X Rating is a term used to describe a movie rating system that was introduced in the United States in 1968. It was created by the Motion Picture Association of America (MPAA) and was intended to provide parents with information about the content of films so they could make informed decisions about what their children should watch. The X Rating was the most restrictive rating given to films, indicating that no one under the age of 17 should be allowed to view the film without parental guidance. The rating was eventually replaced by the NC-17 rating in 1990.