Sometimes we wish we knew. The Motion Picture Association, otherwise known as the MPA, assigns movie ratings. For more information about the ratings system as well as the reasons specific films receive the ratings they do, visit filmratings.com. Another useful site designed for parents is screenit.com. Companies that are not required to have their films rated because they are not members of the MPA release some of the films we play. The ratings system is entirely voluntary for non-MPA member companies and it is up to each company to determine whether having a particular film rated is worth the expense of doing so.