AI Decodes Rules of Mysterious Roman Board Game Found in Dutch Museum

Rules of mysterious ancient Roman board game decoded by AI

It was the summer of 2020, and researcher Walter Crist was wandering around the exhibits inside a Dutch museum dedicated to the presence of the ancient Roman empire in the Netherlands. As a scientist who studies ancient board games, one exhibit stuck out to Crist: a stone game board dating to the late Roman Empire. It was about eight inches across and etched with angular lines that roughly formed the shape of an oblong octagon inside a rectangle. "I thought to myself, 'Well, that's very interesting,' because the pattern on it -- it's not something I had ever seen in the literature before," Crist says. What the game was called and how it was played were a mystery, too. If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Crist contacted the museum curators to get a closer look. And now he and his colleagues believe they've decoded the game in a first-of-its-kind study using a combination of more traditional archaeological methods and artificial intelligence. According to the analysis, the object appears to be a sort of "blocking game." In these types of games, one player tries to block another from moving; one example is tic-tac-toe. The research was published on Monday in the journal Antiquity. Crist, now a guest lecturer at Leiden University in the Netherlands, recalls that when he and his team started investigating the board game, they didn't have a ton of details to work with. They knew that the game board had been found around the late 1800s or early 1900s in the southeastern Netherlands' city of Heerlen -- which would have been the city of Coriovallum in Roman times. The board was made out limestone that was imported from France. And the game was likely played casually and may not have been particularly notable, in part because there is no known documentation of it in written texts from the time. To decipher the rules, Crist's team programmed two AI agents to play the game over and over again using more than 100 different sets of rules taken from other known European games, both ancient and modern. As the AI agents played -- 1,000 games per set of rules -- the researchers tracked how the pieces moved. Then they compared the moves with the levels of wear on areas of the board, tracing which gameplay seemed to replicate grooves on the stone. The team found nine rule sets that appeared "consistent" with the wear on the board. "And they were all variations of this same kind of blocking game," Crist says. This type of game was played in the 19th and 20th centuries in Scandinavia, and researchers thought it dated to early medieval times. But the Roman game is the earliest example of such a game in Europe, Crist says. He and his team called the game Ludus Coriovalli, Latin for "the game from Coriovallum." (You can play it online here.) Crist hopes the study will help researchers solve other ancient board games. Such games offer a way to connect the ancient past to our own lives, he says. Indeed, they haven't changed much over the centuries. The ancient Egyptian board game Senet, for example, might not have been all that different from Sorry! Chess, meanwhile, is thought to have originated in ancient India, and nobody really knows when or where backgammon originated. Understanding how ancient games might've been played, Crist says, "can lead us to new insights on how people in the past enjoyed their lives."

