Dice probably arose independently in several regions, and so their exact origins are shrouded in mystery. But dice seem to be a staple of human ingenuity. "The idea to attribute values to the different sides of one object was, of course, a revolutionary idea," says archaeologist Ulrich Schaedler, director of the Swiss Museum of Games.
Let's take a closer look at that revolutionary idea with a brief history of dice.
Sticks, Stones and Knucklebones
When most people think of dice, they generally picture a six-sided white cube sporting one to six black dots on each side. But this hasn't always been the predominant dice template.
Ancient dice were often made of stick, shell or seed and most were two-sided, often with one flat side and one rounded side, like a shelled peanut. Sometimes the two sides were decorated with paint or carvings to further differentiate them. Two-sided dice were widely used by ancient peoples across the globe, from the Aztecs to Native Polynesians. Some modern cultures, like the Navajo Nation, still use them for traditional games.
Astragals, also known as knucklebones, are fascinating objects in their own right. As their colloquial name suggests, knucklebones are literal bones taken from the back ankle of a sheep, goat, deer, horse or other large, hoofed mammal. They have been used as four-sided dice since at least the fifth century B.C.E. by numerous civilizations, including Indigenous Americans, ancient Greeks and ancient Egyptians, who prized them so highly that they were sometimes buried with their favorite astragals. In Roman antiquity, each of the four sides was given a name corresponding to its shape: the belly, the hole, the ear and the vulture.
Tossing knucklebones is not a truly random process. Two of the sides — the belly and the hole — are much broader than the other two and are therefore more likely to come up. Ancient Romans assigned points accordingly. The broad sides were worth 3 and 4 points, while the ear and the vulture were worth 6 and 1 points, respectively. "They were aware of this different probability," says Schaedler, "So, good luck comes very rarely, but bad luck comes also very rarely."
"Dice changed over time from natural objects, such as shells and sticks or astragals, to manufactured objects," says Anne-Elizabeth Dunn-Vaturi, a researcher at the Metropolitan Museum of Art.
Today, plastic or metal versions of knucklebones are popular in some parts of Europe. But none of these dice resemble anything you'd find in a Vegas casino. So the question is: Where and why did dice become cubes?
Squaring Up and Squaring Off
The oldest known cubic dice date back to around 2500 B.C.E. and come from the Indus Valley, which encompasses much of present-day Iraq (as well as parts of Afghanistan, Pakistan and northern India). Scholars aren't quite sure what prompted people to use a six-sided shape, but they speculate that it probably had something to do with adding randomness — after all, a cube has more configurations than a four-sided astragal, which in turn has more configurations than a two-sided stick. Early cubic dice were made from clay or bone; later models were sculpted from marble, metal or even amber.
Even though these archaic dice were recognizably cubes, they still differed from the modern casino format. "Today, dice are almost always made with the opposite sides adding up to seven," says Jelmer Eerkens, an archaeologist at the University of California Davis. "But a lot of ancient dice are not in that configuration." A common arrangement in the pre-medieval Netherlands, for example, put 1 opposite 2, 3 across from 4, and 5 opposing 6. The modern "opposing sevens" configuration became standard sometime in the late Middle Ages.
Polyhedral dice (a term that includes our friend the cube) were used in many ancient games. In Rome, they were the basis for tali and tesserae — in China, they were critical pieces in liubo, a mysterious Zhou Dynasty-era game that also involved bamboo sticks, chips, ivory game pieces and a knife.
Of course, not all ancient dice were made for fun and games. Some had a much more serious purpose: foretelling the future.
When asked about quantum mechanics, Albert Einstein famously quipped that "God does not play dice with the universe." But it seems that the ancient Greeks and Romans would have taken issue with Einstein's proclamation; they believed that it was possible to divine the gods' will with a roll of the dice.
The name for this custom is astragalomancy, which derives from the astragals used by early practitioners. As time went on, however, manufactured dice became increasingly popular. The problem was, these dice weren't particularly random. "These Roman period dice, they're asymmetrical," says Eerkens, "they're six-sided dice, but they're not cubes." Many were elongated into rectangular prisms, or slanted toward one side.
But according to Eerkens' research, that might not have bothered Roman fortunetellers. "Because they thought the gods sort of controlled the outcome," he says, "it just mattered that all the different possibilities were present on a die."
Of course that reasoning wouldn't fly in a Vegas casino — under Nevada law, the penalty for gambling with asymmetric dice is one to five years in prison and up to $10,000 in fines. So, next time you find yourself at the craps table, maybe leave the ancient divination dice at home.