This book collects several short stories about the pulp fantasy duo Fafhrd and the Grey Mouser, detailing their histories and how they came to be partners in adventure.
Fafhrd and the Grey Mouser are sort of credited as the grandfathers of the modern day fantasy protagonist as the self-interested antihero, but in this case I think they're the type of grandfathers that make everyone uncomfortable and tell racist jokes.
This review should contain no significant spoilers.
This may be one of the most sexist fantasy books I've ever read, which is saying something. Women are uniformly portrayed as helpless waifs who take advantage of their sexuality in order to harness masculine power for their own ends. This uncomfortable trend weaves its way into the storyline to such an extent that it's impossible for me to write it off as merely a sign of the times.
The characters themselves aren't terribly likable, being selfish jerks who aren't even terribly clever or stylish about it. Fafhrd and the Grey Mouser never seem to have much of a plan, they seem to survive based on coincidence, dumb luck, and being better at fighting than their foes. Secondary characters will often speak for the benefit of the audience, announcing plans or other information to each other when it doesn't really make conversational sense just because the reader wouldn't know it otherwise. At one point in particular, a character began giving their longwinded backstory without any particular prompting. At times this serves the grand, epic style of writing that made me love the original Conan the Barbarian movie, but other times it's just jarring and makes the characters feel inhuman.
Reading this book, I couldn't help but see no small part of every fantasy city in Lankhmar... from King's Landing to Ankhana... from Ankh-Morpork to the unnamed City of the Thief videogame series. It's really clear where the fantasy genre was changed by this series of novella and short stories. However, simply being the first to come up with the idea of making a fantasy city crowded, sooty and run-down doesn't mean you deserve a place in history. Many more interesting stories have taken place in these Lankhmar-alikes than those told in Swords and Deviltry.
I should be fair, this book contains only a tiny fraction of Fafhrd and the Grey Mouser's adventures, and it's possible others justify the reverence Fritz Leiber gets from modern fantasy giants, and the great affection people hold towards his iconic characters. Still, having read this book, it's not because of the stories here. The characters' backstories weren't interesting enough for the writer himself to have started with them, so you might as well skip them too.