A new Colorado State University study presents evidence that the earliest known dice in human history were made and used by Native American hunter-gatherers on the western Great Plains more than 12,000 years ago – at the end of the last Ice Age and long before the earliest known dice from Bronze Age societies in the Old World.

Published in American Antiquity, research by author and Ph.D. student Robert J. Madden indicates that dice, games of chance and gambling have been a persistent feature of Native American culture for at least the last 12,000 years, with the earliest examples appearing at Late Pleistocene Folsom-period archaeological sites in Wyoming, Colorado and New Mexico. These artifacts predate the earliest known Old World dice by more than 6,000 years.

“Historians have traditionally treated dice and probability as Old World innovations,” Madden said. “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.”

To determine the artifacts as dice, Madden developed a checklist of physical features previously identified as dice by more recent historical analysis and applying this method to reclassify older artifacts that previously had been overlooked or misidentified.

Rewriting the deep history of probability

Historians of mathematics widely regard dice games as humanity’s earliest structured engagement with randomness, an intellectual precursor to probability theory, statistics and later scientific thinking. Until now, the origins of these practices were thought to lie exclusively in Old World complex societies beginning around 5,500 years ago.

This study suggests a much deeper and broader history.

“These findings don’t claim that Ice Age hunter-gatherers were doing formal probability theory,” Madden said. “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.”

What these Ice Age dice looked like

earliest examples identified in the study come from Folsom sites dating to roughly 12,800–12,200 years ago. Unlike modern cubic dice, these were two-sided dice known as “binary lots,” carefully crafted, small pieces of bone that were flat or slightly rounded, often oval or rectangular in shape, sized to be held in the hand and tossed in groups onto a playing surface.

The two faces of these binary lots were distinguished by applied markings, surface treatments, coloration or other visible modifications, much like heads or tails on a coin, with one face designated as the “counting” side. When thrown, they reliably landed with one side or the other facing upward, producing a binary (two-outcome) result. Sets of these dice were cast together, and scores were determined by how many landed with the counting face up.

“They’re simple, elegant tools,” Madden said. “But they’re also unmistakably purposeful. These are not casual byproducts of bone working. They were made to generate random outcomes.”

Primarily used by women, dice games were commonly used not only for entertainment but as a way to barter with other tribes, he added.

How the research was conducted

The study introduces a new, straightforward method for identifying ancient North American dice based on measurable physical features rather than subjective guesses. Madden created a checklist of specific attributes, developed by analyzing 293 sets of historic Native American dice documented by ethnographer Stewart Culin in his 1907 monograph, Games of the North American Indians.

Using this checklist, Madden revisited previously published archaeological records, examining artifacts that were once labeled as possible “gaming pieces” or overlooked entirely. By applying this clear, systematic approach, the research found that many artifacts previously ignored or misclassified were, in fact, dice. Madden identified more than 600 dice from archaeological sites across North America, spanning every major period of prehistory – from the end of the Ice Age to the time after European contact.

“In most cases, these objects had already been excavated and published,” Madden said. “What was missing wasn’t the evidence, it was a clear, continent-wide standard for recognizing what we were looking at.”

The earliest examples were examined directly in museum collections at the Smithsonian Institution, the University of Wyoming Archaeological Repository and the Denver Museum of Nature and Science.

A 12,000-year cultural tradition with living descendants

The research also documents the remarkable breadth, as well as the persistence, of Native American dice games. From Paleoindian times through the Archaic and Late Prehistoric periods, dice appeared at 57 archaeological sites across a 12-state region associated with a variety of different cultures and subsistence strategies.

According to Madden, this breadth of use and endurance reflects their social importance. “Games of chance and gambling created neutral, rule-governed spaces for ancient Native Americans,” he said. “They allowed people from different groups to interact, exchange goods and information, form alliances and manage uncertainty. In that sense, they functioned as powerful social technologies.”