Kyle Ettinger was working at a hobby store when he picked up his first quadcopter — a tiny Nano QX weighing in at less than half a pound.

He mastered flying it, and then got a bigger drone. And then another bigger drone. Then came fighting the drones and building his own. Soon, Ettinger was considered by many to be the best drone fighter in the world.

Ettinger is only 16 years old, but he’s found success by getting to the heart of drone battling: Dream up something weird and make it real. Last year he surrounded his quadcopter with a spherical carbon fiber frame that kept other drones from touching it at all. A string dangling from its bottom dropped into other drones’ rotors to take them down.

This year he’s on the offensive. His drone shoots nets at its competitors with a cannon-like contraption. He carefully engineered the size of the nets and the best way to launch them.

Unlike drone racing, which has trended toward off-the-shelf drones made just for racing and carefully planned events, drone battling still has a Wild West feel. Each competitor starts with three points and loses one each time their drone hits the ground or becomes tangled in a net. Repairs are allowed between rounds. But that’s pretty much it for rules. Competitors build drones with goofy shapes or rely on their piloting skills to outmaneuver their opponent.

“The appeal of combat is so different than the appeal of racing,” said Marque Cornblatt, CEO of drone sports organizer Aerial Sports League. “Racing is a drug. On the other side of the equation is this engineering, mad scientist mindset where you want to make things. It’s the kid that grew up playing with Legos and Erector sets, now they want to fly and smash their Legos together.

A new model

Ramble down one of hills leading to San Francisco’s northern shore and you might come across the Palace of Fine Arts — a Greek-like temple that can offer a zen retreat from the city’s rumbling streetcars and tech rat race. There are swans and fountains, and now, if you listen closely enough, the buzz of a drone.

The Innovation Hangar that sits behind the temple has a new tenant: an arena dedicated to the emerging art of drone sports. Drone Sports World will offer drone lessons and flying spaces during the day, and a nightclub by night. There’s drinking and music, and tiny quadcopters moving at high speeds.

“It’s very sexy and dark and it looks like ‘Tron’ — kind of the future of underground drone racing,” Cornblatt said. “It’s got a little bit of sci-fi. It’s got a little bit of the blinky light aesthetic that you might find at Burning Man or any kind of EDM concert. Yet instead of standing there watching a DJ, you’re hanging out watching the most cutting-edge drone sports.”

Part of a complex originally built for the 1915 Panama-Pacific Exposition, the Palace and Innovation Hangar has been reinvented again and again as San Francisco boomed and busted, boomed and busted. The Hangar was once home to the city’s Exploratorium museum before becoming an office and popup event space. Now it’s dedicated to elevating the controversial drone.

Racing is a drug. On the other side of the equation is this engineering, mad scientist mindset where you want to make things. Marque Cornblatt, CEO of Aerial Sports League

If you look at fighting drones from a certain angle, they’re one step away from a weaponized UAV. They shoot things, they hit each other. Aerial Sports League faced a scare earlier this year when the California legislature considered banning weaponized drones — a phrase that, when overly broad, can include sport quadcopters.

Cornblatt says no one who attends an Aerial Sports League event walks away thinking of hobby drones as dangerous. But event organizers are rethinking how they can get around existing rules, which require drones to always be flown within line of sight and bans them from certain regions.

The easiest answer is moving their sports indoors. Cornblatt calls it the skate park model: Give people a space to fly, and they won’t be forced to fly illegally. San Francisco is mostly off-limits for flying drones, but now it has its own destination arena.

“The idea that we have a dedicated space for drones that’s indoors but big enough you can have all the fun and games you want, that’s kind of a first,” Cornblatt said. “San Francisco has an opportunity to be a template for how older cities and municipalities want to address the growing swarm of drones.”

Other countries are toying with the model, as well. Consumer drone maker DJI is about to open an arena in South Korea, where you can participate in workshops or fly through an LED-lit course.

While the spaces can cater to elite flyers who want sophisticated flying spaces or a practice arena close to home, they also represent a point of entry for newbies. Drone Sports World sells beginner drones, offers classes and can help pilots register with the government. It’s a hip, familiar space that can reach more people than ever before.

