There are hundreds, perhaps thousands, of superstitions the world over, but none are more important than the one you personally subscribe. And if you believe in lagomorphs of fortune, losing a lucky rabbit's foot signals bad luck as surely as carrying it promises to bring good luck.
Thousands of years ago, people in Western Europe were toting around the foot of a hare, the rabbit's larger relative, because they believed the limb was imbued with magical properties. Eventually, both a hare's foot and a rabbit's were considered lucky. After all, it isn't easy to distinguish between the two once they're separated from their original owners.
The belief that a rabbit's foot could be charmed, and therefore help one lead a charmed life, began as an offshoot of totemism. This belief in a spiritual connection between humans and other living beings dates back thousands of years. A tribe that considered itself descended from hares or rabbits worshiped the animals and carried parts of them for luck. The foot was particularly lucky; it was a phallic symbol, a totem that represented not only good fortune, but also increased fertility and a bountiful harvest. Celtic tribes believed rabbits spent so much time underground they could communicate with gods and spirits, so, naturally, carrying a rabbit's foot would be lucky [source: Panati].
The luck of the rabbit's foot endured generations and crossed into modern culture. By the 16th century, the rabbit's foot was mentioned in literature as a way to ward off aches and pains. It shows up again in African American hoodoo, a combination of African folk legend and European tradition, and by the 20th century, had taken on a set of specific rules. For example, the left rear foot of a rabbit was luckiest. Better still was the left rear foot of a rabbit killed in a cemetery at midnight. It seems the rabbit's foot was a counterculture talisman, able to take the worst kinds of evil and subvert them by its very existence [source: Treadwell].
While people still carry rabbit's feet (often as a keychain), many nowadays are synthetic, which is certainly good luck for rabbits.