It’s hard to say exactly why children with autism are some of the greatest devotees of Minecraft, the computer game in which you build endless worlds out of Lego-like blocks. Stuart Duncan, a father of two, believes it’s because it’s a perfect union of two opposites. On one hand, Minecraft offers structure—everything from the water to the doors to the falling lava behaves with a certain predictability that they need. On the other hand, it gives the player infinite freedom. There’s no story, no levels, no bosses presenting participants with quests to complete. Behind the shield of their computer screen, players can do whatever they want to do in a sensory-friendly space—recreate the Taj Mahal, light up a house with torches, or hide in a cave.