To be honest this more me blowing off steam than actually asking a question but I need to get this out of my system. So Sunday night I ran a game, everything was going great until one player tried to use hold person on an incubus. Now for most this a simple thing they are fiends not humanoids therfore hold person does not work on them. However the entire group got into an argument about Whether or not incubi are humanoid because they look humanoid even though the monster sheet clearly states that they are fiends not humanoids. This argument went on for an hour with the biggest argument coming from one player who was making the "rules as intended rather than rules as written" argument. His example involved getting a bunch of people together and having them pass a stone in a strait line. According to him because of turn economy the stone would continue to speed up indefinitely until it reached the end. Which is technically possible because of how the rules are written but that's not how they were intended so the some concept applies here. Eventually I decided to make it so that hold person works on incubi and sucubi as an exception. But like wtf is with this I don't get how such a simple thing can be argued. They also tried to make the same argument for giants but as we all know they are not humanoids they went as far as to use the art from the monster manual to back their point. Just to ask a question has anyone else experienced this? How should I have handled this? Am I justified in dispute loving my party with all my heart to be a little pissed off?