But that is where lines and veils come in.
But for the big things, like rape? That's something that doesn't have to be put into an official book because it doesn't actually add anything to the game as a whole.
I would draw a line here.
How do we approach rape in tv, movies, and books? The answer should be either that we DON'T,
or we approach it with maturity, respect and caution. What is maturity, respect and caution? It starts with: Don't throw it in - but if it has a purpose, consider if it is an acceptable use.
TV, movies and books are storytelling. So is D&D. To me, there is still an appropriate place for the inclusion of highly offensive concepts in a role playing game, but they have to be handled with maturity, respect and caution.
Many people would draw a line that says it absolutely should never ever be included in a game. That is fine. That belief, however, also isn't going to be universally accepted. To that end, we need to consider what is the best way to address the situations where that approach is not followed. And how might we achieve maturity, respect and caution when it is to be used? With appropriate training.
Where do we get our training on how to play the game? Primarily: the books.
Does this mean every game should allow discussion of rape? Absolutely not. DMs should use session 0s and their own evaluation of a situation to decide what is appropriate for their game table. I expect many, if not most, would say it should be excluded.
Does this mean I think we should have a chapter in the main DMG about how to approach rape in your campaign? NO. It does not. Howeverm, there should be a chapter in the main DMG that trains us on how to use a Session 0 to determine what is appropriate for the group and game being run.
And I believe we should have guidance in
some book to help DMs learn to approach the topic with maturity, respect and caution.
A game with the inclusion of offensive concepts is not for everyone. These offensive concepts do feed into some types of fantasy stories that some people wish to include in their games, including games that tackle historical wrongs, games that are trying to evoke a harsh world like Game of Thrones, and others. Those games are not for everyone. But, when those games are going to be run, I'd rather we provide DMs (and players) with tools to approach them with the maturity, respect and caution that a good author uses when approaching them in their works.