When we sit down to play Yahtzee, backgammon, or any of the multitudinous games that rely on dice, we expect that these dice will be “fair,” or equally likely to land on any of their six sides. But probability wasn’t always a concern when it came to the roll of the dice. As Michelle Starr reports for Science Daily, a recent study analyzed dice dating from the Roman era to the 17th century and found that the ubiquitous little cubes have become increasingly uniform over time—and increasingly fair.
Researchers from the University of California, Davis, and American Museum of Natural History studied 110 dice from museums and archaeological depots in the Netherlands and compared them to 62 dice from the United Kingdom. They describe this intriguing evolution of dice over the centuries in a recent study published in the journal Acta Archaeologica.
The researchers found that dice made before 400 B.C., or during the Roman era, were large and typically adhered to the “sevens” configuration, with opposite sides adding up to the number seven (1-6, 2-5, 3-4). This is the configuration commonly used today, but unlike the symmetrical cubes that we know, Roman dice were highly irregular in shape. They were made from a variety of materials—like bone, metal and clay—and were often squished and lopsided. It is possible, the researchers say, that ancient Romans deliberately used irregular dice because they thought it would help manipulate the roll. But it might also be true that Romans weren’t particularly concerned about the shape of their dice, believing that the outcome of a roll was determined by fate.
Researchers are certain that the Romans’ wonky dice would have affected how the dice fell. “The majority of the asymmetrical dice have the 1 and 6 on opposite sides of the flattened cube in positions more likely to roll ‘up,’” they explain in the study.
Starting in 1100 A.D., dice became more standardized, which may suggest that European gamblers became increasingly concerned about rooting out players who tried to gain an advantage with unfair dice. The cubes got smaller, leading to a change in design. Previously, a die’s “pips,” or dots, were surrounded by two rings around them; in the 12th century, there was room for only a single ring. The configuration of dice also shifted to a numbering style popular in ancient Egypt and Mesopotamia, which saw opposing sides of a die add up to a prime number (1-2, 3-4, 5-6).
“We don’t really have a good idea why that [change] happened or what caused that shift, but we see it both in the U.K. and the Netherlands,” Jelmer Eerkens, an anthropologist at UC Davis and one of the authors of the study, tells Christina Ayele Djossa of Atlas Obscura, “So, it was something people must have agreed upon.”
During the Renaissance, dice underwent yet another significant change. Starting around 1450, they became less regular in size and pip style, but more standardized in symmetry and configuration, which shifted back to the “sevens” system. The increasing attention paid to symmetry in particular may have been driven by new knowledge of probability, a field of mathematics that blossomed during the Renaissance.
“A new worldview was emerging,” Eerkens says in a statement. “People like Galileo and Blaise Pascal were developing ideas about chance and probability, and we know from written records in some cases they were actually consulting with gamblers. We think users of dice also adopted new ideas about fairness, and chance or probability in games.”
While the evolving shape of dice may seem like a niche topic, knowing about these six-sided implements can be very useful to archaeologists and historians. For one, understanding changes in dice could help with the dating of archaeological sites, particularly if there is a scarcity of other materials that would be useful in dating.
Dice also offer insight into the transmission of knowledge throughout northwestern Europe. While ancient dice were quite irregular, later dice were standardized, suggesting either that there were a small number of die manufacturers, or that manufacturers were staying faithful to culturally transmitted rules about die production. Then, of course, the changing roll of the dice itself, suggests shifting worldviews in Europe.
“Gamblers may have seen dice throws as no longer determined by fate,” the researchers write in their study, “but instead as randomizing objects governed by chance.”