A smooth, white limestone stone dating back to the Roman era, discovered in the Netherlands and long considered a mystery by archaeologists, may have finally been solved—with the help of artificial intelligence. The circular artifact, housed at Het Romeins Museum in Heerlen, features a network of straight and diagonal lines etched into its surface. For years, researchers were unsure of its purpose—until new technology provided a breakthrough. Using 3D imaging, archaeologists led by Walter Crist from Leiden University analyzed the stone and found that some lines were deeper than others, indicating repeated movement of game pieces. “We can see wear along the lines on the stone, exactly where you would slide a piece,” Crist explained, suggesting the object was used in a board game. Researchers at Maastricht University then turned to an AI system named Ludii, designed to infer the rules of ancient games. The program was trained on the rules of around 100 known ancient games from the same region. It generated dozens of potential rule sets and then simulated gameplay, identifying a few variants that were not only logically consistent but also engaging for human players. By comparing these AI-generated rule sets with the physical wear patterns on the stone, scientists narrowed down the most plausible game configuration. The resulting game appears to be a strategic, two-player contest where the objective is to trap the opponent’s pieces in as few moves as possible. The researchers describe it as “deceptively simple but thrilling strategy game.” Despite the promising results, Dennis Soemers from Maastricht University cautioned against overconfidence. “If you present Ludii with a line pattern like the one on the stone, it will always find game rules. Therefore, we cannot be sure that the Romans played it in precisely that way,” he said. Still, the findings represent a significant step in understanding ancient Roman recreational culture. The study, which includes a detailed reconstruction of the game’s possible rules and structure, has been published in the journal Antiquity. The discovery highlights how modern AI tools can help unlock secrets buried in ancient artifacts, offering new insights into how people played and thought thousands of years ago.