A rogue history

The Bay Area claims to have invented drone battling. Around 2010 — before anyone was thinking seriously about drone sports — Cornblatt and his friends started to get together in their homes and laboratories and play robot games. They would smash together toy drones and watch them shatter into pieces.

It sparked an arms race to build something that could survive a collision. They started meeting on Friday nights to show off quadcopters that shot flames or airsoft pellets. Their fight club slowly turned into a spectator event, and then a formal meetup. The technology improved. People branched out and started racing their drones, too.

From those early fight club meetups, it was possible to see drone battling’s draw. Drone racing is streamed online and on ESPN, but organizers have struggled from the start with adapting it to be a spectator sport. The aircraft are the size of a dinner plate or smaller and move at high speeds around enormous arenas. But in battling, they are right there on the other side of a net. They’re often brightly colored and put their creator’s ingenuity front and center.

“It uses all the senses,” pilot Justin Kelly said. “There’s crashes, there’s a lot of movement. It’s a chaotic dance almost. People come to watch that.”

Cornblatt’s group eventually decided to spread word of its ultra-tough drones with a Kickstarter. Videos showed them shooting it out of the sky with a shotgun. While quadcopter piloting had once been about being good enough to protect your drone, it was possible to push the limits of flying without worrying about smashing an expensive gadget.

Drone battling remains a relatively small community, but it’s growing. Pilot Andrew Dyson said someone new tends to show up to each event. Pilots are friendly with one another. So far, Drone Sports World has sold out every one of its expo events to spectators.

Creativity is king

Fighting is an unavoidable part of America’s relationship with robots. BattleBots taught us that they can be both violent and fun. When there are no rules, imaginations run wild. You can dream up a machine topped with three hammer arms and find yourself fighting a deadly spinning wheel. There are clangs and sparks, and audiences love it. Drone battling captures that same energy.

“I really like how they have kept the rules to a minimum to encourage engineering and freedom,” Ettinger said. “You’re not held down by a ton of rules so you can just do whatever you want and see what happens.”

It draws a totally different person than drone racing, according to Kelly. While pilots’ egos often get involved in the racing world, battling draws people who are willing to build something for no reason at all. They are makers and tinkerers who are okay with looking like their baby was hacked together from parts in a garage.

“It’s a different mindset. In the race world, it’s pristine. Everything’s got to be polished and perfect” Kelly said. “In combat, it’s PVC pipes and wood glue and zip ties and all that funky stuff, but it works.”

Dyson agrees. Building a battle drone tends to be an organic process for him. You want parts that are light, but effective. He tends to start with a body and then experiment with different parts. His drone shoots rubber bands.

Kelly takes a more deliberate approach. A 3D printing on-demand business owner by day, he’s known for the music-blasting King Koopa (AKA Bowser) shell that sits atop his drone. He says some people use battle events to test materials’ abilities and the design of new props and motors. You can quickly tweak your design between races or show up with something totally new.

Diversity of strategy is big as well. It’s common to jockey to stay higher up in the air than an opponent (that dangling string trick is popular), but in these early days, competitors are still inventing entirely new maneuvers. Kelly likes to watch military videos and work their piloting tactics into his battling strategy. Some of them work.

Both Dyson and Kelly say they fly to draw kids to the sport. Dyson has been flying model aircraft since he was 10. At the time, drones had remarkably fewer features. Without today’s sophisticated sensors, pilots had to do much more maneuvering by hand. Modern drones are cheaper and easier to use than ever before, making them accessible to many for the first time. It’s a powerful tool for exposing people to engineering and other STEM skills.

Ettinger already knows he wants to be a mechanical engineer. He’s learned about design, 3D printing and machining parts through drone battling, and he thinks others can too.

“You have to learn a lot of the stuff that engineers have to do, but you get a really fun result after, Ettinger said. “It can really bring them in with a fun attitude and the reward of getting to fight.”

So if you ever find yourself admiring the swans at the Palace of Fine Arts, consider stopping by the Innovation Hangar to learn something new about quadcopters. You just might be the sport’s next great pilot.