This year, I've decided to participate in cinemonster's ongoing Hooptober X challenge! letterboxd.com/cinemonster/list/hooptober-x-hooptober-hooptober-let-satan/
However, there's no way in hell (pun intended) I'd watch 31 films in 31 days with a friend's wedding coming up and hopefully moving soon. So I'm modifying it to retroactively include some films I watched in September, given that's when I start intentionally watching horror every year anyway. I'll also be double counting films to meet multiple criteria, i.e. The Descent being 10 years after I was born and about something underground. But if I finish with time to spare then I'll add some more!