Since Mark Twain did A Connecticut Yankee in King Arthur's Court, there's always been a desire by some people to be the guy who goes to a fantasy world in order to make use of their knowledge to take over. Err, I mean be a big hero. My favorite of this subgenre is probably Army of Darkness followed by Eric Flint's Ring of Fire series. Still, Blaise Corvin's Delvers LLC has probably supplanted the latter as my second favorite of all time. The only reason it's not at the top is because, well, Bruce Campbell.
The premise is Jason and Henry are a pair of martial arts enthusiasts who get kidnapped by the Great God Dolos (bolded for emphasis). Dolos is effectively a being akin to Q from Star Trek: The Next Generation only obsessed with Dungeons and Dragons or World of Warcraft (depending on what decade you grew up in). He's omnipotent or close to it and has populated a planet with elves, humans, goblins, beast people, and orks.
Even more so, he's created a bunch of dungeons spread across the planet full of treasure as well as magical items designed to simulate leveling up. Dolos outfits the pair with a couple of orbs and tells them to go onward, Christian soldier, and kill some monsters for loot. The rest of the book follows them in their confused attempt to deal with the fact they're now trapped on a Gygaxian death world.
As the writer of the Supervillainy Saga series, I'm aware of a rule which Blaise Corvin seems to be, which is that any premise can be sold to the reader as long as its implication are well thought out as well as presented sincerely. The idea of a god playing a fantasy tabletop game with real people is absolutely insane but it works because the characters take it seriously. They discuss things ranging from: "is it right to kill people", "are the monsters we're killing actual people", "how do we survive in a world based on violence", and "can we get home?"
If I have any real complaint about the book, it's that Jason and Henry are a little too well-adjusted to the insanity around them. I'd have thrown in a bit more, "Is that a frigging elf? That is a frigging elf!" Then again, Jason has the ambition of nailing a cat girl before he discovers they're not the anime kind so I can't complain too much. Jason and Henry may be both straight men but they each have specialties with the former being a trained soldier while the latter having a science-fiction/fantasy background.
Really, I'm pleased to say the supporting cast from Ludus is even more interesting than the protagonists. Mareen and Uluula are more than mere love interests for the character with the former being a fairly well developed fantasy archetype (farm girl turned adventuress) while the latter is a Space Elf stuck on a planet full of primitive screwheads. I'm also pleased Corvin tackled the issues of romance, courtship, and sexual taboos are different on Ludus than Earth. It may sound a bit peculiar but I'm actually interested in seeing if Corvin will tackle polyamory in the setting. The rest of their adventuring company is also entertaining with their own arcs and story beats.
Dolos, himself, is a great character and a fine fantasy villain that comes close to being Handsome Jack levels of hateable. For example, one thing I loved is how he misleads the various races into killing one another while making it seem it's all in good vs. evil fun. That's some dark and disgusting stuff from a man who is just doing this as a giant experiment. The cover of my copy really captures what a smug jackass he is, complete with little crown.
A fair warning for more sensitive souls, part of how the book sells its premise is the fact violence is unsanitized. People die horribly in the setting and Ludus is kind of a hellhole where the strong prey on the weak. There's allusions to rape and sexual slavery as well as one scene where a female character has to fight off a sexual predator. The dissonance with the colorful premise gives the book a distinct flavor, though.
In conclusion, I recommend Delvers LLC quite strongly. It's entertaining and has an original premise with characters I actually care about. The women are arguably more interesting than the men but I wanted them to hook up with their love interests--which is rarely something I care about in books. I also like the set up for a full-length series as a lot of seeds are planted for the eventual fall of Dolos (or not).