Stories that originated on r/NoSleep and breached containment
The subreddit r/NoSleep is a forum for horror stories. The way that this sub differs from other writing forums is that stories must be framed as "personal" scary stories that "really happened" to the poster--they are all fiction, but on the sub, "everything is true even if it isn't." 99% of stories are in first person POV, and the submitter has to have "realistically" survived the story in order to post about it on the internet.
Over the years, some stories grew in popularity and were published as novels or adapted into other formats. In this post I will share my favorites so you can be spooked too! These are not in any particular order!
1. How To Survive Camping by Bonnie Quinn
In a small town in an undisclosed location, Kate's family has been managing a campground of old land that has been in their bloodline for many generations. The public is welcome to come in and enjoy the natural beauty of the woods, but you really should follow the guidelines she mails to all campers so that you have a pleasant time and survive your vacation. There are things in the woods that are neither human nor flora nor fauna.
This series originated on r/nosleep and I got to follow it as it was still updating, but Quinn scrubbed it from reddit when she got her book deal. What was previously 30+ posts on reddit is now 4 published books: The Man With No Shadow, The Lady In Chains, The Ancient Things, and The Beast. Having read the stories in real time as Quinn was uploading them, I can confirm that things were edited, moved around, and expanded to be really awesome books that have a small fandom here on Tumblr (that I hope continues to grow! I love Kate so much, she's the grizzled aroace campground manager we need).
https://www.goodreads.com/series/376837-how-to-survive-camping
2. The Left/Right Game by Jack Anderson
There's a creepypasta-esque legend that says that if you get in a car, and drive in a way that you make alternating left turns then right turns for long enough, you'll drive into an alternate reality. This isn't easy to do, because you'd have to follow that pattern for a long, long time, and eventually you just run out of road or gas or the streets don't follow the turns you want to make, but it turns out someone was dedicated enough to try it in as many cities as possible, and he.... succeeded. If you play the Left/Right Game in Phoenix, Arizona, starting in just the right spot, you will eventually leave Phoenix for somewhere different. But god help you if you don't follow the rules of that new dimension.
This story is still available to read on Reddit! All parts are available at this link. This story was adapted into an audio drama podcast, starring Tessa Thompson as the protagonist Alice Sharma. It's available where most podcasts are, including Spotify and Apple Podcasts. The story is TREMENDOUS and its one of the things that changed me to read and hear. I think this was one of the stories that made "rules horror" such a powerful subgenre. And word is that the TV rights have been secured for this! It may eventually make it to TV!
3. Penpal by Dathan Aurebach
One of the most infamous r/nosleep stories, and one of the first to get published, Penpal is........ devastating. I cannot recommend this book to anyone who is a parent to young children. The story is kind of a memoir, with the adult protagonist looking back on some weird stuff that happened to him as a kid, where he didn't understand the gravity of any of it. It's a rare horror story that doesn't contain any gore, rape, sexual violence, gruesome murder, or jumpscares. It nonetheless is a suspenseful horror novel that gives me goosebumps even to think about the ending. I randomly remembered it while walking around on a humid June day and my whole body went cold.
https://www.goodreads.com/en/book/show/14578407-penpal
4. Borrasca by Rebecca Klingel
In a mining town in the Ozarks, people sometimes go missing and there's an occasional loud noise that you're not supposed to talk about or acknowledge. And people have a really, really hard time getting pregnant or having families, and these things may or may not be related. The protagonist Sam and his friends investigate these mysteries.......... and they don't like what they discover.
This story is still available to read on reddit at this link! It blew up when it was first being published on the forum, and the author was discovered by horror filmmaker Mike Flanagan and hired to be one of the writers on his Netflix shows! Borrasca was made into an audio drama podcast by the same studio that produced The Left/Right Game and stars Cole Sprouse as the voice of the protagonist. The story is haunting, and devastating, and will break your heart whether you read it or listen to it.
This is by no means an exhaustive list-- but these are my favorites! Hope you give them a looksee!