Horror films are movies that strive to elicit responses of fear, horror and terror from viewers. Their plots frequently involve themes of the supernatural. Horror movies also usually include a central villain. Early horror movies were largely based on classic literature of the gothic/ horror genre, such as Dracula, Frankenstein, The Wolf Man, Phantom of the Opera and Dr. Jekyll and Mr. Hyde. Later horror films, in contrast, often drew inspiration from the insecurities of life after World War II, giving rise to the three distinct, but related, sub-genres: the horror-of-personality Psycho film, the horror-of-armageddon Invasion of the Bodysnatchers film, and the horror-of-the-demonic Hellraiser film. The last sub-genre may be seen as a modernized transition from the earliest horror films, expanding on their emphasis on supernatural agents that bring horror to the world.
Horror films have been criticized for their graphic violence and dismissed as low budget B-movies and exploitation films. Nonetheless, all the major studios and many respected directors, including Alfred Hitchcock, Roman Polanski, Stanley Kubrick, Francis Ford Coppola, and George Romero have made forays into the genre. Serious critics have analyzed horror films through the prisms of genre theory and the auteur theory. Some horror films incorporate elements of other genres such as science fiction, fantasy, mockumentary, black comedy, and thrillers.