 The script about 550 pages long when completed, about four times the size of an average Hollywood screenplay. The script included another 100 pages of storyboards, representing a total of 800 scenes. In preparation for writing it, Williams spent six months watching horror films and reading horror novels, as well as books about how to write horror novels and screenplays. She also asked people she knew socially to tell her scary stories so she could identify the elements of fear. Williams immersed herself so deeply into the genre that she began having nightmares and had to scale back her reading. Williams also spent about six months researching historical aspects of the story before the writing process. Williams had a history of using female protagonists in her games, like the Laura Bow series and some of the King's Quest games. She said having a female lead in Phantasmagoria was not a ploy to attract female gamers, but rather felt like the correct choice for the game. Williams said her own personality was a partial inspiration for the protagonist Adrienne, although it was not purposeful: "I think it just kind of naturally worked out that way."
