An adult rating is a type of rating that, when applied to a film, video game, or other form of media, restricts its viewing audience to persons aged 18 years or over. The X rating from the MPAA was a famous adult rating, due to it being used by the pornography industry and films with that rating being mistaken as such. 18 is a very commonly used age restriction. The BBFC's 18 certificate is also used as an adult rating. Adult ratings may be fully restricted to keep underage children from seeing graphic violence, very explicit language, pornography, or any other strong material that most parents would find unsuitable for their children 17 and under. Children generally are not admitted to an adult-rated motion picture under any circumstance.
