The Library

Julian wanted to brush up on his Japanese and Spanish. The popular language learning app Duolingo, with its gamified incentives and rewards, its leagues, tournaments, and power-ups, seemed like a good way to do it. He started spending hours in the app, trying to claw his way to a better rank. That’s when he started noticing something odd: In Duolingo, ostensibly a learning tool first and foremost and not a competitive game, some users, for reasons Julian couldn’t fathom, seemed to be cheating their way to the highest ranks.

But first, a quick refresher on the massively successful app. Even if you aren’t one of Duolingo’s users, you are almost certainly familiar with its existence, or at the very least with its ubiquitous, vaguely threatening green owl mascot, which has over 6 million followers on TikTok. The app is tremendously popular, boasting 500 million learners and claiming to be the “world’s most downloaded education app.” At its core, it’s a simple language learning game that takes the user through lessons involving word matching, listening, speaking, and writing exercises. Duolingo offers over forty languages, and the base version is free, though there is a paid tier that offers additional learning opportunities, unlimited tries, and other perks.

One of Duolingo’s many gamification features are its “leagues”—competitive ladders ranging in rank from Bronze to Diamond that players are placed into and ranked in based on how many exercises and challenges they’ve completed that week. For reference, a single lesson that takes five to ten minutes will grant between 10 and 20 XP, without boosts or bonuses. A casual player might earn around 50 XP a day, and Duolingo generally gives a little extra in terms of gems or other rewards for reaching that. It’s in these leagues that Julian noticed something strange afoot.