Why Romans Used Lopsided Dice

Roman-period dice are often non-cubic (i.e., asymmetric or lopsided). These lopsided dice often favored certain rolls, especially the numbers 1 and 6. Why were they made like this?
Why Romans Used Lopsided Dice

Dr. Jelmer Eerkens measures a modern Chinese die in the Archaeometry Lab of the Department of Anthropology

Recent research by UC Davis Department of Anthropology faculty member Jelmer Eerkens and his colleague, Alex de Voogt from Drew University, suggests that these dice are not “cheaters” dice, as some argue, but relate to the way Romans understood how the world worked. Romans did not believe dice rolls were random or dictated by probability, as we generally do today. Instead, they understood dice rolling to be controlled by gods, who either favored you or not in game play or divination. Therefore, in the Roman view, die shape did not affect die-rolling properties, and a lopsided die worked the same as a perfectly cubic one. Dr. Eerkens and his co-author measured Roman-period dice from the Netherlands, and conducted modern experiments on die-making with naïve die users to reach these conclusions. Their research was written up in a paper titled “Why are Roman-Period Dice Asymmetrical? An Experimental and Quantitative Approach”, which was published in June, 2022, in the journal Achaeological and Anthropological Sciences (https://doi.org/10.1007/s12520-022-01599-y)

Lopsided Dice
Two lopsided Roman-period dice from Woerden (left) and De Druppels (right) in the Netherlands.