It’s incredibly easy to hack your neighbourhood playground for competitive sports. Here, a rock and a set of swings are the required elements for the intensely competitive “Ishi-tori ge-mu” (Grab the Rock Game).

How to Play: Get a rock. Place it somewhere where you think your opponent can’t reach. When he picks it up, he does the same to you. Ad infinitum. Superb afternoon fun.

Q: What fun and camaraderie might result from creatively combining multiple mundane elements of city infrastructure?

The video after the photos shows two boys teaching their younger friend how to play. The other videos offer a brief glimpse of the game in action.

Players: Girl, 6; Boys, 7.
Materials: stone, swing.
Concepts: together, competitive, coordination.