Madden was able to conclusively identify 565 Native American dice from 45 different sites and designate an additional 94 artifacts as “probable” dice. Objects with a drilled or pierced hole were excluded from his assessment because they could just as easily be beads or other decorative objects rather than dice. He also excluded objects whose two sides could only be distinguished by shape, with no clear markings, for similar reasons. The oldest artifacts, from Folsom deposits in Wyoming, Colorado, and New Mexico, date back to the end of the last Ice Age, some 12,000 years ago.

According to Madden, dice and gaming in these societies weren’t anything like contemporary gambling, where the house always has the edge; rather, they likely served a social function.

“These games are one-on-one; there’s no house,” said Madden. “It’s a fair game, everybody’s got an equal opportunity, equal conditions, and it was used as a form of exchange, particularly between groups of people who did not come into frequent contact with each other, so they didn’t really know each other. It’s really a form of gifting over time that creates enduring reciprocal relationships. It’s not about a commercial transaction where you and I are going to swap something and then go our separate ways.”

The findings also shed light on early Native American concepts of probability. “When we see the origins of dice, we’re literally seeing the origins of probabilistic thinking,” said Madden. “That’s always been thought to have begun in the Old World, in the Bronze Age, about 6,000 years ago. This research shows that Native Americans were making dice, generating random outcomes and using those random streams of probability and harnessing them in games of chance 6,000 years earlier. So, if we want to understand the history of probabilistic thinking, we now need to look into the Old World at the end of the last Ice Age.”

That said, “These findings don’t claim that Ice Age hunter-gatherers were doing formal probability theory,” Madden added. “But they were intentionally creating, observing, and relying on random outcomes in repeatable, rule-based ways that leveraged probabilistic regularities, such as the law of large numbers. That matters for how we understand the global history of probabilistic thinking.”

American Antiquity, 2026. DOI: 10.1017/aaq.2025.10158 (About DOIs).