PG-13 rated movies stand for Parental Guidance-13, with parents strongly cautioned, as some material may not be suitable for children under 13. Again, it’s a matter of what isn’t in the film; any nudity has to be non-sexual, any swear words have to be used sparingly, and, in the event of the specific obscenity we politely call the F-word, not used in a sexual context.
(You can say “Oh, (BLANK) this!” in a PG-13 film, but not more than once, and never “I’d love to (BLANK) Denise …”) Violence in PG-13 films may be intense, but must also be bloodless – see Jurassic World or any Marvel Movie, for example – and it is, as per usual, the Ratings Board’s call if the film's content is deemed to be more than PG but less than R.
Rated R movies mean Restricted, with no one under 17 admitted without an accompanying parent or guardian. This rating is given for strong and frequent language and violence, nudity for sexual purposes and drug abuse.
Movies with an NC-17 rating mean No one under 18 admitted. This rare rating is given to films which feature mature elements in such profusion – or in such intensity – that it surpasses even the R. The MPAA bases this rating on the assumption that most parents would not want children to see this material without supervision – and, of course, it’s their definition of “Most parents.”
PG-13的电影例如 The Dark Knight, The Dark Knight Rises, Star Wars: The Force Awakens
R rating的电影例如 Deadpool, Matrix, the Usual Suspects, Gone Girl, the Godfatherhttp://www.boxofficemojo.com/alltime/domestic/mpaa.htm?page=R&p=.htm