Breaking Harmony Square: A game that “inoculates” against political misinformation

We present Harmony Square, a short, free-to-play online game in which players learn how political misinformation is produced and spread. We find that the game confers psychological resistance against manipulation techniques commonly used in political misinformation: players from around the world find social media content making use of these techniques significantly less reliable after playing, are more confident in their ability to spot such content, and less likely to report sharing it with others in their network.