You can. But there is no reason to suppose they did. It's not normal in publishing (J. K. Rowling still owns the rights to Harry Potter).
RPG publishers typically license the rights to publish an RPG based on an IP for a period of time. They don't buy the rights. FFG hasn't bought Star Wars. Cubicle 7 didn't buy Middle Earth. Modiphius isn't the new owner of Star Trek. I don't own Judge Dredd. You license them, usually in exchange for an advance on royalties and ongoing royalties.
Critical Role will have licensed the rights to Green Ronin to publish a book in exchange for royalties. Green Ronin may or may not have just lost the rights they licensed from Critical Role. It's a rental arrangement, not a purchase.
Last edited: