New Line CinemaHorror is one of cinemas most diverse genres. Both slasher movies and haunted house tales fit under its umbrella, but the two couldn't be more different. It's a genre that branches off in many directions, but it bears so much fruit that some of it has to be rotten. The genre is also unique for its absolutely stunning commitment to sequels. Few genres are so keen on spinning an idea out for as long as humanly possible. The three most famous horror franchises - Halloween, A Nightmare On Elm Street and Friday the 13th - add up to more than 30 movies. Outside of Marvel's Avengers universe, it's tough to find a franchise that even stands a chance of running that long. Unfortunately, with that longevity, there's a lot of pressure on each installment of a franchise to get better, which leads to some truly bizarre risk-taking. The same is true of stand-alone films that are attempting to position themselves into a crowded sub-genre, such as the recent obsession with demonic home invasion tales (Sinister, Dark Skies, Insidious, The Purge). One of the easiest traps for a horror movie - especially a long-running franchise - to fall into is that of excessive silliness. Scary movies often try to bring in aspects of fantasy and comedy to spice up their storytelling and mark them out as original. Sometimes this works like a charm, but occasionally the film can become too silly to scare anyone.