Day 19 - Scary.
Interestingly enough, while I have run some horror rpgs in the past - notably Chill, Call of Cthulhu and Unhallowed Metropolis to name the more memorable ones - I'm not a fan of the horror genre, and don't tend to read scary stories, watch scary movies, and so forth.
That said, when I'm looking for inspiration to scare my players in a game, and it should be noted that doesn't mean it's a horror genre, I tend to think back to what scared me as a child and into my teen years. Being scared is mostly about the fear of the unknown, but our formative years shape us in so many ways and lend the creative writer (or game adventure writer) lots of different forms and shapes that our fears, and hence what makes us afraid or scared, take.
Naturally, the key when doing this sort of thing with your players is knowing when *not* to do so.
And there you have this nineteenth post for #RPGaDay for August, 2019. Comments, thoughts, questions, etc. are all welcome, of course.