Last year, Nicholas Mulder, a history professor at Cornell University, asked his Twitter followers to help him understand a certain kind of student in his classes: players of the video game Europa Universalis. Students kept enrolling in his course on modern Europe because of the game, which he had only recently learned existed. Bret Devereaux, a history professor at the University of North Carolina, saw Mulder’s tweet as an opportunity to explain a new phenomenon.

Devereaux plays Europa Universalis and likes it. But the fact that video-game developers, rather than professional historians, were responsible for shaping so many young people’s understanding of history deserved greater examination, he thought. The games made by Paradox Interactive, the Swedish studio that produces Europa Universalis, are among the most popular strategy titles in the world. Millions of people own the games, which allow players to take control of a historical nation or individual and guide the course of history. The average Europa Universalis player spends hundreds of hours on it. Some spend thousands.

Spending that much time engaged with any sort of historically themed content will affect one’s understanding of history. And yet to many players, exactly what they’re learning from these games remains a mystery. Devereaux aimed to correct that problem. Academic historians, he wrote in a four-part post on his blog, must now grapple with a new breed of students “for whom Paradox is the historical mother tongue and actual history is only a second language.” Prompted by Mulder’s confusion, Devereaux hoped to illuminate the historical assumptions that underlie the games.

“Some time ago, we passed the line where historical video games are at the same level of influence and demand the same level of critical analysis” as historically themed movies or TV shows, Devereaux told me. But despite the fact that the PC-gaming industry is now twice the size of the movie industry, many games have evaded such analysis.

Analyzing video games is particularly difficult for two reasons. First, their influence is hard to track: Teachers may not even notice that the student asking why the Ottomans didn’t colonize America or what happened to Burgundy may have a view of history that was molded by Paradox games. “The student in your class that knows what Prussia is is the student that played Europa Universalis IV,” Devereaux said. And second, unlike other cultural mediums, “games are about systems; they’re about the mechanics,” Devereaux told me. Those systems and mechanics are how video games can “teach” people history. The presence of such mechanics, though, does not mean that players will necessarily understand them. “The major challenge is getting players to recognize and think explicitly about these systems,” Marion Kruse, an assistant professor of classics at the University of Cincinnati and a dedicated gamer, told me.