Researchers have finally decoded the rules of an ancient Roman game board excavated in the Netherlands. By combining detailed 3D scans with artificial intelligence simulations, a team from Leiden University and Maastricht University reconstructed how ancient players moved pieces across the limestone slab.
Decades of Mystery Surrounding the Coriovallum Limestone Board
More than a century ago, a scratched-up slab of limestone was unearthed in the modern-day Dutch city of Heerlen. The artifact sat in the Het Romeins Museum, which focuses on the local history of the Roman Empire’s expansion into Northern Europe during the first century. For generations, the object was recognized as an ancient game board, but its rules remained entirely unknown.
Walter Crist, who researches ancient games at Leiden University, first encountered the carved limestone in 2020. They had this thing that they were calling a game,
Crist recalled. Recognizing that the oval-shaped stone featured a distinctive chiseling pattern unlike other known artifacts, he set out to investigate whether people had actually played on it.
Examining the artifact from a specific angle revealed distinct wear marks. These physical indicators proved that players had repeatedly slid hard game pieces over the rock in consistent patterns, confirming its purpose despite the total absence of written rulebooks or historical records.
Using Artificial Intelligence to Reconstruct Ancient Rules
Because no written instructions survived from Coriovallum—the Roman village upon which modern Heerlen was built—researchers turned to modern computational tools to test possibilities. Luk van Goor of the local conservation business Restaura produced extremely detailed 3D scans of the limestone board. These digital models revealed that certain incised lines were a fraction of a millimeter deeper than others, indicating heavier usage.
With precise wear data in hand, the team utilized Ludii, a general game-playing system and database. Dennis Soemers, a computer scientist at Maastricht University, explained the training process for the system.
We trained Ludii with the rules of about a hundred medieval or older games from the same cultural area as the Roman stone. Ludii produced dozens of possible rule sets. It then played the game against itself and identified a few variants that are enjoyable for humans to play.
Dennis Soemers, Maastricht University
The research team programmed two artificial intelligence bots to play on a digital version of the limestone board, testing more than 100 distinct rule sets drawn from comparative European games. The bots completed 1,000 rounds for each variant, allowing scientists to track piece movements and isolate viable rules.
Placing the Discovery in Context
Board games have persisted across nearly all human cultures since at least the Bronze Age, which began around 3000 B.C.E. However, many early games vanish from the archaeological record when written explanations fail to survive. Barbara Carè, an archaeologist at the University of Lausanne who was not involved in the study, noted that researchers often look to game families with shared traits to understand how past pastimes evolved.
While games like Senet in ancient Egypt or the Royal Game of Ur left behind archaeological clues, others—such as the Roman duodecem scripta table found in Turkey’s Ephesus Museum—remain difficult to interpret due to missing instruction manuals.