NC-17 movies are films that have been rated by the Motion Picture Association (MPA) as not suitable for viewers under 17 years old. This rating indicates that the content may include explicit sexual scenes, graphic violence, or other adult themes that are not appropriate for younger audiences. Unlike the R rating, which allows viewers under 17 to attend with an adult, NC-17 restricts admission entirely to adults. This rating can limit a film's commercial success, as many theaters and retailers choose not to show or sell NC-17 films due to their controversial nature.