hey and hello y'all'ins. so this probably won't apply to most folks and a lot more just won't care and that's fine, but i thought i'd bring some attention to a recent SCOTUS ruling that has (or at least will) fundamentally changed the way copyright works in the states, which in turn likely means any other countries participating in the WIPO treaty and Berne conventions. to start, i'm not a lawyer and if you're dabblin' in the black legal arts and you can afford it, you should get a lawyer. you can also go to your local legal aid society for free/cheap help but they rarely do IP law stuffs, but its always worth a check.
at any rate, prior to march 4th basically all you had to do to own your IP is make the damn thing. that's still true, however, courtesy of Fourth Estate Public Benefit Corp. v. Wall-Street.com you now must have registered your copyright with the libary of congress before you can commence a lawsuit against some n'er do well. not only must you have registered your copyright, the LOC must have processed the application. this is a game changer, because it contradicts the literature of the copyright act as well as prior SCOTUS rulings. it also means that there will be heavy pressure on the registrar as it takes some 8 to 10 months to process an application already; it'll go up. Jordan Franklin has a pretty good opinion piece you can read here, and she IS a lawyer. her point about is statute of limitations is on point, which i think is extremely relevant to the sort of re-discover-ability that RPGs tend to have.
so that's something to watch out for! again, i am not a lawyer and this is not legal advice, but i keep up with IP law pretty hard because i do art/game stuffs for other people a lot and sometimes you gotta know some legal stuff. if anyone has any questions i can try to answer as best and non-legally binding as i can, or point you to a better resource.