Yes, the Russian Roulette joke, and it might not even be him. It's tickling the back of my brain. It might be an old-time author joke that floated around. Or maybe it was Harlan Ellison? I'm just not sure? It might be one of these things that authors secretly think of independently a lot when banging their head on the wall?
Donald Westlake was an old-school mid-late 20th century mystery writer, really hilarious, sometime when you've got some beach read time, you might want to check him out. Your sense of humor might harmonize with him. There was a movie too, I think. "What's the Worst that Could Happen?"
Anyway, I enjoyed your illustrations very much if I forgot to say so before!