Watch out for any black cats, avoid breaking mirrors, and make sure you don't walk under any ladders; it's Friday the 13th. But what makes people so superstitious on this day?
Biblical claims and stories about knights in the middle ages have been debunked, notes CNN, who attributes the hysteria to a book written in 1907 by Thomas W. Lawson titled, Friday The Thirteenth.
Perhaps the movie franchise by the same name didn't help either, as Gallup found in the 90s that 1-in-4 Americans consider themselves superstitious.
But it isn't all bad news. Apparently airline tickets drop in price on Friday the 13th.