I’m a little bit late to the game, but I just finished reading Dungeon Crawler Carl by Matt Dinniman, and I loved it!
A couple of disclaimers before getting into commentary:
This is a very self-aware, highly meta parody of a D&D style adventure while still being a D&D style adventure.
This series falls into the LitRPG/GameLit genres, which includes a game-style format and character leveling mechanics, but it is NOT a computer simulation.
This story includes gore, language, and crude humor. (Many of the negative reviews of this and future books are about it being too bloody or vulgar—which the author laughingly screenshots and reposts.)
I have been a tabletop roleplayer for about half my life, mostly as a GM/DM (which probably doesn’t come as a shock). And yet, I usually struggle to get into game lit novels because I often don’t believe the characters’ motivations or internal consistency—and I’d often rather run a game myself than read about someone else playing one. Dungeon Crawler Carl absolutely hit all the buttons I needed to stay intrigued and entertained. A big part of why it works so well for me is [minor spoiler] the gamified apocalypse is triggered by super advanced aliens repossessing planet Earth, Hitchhiker’s Guide to the Galaxy style. That took care of a lot, and the main character’s inner monologue and (again) internal consistency handled the rest.
So if you’re the right audience for R-rated D&D-inspired content, I highly recommend Dungeon Crawler Carl.