Filming a novel into a movie usually required a certain fee for the author of the novel. This fee was usually called the "adaptation copyright fee." The copyright fee for the adaptation would vary according to the copyright status of the novel and the production of the movie. If the novel was already protected by copyright, the film production company would have to pay the author the adaptation copyright fee to obtain the use of the adaptation rights. This fee was usually assessed based on factors such as the novel's word count, influence, market value, and so on. If the novel was not yet protected by copyright, the film production company could first adapt the novel into a movie script and then pay the copyright fee to the author. This fee was usually assessed based on the commercial value of the screenplay and the copyright fee. It should be noted that the adaptation copyright fee was not a one-time payment but could be paid in stages. Film production companies may pay adaptation royalties to the author at different stages of the film production process to ensure that the author's participation and contribution to the film production were recognized and rewarded.