(NYTIMES) - Leaf Town started in the autumn, during recess. To reopen for in-person learning, the small elementary school had adopted new protocols to prevent the spread of Covid-19, and one of those meant that the playground equipment in the nearby park was off limits. With their recreational routine disrupted, the children were briefly at a loss.

Then some of them piled up fallen leaves to outline the walls of a small room. They named it the Everything Store, and they began transacting commerce: purely imaginary at first, then increasingly real.