WYOMING, COLORADO AND NEW MEXICO — A paper published in the journal American Antiquity in 2026 presented evidence that Native Americans were using two-sided dice in games of chance more than 12,000 years ago, predating the earliest known Old World dice by millennia. The findings, authored by Colorado State University graduate student Robert Madden, challenge the view among historians that dice and probabilistic thinking originated in the Old World.

The oldest dice artifacts identified in the paper came from Folsom deposits in Wyoming, Colorado, and New Mexico, dating to the end of the last Ice Age. The origins of probabilistic thinking had previously been traced to the Old World Bronze Age, roughly 6,000 years ago, meaning the Native American artifacts are about 6,000 years older than previously recognized examples.

"What the archaeological record shows is that ancient Native American groups were deliberately making objects designed to produce random outcomes and using those outcomes in structured games, thousands of years earlier than previously recognized," said Madden.

The early Native American dice were rudimentary, two-sided objects typically described as binary lots and were common to virtually every Native American tribe. Archaeologists had previously traced the use of such dice back 2,000 years but had been hesitant to conclude that older artifacts served the same purpose.

To make his case, Madden drew on a method common in archaeology — ethnographic analogy, which involves comparing artifacts to historically documented objects from the same area and cultural context to infer their usage. His primary resource was an 809-page report titled "Games of the North American Indians," published in 1907 by ethnographer Robert Stewart Culin. The report, based on the collection at the Field Columbian Museum of Chicago, included over 1,100 illustrations and descriptions of 239 sets of dice from 130 different tribes.

Using Culin's report, Madden developed four diagnostic criteria for identifying Native American dice. The criteria required artifacts to have two distinguishable sides, fall into one of four shape categories — flat, plano-convex, convex-concave, or convex-convex — and be of a size and shape suitable for hand-casting. Objects with drilled or pierced holes were excluded because they could be beads or decorative items, and artifacts whose two sides could only be distinguished by shape without clear markings were also excluded. Applying this method, Madden identified 565 Native American dice from 45 archaeological sites and designated an additional 94 artifacts as probable dice.

"These games are one-on-one; there's no house," Madden said. "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."