AI helps archaeologists solve a Roman gaming mystery

The researchers used virtual players to test possible combinations of pieces and moves An old, flattened piece of limestone inscribed with a crisscross of grooves looks like the board for a game, but for nearly a century, no one knew how the game was played. Now, researchers have used artificial intelligence to reverse-engineer the rules, revealing the board was probably part of a "blocking" game played by the Romans. The innovative approach to solving how the game was played had virtual game players run through more than 100 sets of possible rules. The researchers' goal was to determine which set of rules best created the wear patterns on the limestone, Leiden University archaeologist Walter Crist and his colleagues report in the February Antiquity. Archaeologist Véronique Dasen of Switzerland's University of Fribourg called the study "groundbreaking" and added that the technique could be used to investigate other "lost" games. "The research results invite [archaeologists] to reconsider the identification of Roman period graffiti that could be actual boards for a similar game not present in texts," she says. The board, just 20 centimeters across, was found in the Dutch city of Heerlen and put on display in a local museum. Heerlen sits atop the ruins of the Roman town of Coriovallum. The board's archaeological context is unknown, and there are no records of such a game from Roman times, which lasted until the fifth century in this region. Given the board's size, the game probably had only two players. The researchers used the AI-driven Ludii game system to pit the two virtual players against each other in thousands of possible games, derived in part from the known rules of later games. Ludii uses a specialized "game description language" to drive its virtual players; in this case, the games were designed to test different configurations of pieces and moves so that the researchers could determine which rules might have produced the wear patterns. "We tried many different kinds of combinations: three versus two pieces, or four versus two, or two against two ... we wanted to test out which ones replicated the wear on the board," Crist says. The game, called Ludus Coriovalli, or the "Coriovallum Game," can now be played online against a computer. The result suggests that, on limestone at least, one player took turns placing four pieces in the grooves against an opponent's two. The winner was the player who avoided being blocked the longest. Blocking games like this weren't thought to have been played in Europe until the Middle Ages, Crist says. Go and Dominoes are modern blocking games, but Ludus Coriovalli doesn't resemble either of those. Some archaeologists of games say the study is the beginning of a breakthrough. "If more were known about the board's context and potential game pieces, more interpretations could be made of how it functioned in past social life," says University of North Florida anthropologist Jacqueline Meier, who was not involved in the research. Dasen also wasn't involved but led the Locus Ludi project to study ancient Roman and Greek board games and other forms of play. She says blocking games were once popular in Europe and that their names in several languages indicate they were often likened to hunting. But there had been no evidence until now that the Romans knew of this type of game, she says. "Games can go on for centuries, and sometimes they appear and then disappear."

Dueling AIs Reconstruct Rules of Mysterious Roman-Era Board Game

In the hands of a non-expert, the oval artifact doesn’t look like much of anything. However, geometric patterns on one of its two broad sides, along with other clues, suggest it to be a stone board game. In a study published today in the journal Antiquity, researchers used artificial intelligence to test this theory, as well as identify what the game rules may have been. Those who came before us enjoyed board games, just like we do; the pastime dates back to the Bronze Age, at least. The problem, however, is that the components of many of these games were not nearly as enduring as Monopoly’s houses and hotels will surely prove to be. As such, the stone object that came to light in Coriovallumâ€"a Roman town in modern-day Netherlandsâ€"could be a rare opportunity to investigate ancient nerds. “We identified the object as a game because of the geometric pattern on its upper face and because of evidence that it was deliberately shaped,†Walter Crist, lead author of the study and an archaeologist at Leiden University specializing in ancient board games, explained in an Antiquity statement. “Further evidence that it was a game was presented by visible damage on the surface that would be consistent with abrasion caused by sliding Roman-era game pieces on the surface.†There’s only one problem. The aforementioned geometric pattern doesn’t align with any game known to researchers. To investigate the matter, Crist and his colleagues did what many people faced with a question tend to do these daysâ€"they asked AI to give it a go. Given the artifact’s human-caused abrasions, the team used AI to model potential game rules. “The damage was unevenly distributed along the lines of the board,†Crist said. “We sought to answer the question of whether we could use AI-driven simulated play as a tool to discover playing rules that would replicate this disproportionate pattern of use wear on the surface of this board with rules similar to those documented for other small games in Europe, thus confirming that the object was likely to have been a game board.†The researchers had two AIs play a large number of ancient European board games, including Scandinavia’s Haretavl and Italy’s Gioco dell’orso, until they landed on one that could have caused the stone board’s wear-and-tear. This approach ultimately revealed a match with blocking games, a kind of board game whose objective consists of blocking the other player’s movement (just like Ticket to Ride, if you play like my fiendish partner). It also bolsters the preexisting theory that the artifact was a board game after all. “This is the first time that AI-driven simulated play has been used in concert with archaeological methods to identify a board game,†Crist concludes. “This research provides archaeologists with the tools to be able to identify games from ancient cultures that are unusual or uncommonly played, since current methods for identification rely on connecting the geometric patterns that make up the playing surface to games that are known today from references in text, or from artistic representations of them.†Interestingly, previously known traces of blocking games only appeared in Europe starting in the Middle Ages and are overall very rare in the region. In other words, the study suggests that people may have played these types of games centuries earlier than researchers thought. All that’s left to discover is how many tears were shed and friendships broken over the movementâ€"or notâ€"of pieces on this board.