Any teenager can buy a movie ticket for “This Means War,” a comedy featuring gunplay, fisticuffs, car crashes and “romantic stalking.”

Or he can go see “Ghostrider — Spirit of Vengeance” a sci-fi fantasy with horrific images, occasional rough language and, according to the New York Times, “painful-looking urination.”

In either case, the newspaper of record’s movie adviser says “parents are strongly cautioned.”

This is no surprise: Moviemakers leave nothing to chance and push their films to the PG-13 limit — but not beyond — so they can maximize size of their audiences. Nonstop violence and sexual innuendo don’t trip a film into an R rating, but certain words do.

These are words that don’t get published in this newspaper, but they are commonly heard in many places in our society. One of them appears six times in the new documentary “Bully,” earning the film an R rating, meaning no one under 17 can buy a ticket.

Unlike the PG-13 films mentioned above, this one is not mindless entertainment. It tells the real-life story of students who are bullied in school and the price they pay as a result.

We all know the stakes: Bullying has been linked to several high-profile suicides and the recent deadly school shooting in Ohio.

Countless other students have lost the chance to relax and pursue an education as a result of bullying, and it is a vital subject for conversation in middle and high schools. A provocative film could get that conversation started, but it won’t happen with this film unless the teenagers are willing to go to the movies with their parents.

The Motion Picture Association of America ratings are voluntary and are supposed to provide families with some guidance of which movies are appropriate for viewing by audiences of different ages. But mindless adherence to rigid standards will just mean that some young people will not be able to see this film.

An R rating should be reserved for films that deliver a message inappropriate for teens, not ones that tell them exactly what they should be hearing.