A novelization (or novelisation) is a derivative novel that adapts the story of a work created for another medium, such as a film, TV series, stage play, comic book or video game. Film novelizations were particularly popular before the advent of home video, but continue to find commercial success as part of marketing campaigns for major films. They are often written by accomplished writers based on an early draft of the film's script and on a tight deadline. History and purpose Novelizations of films began to be produced in the 1910s and 1920s for silent films such as Les Vampires (1915–16) and London After Midnight (1927). One of the first films with spoken dialogue to be novelized was King Kong (1933). Film novelizations were especially profitable during the 1970s before home video became available, as they were then the only way to re-experience popular movies other than television airing or a rerelease in theaters. The novelizations of Star Wars (1977), Alien (1979) and Star Trek:The Motion Picture (1979) sold millions of copies. The first ever video game to be novelised was Shadowkeep, in 1984. Even after the advent of home video, film novelizations remain popular, with the adaptation of Godzilla (2014) being included on The New York Times Best Seller list for mass-market paperbacks. This has been attributed to these novels' appeal to fans: About 50% of novelizations are sold to people who have watched the film and want to explore its characters further, or to reconnect to the enthusiasm they experienced when watching the film. A film is therefore also a sort of commercial for its novelization; the film's success or failure affects the novelization's sales. Conversely, film novelizations help generate publicity for upcoming films, serving as a link in the film's marketing chain. According to publishing industry estimates, about one or two percent of the audience of a film will buy its novelization. This makes these relatively inexpensively produced works a commercially attractive proposition in the case of blockbuster film franchises. The increasing number of previously established novelists taking on tie-in works has been credited with these works gaining a "patina of respectability" after they had previously been disregarded in literary circles as derivative and mere merchandise. Variants Film The writer of a novelization is supposed to multiply the 20,000–25,000 words of a screenplay into at least 60,000 words. Writers usually achieve that by adding description or introspection.