The Conjuring Universe was able to achieve this financial milestone in a number of ways. First and foremost, it’s a franchise that contains multiple franchises, similar to the Marvel Cinematic Universe. There’s the main three “The Conjuring” films, the “Annabelle” series (which has three films), and “The Nun” series (which has two films), not to mention the de-canonized but still clearly related spin-off “The Curse of La Llorona.” Contrary to other long-running, lore-heavy movie franchises, each of the installments in the Conjuring Universe works very well as a jumping-on-point. Though the movies do share characters and make reference to prior or future events, each film is its own self-contained story, enough to not alienate first-time viewers.
Moreover, the Conjuring Universe movies contain a variety of creative approaches to the material while remaining tonally consistent with each other. Except for the two directors who’ve made multiple entries in the series (James Wan with two, Michael Chaves with three), the movies all sport different filmmakers, allowing for some variety within the series’ house style. There’s the heartfelt romance and drama of the “Conjuring” films, the haunted house thrills of the “Annabelle” series, and the Gothic, European adventure horror of the “Nun” films. There’s a reason why the first “The Nun” is the highest-grossing movie in the franchise; it’s the most unique entry, but it also builds off the demon nun’s first appearance in “The Conjuring 2,” thus making it appealing to newcomers and fans alike.
Surrounding all this variety is a consistency of tone, at least when it comes to scares. None of the Conjuring Universe films are gore fests, relying instead on the building and releasing of tension within an eerie atmosphere. In other words, these movies aren’t the “endurance test” type of horror, but they aren’t watered-down either, as every entry in the series is rated R, essentially for reasons of cumulative intensity. With each film in the series, there’s an implicit promise to the audience that they’ll have fun and won’t be disturbed, but that they’ll genuinely be scared, too. That’s pretty much the sweet spot for luring general audiences into horror, and the Conjuring Universe has clearly perfected it.