A horseshoe nailed above a doorway is a good luck charm if it looks like a U.
A black cat can be considered good luck or bad luck.
A superstition is a belief that has no logical explanation or scientific evidence. There are many superstitions believed in around the world. Many people believe superstitions to be complete nonsense while others live their lives according to superstitions such as avoiding black cats, looking for four leaf clovers and avoiding mirrors.
Common Superstitions- Black Cats can be good or bad luck!