slowdive.fan wrote...
Keep in mind that this has already been done for previous d&d game engines (dungeon craft - gold box, GemRB - Infinity Engine) and neither of them have received a cease and desist (as far as I can tell). It is very hard to copyright a rules system (just the documents, art assets, etc.).
Are you saying that those earlier D&D games have had their source code released, including the D$D rules embedded in them, or did I misunderstand?