This was originally about the perils of prequels, then I thought about it- surprise!- and realized that many of the struggles writers face in creating prequels also apply to adapting a known work into a different media.
So this is going to bounce around between books, movies, and TV a bit, and I might even treat you to a mild rant, because some of this stuff is elementary, and if I know how to handle Problem X, then a highly paid pro should definitely know how to do it.
The main problem with taking a known IP and doing anything with it is that the audience comes into it with expectations, and they can get really annoyed if you subvert those expectations. Do not meddle with geeks, for they are neither subtle, nor quick to anger, but they are persistent as hell and will protect their fandoms like a cornered cat.
The audience already knows what’s going to happen- or they think they know. They know who’s going to live or die, get married, have a kid, etc. When you’re doing a prequel, all the characters have to survive long enough to get to the main story (or long enough to have descendants who’ll be in the main story, depending on the time scale). If you’re doing a straight-up adaptation and deviate too far from canon, the fans will crucify you. Twenty years later, people are still salty about Peter Jackson’s decision to leave Tom Bombadil out of The Fellowship of the Ring, or the Scouring of the Shire from Return of the King.
Adapting to a visual medium has an additional related pitfall; the fans already have an image of the characters and setting in their head, and the inevitable deviation from that winds people up. Witness the recent kerfuffles over swapping out red-headed white actors for black ones- I’m thinking of the live-action remake of The Little Mermaid, though I’m sure there are others- and when the producers of House of the Dragon decided to make the Valyrians black (at least they’re being visually consistent; Rings of Power isn’t, and it’s rather jarring).
Sometimes image-altering is necessary for storytelling in a visual format, because the characters have to be visually differentiable. Doing it just for the laughs- or worse, for political or activist reasons- won’t win you many friends among the audience.
And now that we’re in the internet age, readers and viewers don’t even have to have read or watched the source material to spoil the ending. That’s how House of the Dragon lost me. I went looking for spoilers and realized that most of the characters were psychopathic murderers who came to sticky ends, usually at the hands of other psychopathic murderers. The guy who ends up winning is still a baby; all the adults have to die first. The one truly good character just died, and it was the first time I came away from interacting with the show not thinking I wanted to wash my hands. But it’s hard to get invested in the struggles of people you know are going to die horribly in just a few episodes.
It’s almost as hard to get invested when you know the character’s going to succeed. Feel-good stories can get away with it, and in most romances, the ending is obvious (of course the two main characters are going to get together). But there’s a distinct lack of urgency and tension when you know what’s going to happen, and that doesn’t work for every genre.
Rings of Power has one way of getting out of the ‘can’t kill that one’ dilemma; Elves can be reincarnated. It’s rare for them to return to Middle-Earth afterward, but the precedent exists. Frankly, that’s what they should have done with Galadriel after she was caught in an explosion in a recent episode. Death and reincarnation might have knocked her arrogant butt off her pedestal, and sent her down a path that logically leads to her becoming the wise leader she is in later stories. It would also help set her up with the correct love interest. Apparently, the writers have something else in mind, because that’s not what happened. But reincarnation or some other form of ‘they’re not really dead’ is a way to have your cake and eat it, too.
On the other hand, you have to get rid of characters who are supposed to be dead. House of the Dragon carefully didn’t kill Laenor, even though he died in the source material. This might cause problems. Since he owns a dragon, he can’t exactly hide anonymously; the idea that he could is kind of world-breaking. And since a dead person’s dragon usually gets passed to someone else, and this guy is still very much alive, there’s going to be a character who’s supposed to have that dragon, and doesn’t. I have no idea how the writers are going to handle that.
Your audience is far more likely to forgive deviations from canon if there’s a good, storytelling-related reason for it. Eliminating Tom Bombadil helped to keep the pacing brisk in Fellowship of the Ring; there was a distinct possibility that including that section would make the story drag. Altering a character’s appearance makes it easier to follow the story without confusing Person A for B, and is good for indicating parentage when you’re following a family through the story.
But if modern entertainment is any indication, adaptations and prequels are hard to get right, and easy to get wrong. Of course, no matter what you do, you’re going to annoy some people, but the makers of popular entertainment seem to be shooting themselves in the foot at every turn.
So why do it? Why adapt a known IP at all?
Money, dear boy.
