law without a license is to mislead your audience into believing you are a lawyer." That might be true in some jurisdiction somewhere, but it is absolutely wrong in Nevada and in every jurisdiction I am familiar with.
The actual statute in Nevada is NRS 7.285. It does not require any deceit whatsoever. There are several cases from the Nevada Supreme Court discussing what the Unauthorized Practice of Law includes including In Re Lerner, 124 Nev. 1232 (Nev. 2008). One of the interesting footnotes in that case, citing to earlier cases from New York and Ohio states that "the key element of the practice of law is tailoring advice to the needs of a specific client."
Now, as a matter of prosecutorial discretion, my suspicion is that prosecutors and Bar Associations will be much more aggressive about pursuing violations when those violations involve misleading someone and/or accepting payment for the services. But that involves a certain amount of speculation on my part and discretion on part of the enforcing bodies. Nothing in the statute or any case law I am aware of requires any misleading of the client at all or any acceptance of payment.
I do hasten to say that there is a distinction between legal advice and discussing legal information. People are free to discuss the law in every jurisdiction I am familiar with as long as they don't cross the line into giving legal advice. Philosophers might argue that in a democracy the public has a duty to discuss the law. Non-lawyer pundits discuss the law all the time with varying degrees of accuracy. But the more the discussion of the law is tailored to a specific set of personal facts and the more it looks like it contains actual advice about what a specific person can or should do, the more it could at least technically fall within unauthorized practice of law.