Developed by Swiss psychiatrist and psychoanalyst Hermann Rorschach in 1921, the Rorschach Test is, basically, a set of cards containing pictures of inkblots that have been folded over on themselves to create a mirror image. It's what's referred to as a projective test; meaning, when a person is shown an ambiguous image, their mind will work extra-hard to give it meaning.
When someone tells you what they see in the inkblot, Rorschach theorized, they're really telling you about themselves. At one point it was a tool for diagnosing schizophrenia—Rorschach observed that patients with this disorder often saw radically different images in the splotches—but it's since been widely dismissed by the psychiatric community.
The pictures are still fun to look at, though! Check out a few images from the original test, below, and scroll down to see what most people report seeing in them.
Inkblot A: Bat, Butterfly, Moth
Inkblot B: Two Humans, Dog, Elephant
Inkblot C: Skin Rug, Animal Hide, Skin
Inkblot D: Crab, Rabbit Head, Caterpillars