The difference between a horror story and an action story is in how much the hero knows
I think this is smart and a great rule of thumb vis-a-vis horror narratives.
Mightygodking dot com -- Fear of the unknown vs. fear of the known vs. forewarned and forearmed
In other words, the difference between a horror movie and an action movie is, mostly, the protagonist’s degree of knowledge. Which means as any horror narrative continues and develops, it by necessity has to gradually drift towards being an action movie (or something else, but action is the easiest progression because the two genres are so similar and both strive to hit the same adrenalin-producing nerve in the viewer), simply because the protagonist will learn more and more – you can see this even in many regular horror movies within the three-act structure where the hero, in the third act, finally confronts the baddie. That progression is practically a staple of slasher flicks, and so slasher flick franchises generally invert the formula and remain horror films by having new protagonists in each installment while keeping the same baddie around. Of course, then you run into the problem with that formula, which is that each iteration will feel more and more repetitive until you decide to put Jason in space because what the hell else is left to do?
