“Alternate reality game” is the term du jour for what used to be called “playing make-believe with your friends outside.” The main difference is that ARGs are designed by professionals, aimed at adults, and usually harness the Internet and mobile phone technology to create their fantasy worlds as virtual “layers” over the real world. Run an Empire is a new ARG app that challenges you to conquer territory and defend it from rivals, rather like the classic strategy game Risk –but the territory is your own neighborhood, and the only way to conquer it is to walk or run around it with your own two feet.

“Strategy games have traditionally challenged players to out-think and out-maneuver one another,” says Ben Barker, who co-created “Run an Empire” at PAN Studio in London. “What’s incredibly exciting for us is the potential to see this mechanic played out away from screens and keyboards, playing pieces and dice rolls-–where the game board is overlaid on the world around us.”

A motivated 80-year-old with a cane could totally trounce a lazy twenty-something.

You don’t have to literally run to run your empire, but the incentive for physical activity is baked into the game. You can walk around the block to claim it as yours–but anyone else can take it away from you by doing the same thing. To fortify your borders, you have to encircle your territory regularly, not just once. “We want to reward effort and hard work over natural ability, and this means encouraging a play style based on sustainable and frequent activity, rather than speed,” Barker explains. What this means is that a motivated 80-year-old with a cane could totally trounce a spry-but-lazy twenty-something. How awesome is that?

Oh, and you can’t cheat by driving, skating, or cycling around your territory either–the app is programmed to use your phone’s accelerometer to flag any “unrealistic gait.” Just don’t call it a gamified fitness app. “We love the idea that the game will encourage people to get outside, be active, and see the space around them as something they can engage with, while not being primarily a health app,” Barker says. But he happily admits that increased fitness may be a likely side effect of playing outdoors. And that might be Run an Empire’s best feature–it’s designed to be something you want to do because it’s fun, not because you should. Go out and conquer.

[Read more about Run an Empire]