Horror filmmakers love leaving things to the imagination. That's because oftentimes what's not explained is a lot scarier than what is explained, so you'll never really know what the Blair Witch looks like, the extent of Jason's immortality, or if The Babadook is real. As a result of keeping so many things unanswered, that leaves room for some great fan theories to fill in the blanks.
While a lot of fan theories can feel like they're reaching, arbitrarily deciding all the characters are in purgatory based on no evidence, there are some that can radically alter your perspective on a film forever. Viewers will piece together the killer's backstory that the director didn't fully explain, or maybe make sense of that totally bonkers ending that was scary but also weird and confusing.
Really, although horror has a reputation for being pretty simple and without much subtext, it's probably the genre where fan theories are most appropriate just because there's so much left to expand on by the time the credits roll. If a few of your favorite scary movies left you scratching your head, or if you just want a new perspective on some classics, look no further than these 10 awesome theories.