In general, drones are really expensive. They’re also loaded with complex and delicate technology: sensors, cameras, GPS antennas, and radios.

So with all that in mind, why would you want to intentionally bash them into one another? Repeatedly? In midair?

Well, because it’s a hell of a lot of fun to watch. The Aerial Sports League (ASL) sees drone combat as a sport, and one that’s just as fun for spectators as it is for competitors. The ASL, which hosts drone combat, drone racing, and freestyle demos at events across the US, was born out of a Kickstarter campaign in early 2014. But these battles aren’t recommended for your $1,000-and-up DJI Phantoms and 3DR Solos. That initial Kickstarter campaign was created to sell a nearly indestructible “Game of Drones” airframe and battle-drone kit.

The military-grade polymer airframe is impact-, fire-, and even shotgun-resistant.

The airframe alone costs $140, and it’s built to take a serious beating: The “military-grade” polymer airframe is impact-, fire-, and even shotgun-resistant. A full kit, which consists of the airframe, the motors, the speed controllers, the flight and power boards, and four propellers, costs about $400.

When they’re assembled and crashing into each other, these drones are so durable that they’re more of a danger to humans than to each other. They can smash into one other (and the ground) without incurring any damage other than a broken propellor or two, and competitions involve battling it out in a 30-by-30-foot, 25-foot tall netted “pit.” The drone operators need quick reflexes on their feet as well as the drone controls; they’re right there in the pit with the UAVs, and they often need to duck and dodge the drones as they’re careening toward them out of the sky.

The rules are simple. Each drone starts a battle with three points, and there is no set number of rounds. If a drone hits the ground or becomes tangled in the netting and stays there, it loses a point. If both drones get grounded after a midair collision, it’s a push and neither competitor loses a point. Once a drone reaches zero points, it loses the battle.

After a drone is grounded, each operator becomes a fast-acting pit crew. Pockets loaded with extra propellers, pliers, and zip ties, they have 90 seconds to repair their drone and get it back up in the air for the next round. That usually involves replacing a propeller, but in case they need to do deeper work, the Game of Drones kit involves a little pop-top that gives them access to internal components quickly. Similarly, the frame is held together with zip ties for quick repair.

The Aerial Sports League is based in San Francisco, but CEO Marque Cornblatt, Lead Designer Eli D’Elia, Lead Engineer Reiner Von Weber, and a handful of drone warriors recently visited New York for a combat session at World Maker Faire New York. Watch the video above to see their UAVs duke it out, and visit the ASL’s Events page to see if they’re coming to your neighborhood anytime soon.