It, the movie that gave us all a reason to be fearful of clowns, became the highest grossing R-rated horror film with $300 million domestic this weekend. The movie, which has been climbing the charts ever since its release on September 8, is a reboot of Stephen King's 1986 novel of the same name. The movie's protagonist is a blood-thirsty clown by the name of Pennywise, who feeds on the children of Derry, Maine every 27 years. 

The horror flick reached the threshold on its fifth weekend in theaters, grossing a whopping $9.4 million, putting it above the $300 million mark. The reason R-rated horror movies have such a difficult time climbing the mainstream charts is because not only do they cater to a very niche audience, but they also have rules in place that call for restricted access (17+ in most states). 

For this reason, PG-13 blockbuster hits usually beat out horror movies at the box office. In box office history, only three R-rated movies have been able to break that $300 million threshold: The Passion of the Christ, Deadpool, and American Sniper

However, It was also incredibly successful in part because it catered to the average millennials connection to the original miniseries. By repackaging It with the special effects and cinematic horror of modern cinema, the film successfully revamped a cult classic.