This is called fanfiction, and unless he changes significant details (names, settings, etc.) it would not be publishable without permission. There are places you can post fanfiction - An Archive of Our Own is by far the most popular these days, but I think Fanfiction.net is still chugging along somewhere on the internets. He wouldn't be able to submit it to a traditional publisher or self-publish on Amazon though.
1. Jokes may be eligible for copyright protection. Their length can be a problem. Also, whether Boyle originated the joke or heard it elsewhere, made a variation on an existing joke, etc. are important. It's probably a low-risk use, but not a no-risk use. 2. Characters can be protected by copyright if they're well-defined enough. It's a case-specific question, though I suspect a character developed over the course of a TV series may qualify. A book continuing such a character would probably be a copyright violation, and TV studios are usually fairly aggressive about such things. There could also be trademark issues involved depending on how the book is marketed. The comments above are based on U.S. law. Other jurisdictions can vary.
I have been working, on and off, on a story about a musician. The inspiration behind it is the 1980's film, The Jazz Singer. I believe the film was based on an earlier film of the same title released sometime during the 1940's. The only similarity to the film is that the musician has a 'meltdown' and disappears for a while. Having said that, the working title, storyline, names, places, reasons why etc differ. Will there be an issue with copyright? Edit: Can't believe its been 40 years since I first saw this film
Lauren Kelly and Steerpike many thanks for your replies. I'll pass on the fanfiction stuff to my mate but he has offered, since I posted, that there is no way he'd publish for money/profit. It is largely just for fun and to share with family and friends. The trouble is I know how these things can start off small, fire the imagination, and transform into a life consuming monster As for the joke it is very simple. It offers to visitors two views of a place, both in the present. But one reflects an activity from the distant past, implying that the place is very backward. I'm sure that I could find prior examples of this joke structure. Maybe I'll just change the place, and the two views, and see if it still works. Or maybe it's just the way Frankie tells 'em
Nah, not even close. My first book is set in a cooking competition that, if you squint sideways at it, is basically Top Chef. I'd be lying if I said it wasn't my primary inspiration (although there are elements of Hell's Kitchen and Chopped, as well as several non-fiction chef/restaurant books), but I came up with a lot of my own original details that I think set it apart well enough - the name of the competition, catch-phrases, judges, contestants and even some of the challenges. My publisher at the time wasn't worried at all about possible copyright infringement, even though anyone who's familiar with Top Chef can see the conceptual similarity.
And by virtue of there being multiple shows with the same (or similar) concept with no issues of infringement, you can kind of see how the spirit of copyright works. Unrelated note: a couple of Top Chef winners in Providence have recently lost their restaurants, I think.