I liked The Warlock In Spite of Himself when I was a kid. Rereading it, I see a few more flaws than I did. The one that bothers me the most is the colloquial, already-dated topical references in a story that’s supposed to be three thousand years after the present day.
Here are some of the jokes that people will still get in 3000 years:
“This was as dark as Carlsbad before the tourists came.”
“Well, I wouldn’t exactly qualify for first chair in the Philharmonic, but…”
“Matter of fact, she was stacked like a Las Vegas poker deck.”
There are good moments, though: for instance, all of the nobles come with their own creepy alien Wormtongue advisors:
Next to each of the great lords sat a slight, wiry, wizened little man, an old man; each had an almost emaciated face, with burning blue eyes, and a few wisps of hair brushed flat over a leathery skull. Councillors? Rod wondered. Strange that they all looked so much alike.
In a D&D campaign, I think I’d have it become apparent that none of the nobles knew that the advisors were there.