"Teachers already want to use these games in the classrooms," Levin said. He and his colleagues work to make the software more intuitive and suited to their needs so that teachers—and students—can use the games in classrooms and have fun while they’re at it.

Levin, now 40 with a sandy beard, glasses, and ponytail, first played an early version of Minecraft with his 5-year-old daughter in 2010. He was amazed at how much his daughter was learning from Minecraft; she solved problems on her own, developed a spatial understanding in the game, and accelerated her reading and writing skills because she wanted to be able to interact with other players, he said. At the time, Levin was teaching technology classes at a private elementary school in New York City, so he decided to try out some Minecraft lessons with his second graders. As a self-identified "gamer" who worked with an Internet service provider before the dot-com bubble burst, Levin saw that teaching with Minecraft combined his interests perfectly.

The segment that involved Minecraft was intended to last a week, but Levin used the game for the rest of the semester, teaching students to type by allowing them to communicate with each other in the game and showing them how to do online research by trawling the vast Minecraft forums for specific information. But getting there wasn’t easy; Levin spent a lot of time customizing the game to fit his instructional needs. Minecraft is an open-ended game with a never-ending landscape and digitally rendered resources. In certain game modes, players have to gather resources to craft shelter, tools, and armor to meet basic needs and survive battles with one another. But the part that players seem to enjoy the most is the construction element, in which they build entities like functional computers or reconstruct landscapes such as the entire country of Denmark. Given how versatile the game is, it’s understandable that Levin wanted to restrict some of these capabilities to give his students a safe, age-appropriate experience. He modified the code so that kids weren’t able to fight with one another in the game, and he limited some of their geographic range so that they could find their way back to a central location where they had a building just for their class to use. He wasn’t yet plugged into the online community where teachers were sharing similar modifications to the game, so he coded it all himself.

But it was worth it. Levin’s students learned more than just the hard skills he had intended for them to they pick up—they were also having profound discussions about topics that were notoriously challenging for teachers to communicate effectively. "It led to conversations in the classroom about how we treat these virtual spaces that we all find ourselves in, especially the young people that are coming into this complicated world of social networking," Levin said. "Are we going to treat our class’ Minecraft world as an extension of our classroom? Do the rules that apply in the school building also apply on our Minecraft server? What happens if someone breaks those rules?" These were lessons in what Levin calls digital citizenship, which were typically being taught in middle school, once students were already deeply embedded in social networks, but not yet in elementary school when they were just starting to use them and the lessons would be most useful. "There was just so much to do and the game was so malleable that I kept being able to bring in all the things I needed to teach in the game," Levin said. He started a blog to share his experiences with other teachers, and it went viral, making its way to the front page of Reddit.