/x/

/x/ is a 4chan board dedicated to the paranormal. It was created in January 2005 as a general photography board and repurposed in February 2007 as a paranormal board. The board is known for originating the SCP Foundation, the creepypasta genre, and the Backrooms phenomenon. The SCP Foundation began on /x/ in 2007 when an anonymous user posted the first SCP file, SCP-173.

More files soon followed, copying its style and building a shared universe; the project moved to its own wiki in January 2008. Many early creepypastas were created on /x/, including Ben Drowned, posted in September 2010 by an author pretending to be a user with a glitching video game. The Backrooms started from a thread on May 12, 2019, where users were asked to share unsettling images. The first Backrooms photo was uploaded there with a story about "noclipping out of reality," and the concept later spread widely on social media.

The board also helped investigate and popularize the controversial game Sad Satan. American model Allison Harvard first gained internet fame on /x/ in 2005 as "Creepy Chan" due to her appearance and interests; she later appeared on America's Next Top Model in 2009 and 2011, visiting /x/ to discuss herself.