I know the rating is 18, but personally I think that is unreasonable and totally depends on the film.
My 13yr old is not allowed to watch psycho/horror gore Halloween type films such as Halloween at this rating, or sexy stuff such as Wolf of Wall Street
But he has gta on his computer due to him moaning to me that his friends have it and he wants to be able to play with them.
He is also currently on to season 2 of breaking bad, which I didn’t realise he was watching until yesterday as he’d binge watched it whilst ill and I was in work. I’ve seen them all and know what to expect. I don’t want to stop him because he’s really in to it and I know if it was me I’d be pissed off.
yabu - bad bad parent
yanbu - it depends on the individual film/game?