From Novel to Screenplay: Harry Potter, Arrival and the Impossible Adaptation

By Tom Akehurst

Movie viewers can often be left unsatisfied when they leave the theatre. Such dissatisfaction stems from various causes: an underwhelming performance by their favourite actor or actress, weird or too cartoonish looking special effects, corny lines in the script or an unnecessarily complex plot. But when it explicitly comes to movies based on books, I believe the following statement to be the most common criticism: “The movie was nothing like the book.” This is supposed to be an inherently negative statement about the quality of a screenplay, which through this phrasing is thoughtlessly deemed inferior to the source material it was adapted from. To many people who have read books and then watched the corresponding movie, the latter can never live up to the original. This means: if a movie based on a book is not exactly like it, it is not a good adaptation and, therefore, not a good movie. For these people, it should be the ultimate goal of any movie adaption to be just like the original or as close to it as possible.

My view, however, contrary to what these people argue for, is that movies can and should not be like their source material. There are good reasons for changes, cuts and additions made to a book’s story when adapting it to the big screen. Taking a look at three exemplary book-to-movie adaptations reveals why being “nothing like the book” is an unfair criticism of great movies and their screenplays. 

Size Does Matter

Let us start with a simple reason why screenplays are different to their book counterparts: they have to be shorter. A standard cinematic movie is usually about two hours long, give or take thirty minutes. Books can be of varying length, and therefore demand different amounts of time from the reader to finish them. But with a book you can stop reading at any moment and resume later when you are in the mood. A movie does not have that option (unless of course you buy a disc copy to watch at home, but since most movies are released in cinemas first where you can not press the pause button, we can safely ignore this argument). Therefore, a movie must be of a reasonable length so the audience can watch everything in one sitting at the cinema. This is especially important when it comes to trying to turn a long book into a comparatively short screenplay: there is simply too much source material to adapt, so some things need to be left out in order to achieve an adequate length for the screenplay. And even then, sometimes, parts of the movie are left on the cutting room floor and never make it to the cinema.

Here is an example: Harry Potter and the Half-Blood Prince is a book with 607 pages. Judging from the length of the audiobook, it takes around 19 hours to read every last page. Would anyone be willing to sit in the cinema for 19 hours, missing parts of the story each time when going to the bathroom or getting a snack? Most people would probably not, and so Steve Kloves reduced the number of pages in his screenplay for the movie adaption of Half-Blood Prince to 162, with the final cut of the movie being 153 minutes long. This is a much better length for a movie targeting mainly children and young adults, and Kloves’ strategy paid off: Harry Potter and the Half-Blood Prince made over 900 million dollars at the box office. I do not think this number would have been that high if every single scene from the books had been adapted. Also think about the amount of time and money necessary for such a project. It would be ridiculous to even try if you don’t have millions, maybe even billions, of dollars and years time for production. From a commercial point of view, adapting a book as a whole would be financial suicide for any studio.

The Times They Are a-Changin’

So if it is okay to leave certain plot elements out in a movie adaptation, why would the scenes that make it into the movie get changed instead of staying true to the book? A good question without a simple answer. It largely depends on the individual movie whether changes are justified. Sometimes, there is no need to do something different. But in some cases, there is a need for changes and additions to a screenplay when it is based on a book.

One of these cases is Arrival, a movie by Denis Villeneuve about language and determinism, in which aliens land on earth and a team of linguists is tasked with finding out what they want. The screenplay was adapted by Eric Heisserer from the science fiction novella Story of Your Lifeby Ted Chiang and released in cinemas in 2016. Heisserer changed parts of the story to make it work in the form of a movie, the first one being the titular arrival of the alien species called heptapods. In the short story, the heptapods never actually land on earth as they do in the movie, and instead send down a number of so-called looking glasses acting as “communication devices, presumably with the ships in orbit”[1]. Would you watch a movie in which the protagonists merely look at screens to talk to aliens you never get to see because they are so far away, completely detached from what is happening on earth? Probably not. Such a movie would not be compelling because there is no immediate threat. So Heisserer pitched the following first major change to Ted Chiang: “they show up at our door”[2]. And suddenly, there are things the protagonists (and with them, the audience) wants to find out: How can we communicate with the aliens? What is their purpose on earth? Are they a threat? The tangible existence of the heptapods in the movie as opposed to their only presumed presence in the novella generates public hysteria and military acts of aggression against them, and the actual face-to-face interaction between humans and alien lifeforms inside the spaceship of the heptapods is much more interesting to watch than what Heisserer called having the scientists “spend a year in a room skyping with some aliens”[3]

What I am saying is that in order to sustain a movie of standard length, sometimes you need to add or change something to create a certain amount of tension and conflict so the audience does not get bored and walk out of the cinema saying ‘this was not compelling at all’. To tell an interesting story in the cinema, a screenwriter needs to look at the source material and ask whether it is interesting enough to sustain a movie of two hours. If not, he is free to make changes to it in order to achieve that important goal. After all, if the movie cannot be like the book, it should at least be entertaining.

Movie to Book to Movie

A good example for an entertaining movie with critical and commercial success that was adapted from a book is Your Name. The story follows Taki, a boy from Tokyo, and Mitsuha, a girl from the countryside of Japan, as their lives get intertwined through the sudden event of them switching bodies. Famous Japanese director Makoto Shinkai came up with this story and published it in 2016 – both as a movie and a novel. He finished writing the novel three months before the movie was finished, and has admitted in the afterword of the book that even to him it is unclear which one is the original. He goes on to say that both the movie and the novel can be experienced on their own just fine, but they inevitably complete each other through their media-specific characteristics. This completion happens through changes in perspective.

In the case of Your Name, the novel is written in first person from the perspective of Taki and Mitsuha. What they do not see or do not know cannot be told, and thus, our knowledge of the world, its inhabitants and the events happening is limited to what the two protagonists know about them. The movie though is told in third person, as all movies are in principle, and the audience can see and know everything the camera sees. This broadens our knowledge of things besides the main characters, but also excludes us from knowing their innermost thoughts and emotions. So in order to grasp the whole range of information about the story and everything else in it, interested parties must both watch the movie and read the novel. And yet, both forms can stand on their own, as they tell the same story only from different perspectives. So sometimes, a movie does not cut things out, but adds them in, and the story only benefits from it – even if it is not completely like the book. Ultimately, a book and a movie should be seen as two separate works of art based on the same idea instead of one being the groundwork for the other. 

In my view, stories told either as movies or books, are just like people: different, and all the better for it. We should not complain about one version being different from the other, but rather enjoy both individually. We should not judge movies based on their closeness to their source material, but rather view them as a separate form of expression. And we should not limit ourselves to only one medium, but rather be open for all of them. I think we, as an audience, would be a lot better off.

[1]     Chiang, Ted: Stories Of Your Life and Others. Picador 2015, p. 116

[2]     Quoted from the Audio Podcast “The Q&A with Jeff Goldsmith” Ep. 99 “Arrival Q&A”, available here: (17.01.2018)

[3]     ib.