It used to be about love for the source material, and getting the opportunity to see the same story and characters in a different light. Nowadays, there’s still some of that, but it’s more about tapping into audience nostalgia, courting controversy, and of course, making money.
I’m not going to stomp on anyone for making a buck; money is a large part of how we show our approval of a thing; we’re saying, ‘I value Entertainment Item X enough to trade a few hours of my life for it, both in time spent watching or reading it, and in the money I earned from working.’ Entirely reasonable.
But I think there’s room for new stories, too, and the pitfalls of making them are more manageable.
So I’m going to put my butt in the chair, fingers on the keyboard, and write a few new stories.
Mad Genius Club 
The only thing I know about adapting is that I can’t do it…even if I start with some plot or characters that come from somewhere else, they just drift so dramatically that they become their own thing very quickly.
There is a dude called Dominic Noble who does “Lost in Adaption” you tube series. It is about movies made from books. He does occasionally point out the difference in the medias. The show covers what they left in, what they changed, and what they left out.
Good person to watch if he covers your favorite book.
One wonders from time to time whether they are aware that in fact, there were nineteenth century collections of African fairy tales. You do not, in fact, have to do a palette swap to put a black mermaid in your story.
That would require taking a risk on a new story that hasn’t already sold a bajillion copies.
Much easier to justify spending all that money on something that’s already sold tons and already has 80% of a functional script and plot.
That’s the creative life.
I notice that while the book is better than the movie, the novelization seldom is. A story meant for the screen can be written for its strengths, which are not those of prose.
There are a few instances where I like the movie more than the book, very few though.
The one that comes to mind for me is Wizard of Oz. I like the movie better. Baum’s writing sets my teeth on edge.
The only novelization I thought was better than the movie was *The Abyss.* But the author was allowed to add a lot of backstory for the main characters, which helped the tale.
Dragonheart novelization had some interesting backstory on the characters as well.
It used to be somewhat common in the 1980’s for novelizations to be “better” and/or to include missing scenes. This was a reason to buy novelizations, as well as being a cheap VCR for those of us without them.
But apparently the studios decided that they did not like this, and adaptations are now usually worse, even if done by someone well-known.
It helped that about half of the novelizations were written by Alan Dean Foster, or so it seemed at the time.
Expanding on the story helps, but often doesn’t raise the story enough to make up for the story not being designed for the medium.
Visual is a very different media than print. A bunch of my ideas have been choreographies. Turning those into a written medium instead has been pretty drastic.
Movies can show the huge external grandeur of something, but they cannot show the internal symbology going on in the character’s head. But take the same scene, especially a fast moving and dramatic one, and try to describe the visual effect in print does not work. It simply blogs down.
Instead you have to ride along the symbols the character is using, which means you have to understand what the character is actually seeing. And if you don’t already know how the character thinks and sees, it’s just a real mess.
I suspect that’s why many novelizations of movies fall short.
We’re nearing the home stretch in the Agatha Christie project, where we watch about 200 adaptations (tv and cinema). We’re about to head into the foreign adaptations that have English subtitles.
I write the reviews, we podcast about an episode, and eventually, the reviews will be published as a book.
From having seen multiple adaptations of many of Agatha’s stories, films are so different from words that they can’t be judged the same way.
ITV’s Marple is a prime example. They ran out of novels quickly (only 12!) and for whatever reason ignored the short stories. Instead, they shoehorned Miss Marple into properties where she never existed.
The results are … all over the map. Some (‘The Pale Horse’!) were terrific in their own lights despite not adhering to the text. Others (‘Endless Night’ or the ‘Sittaford Mystery’) were dreadful.
I’ve seen all three versions of ‘The Pale Horse’. They’re all different from each other, none of them show fidelity to the text, and they’re all good to excellent on their own terms.
Film is its own thing. Did it work as a film? Your mileage may vary as a viewer. I’ve had other viewers tell me they loved an adaptation I thought was dreadful.
Which leads me to Angela Lansbury.
She was Miss Marple before she was Jessica Fletcher. Her version of ‘The Mirror Crack’d’ (1980) was not the best film of the three, yet because of Elizabeth Taylor’s star power, it was the only one that showed WHY someone would break quarantine to see a movie star.
One of the worst I’ve seen was the movie adaptation of “Dune”. And its main weakness IMHO was that the screenwriter(s) tried to follow the novel *exactly*, or as closely as possible. “Dune” did *not* convert to visual very well at all.