Not sure you can copyright claim a fantasy race, with tieflings for example having a very broad description, but if i was to use a character of theirs like Vecna or a place like waterdeep maybe.
Either way im sure the sword coast will never notice my little porn game, maybe when im on steam but thats a problem for later.
My understanding (feel free to fact check me) Dungons & Dragons created halflings because they could not use the term hobbit. Goblins, trolls, and dragons were in the public domain, but hobbits was an orginally creation of J. R. R. Tolkien. Someone on behalf of J. R. R. Tolkien estate did file a file a lawsuit when Dungons & Dragons orginally included hobbits as a playable race, and Ents as monster that players could encounter.
Both sides agreed to settle the case out of court. Dungons & Dragons agreed to make changes turning their hobbits into halflings, and their Ents became Treants to avoid copyright infridgment.
Their is an animate I watched called Delicious In Dungeon, they have a species that clearly is inspired by halflings, but they are not halflings, in Delicious In Dungeon they are called Half-foot. I am assuming to avoid copyright infridment.
So if Dungons & Dragons does have a copyright to the things I mentioned, you might be able create something demon like, that is inspired by tieflings, but you cannot call them tieflings. Maybe more one or two other small changes, I don't know what the full lore on tieflings are. Or having people that have cat traits is in general concept that could be used by the public, but you might have to call them something other then tabaix.
that's fine i don't mind either way im gonna be 100% with most of my players don't really care about D&D or know the races, the D&D stuff is just a little extra for those who get it. i don't mind changing the name of some races if i have to. but as of right now im not selling the game, so it's basically just fanfiction which they cant do shit about .
Somethings a name change migth be all that is need. When D&D turned Hobbits to Halflings, on top of changing the name they also got rid of the Hobbits hairy feet and made them all wear footware. And the Delicious In Dungeon example I gave, they made their Half-foots all have big round ears. If there were other changes made, I am unaware of them.
Free tip when making up your own word for something. Type your made up word into a search engine or two, just to make sure you did not miraculously spell a real word in another language. This happened to me once. I typed my made up word I going to use for the name of alien species, discovered that if I swapped places of two letters I would have spelled foreign language's word for insest. Not a term I wanted this entire species to associated with.
In case anyone was wondering, no I don't remember the language. It was way too long ago.
