How 'Hearthstone's Here Comes the BOOM Was Built (Exclusive)

The 1900s cartoonist Rube Goldberg was best known for his illustrations of over-the-top machines, complex contraptions designed to do simple things, requiring dozens of steps involving levers, gears, balls and sometimes animals. Following Goldberg's example, aspiring mad scientists have been creating increasingly elaborate and ridiculous devices ever since.

Hearthstone's The Boomsday Project expansion is all about the chaos, destruction and creativity stemming from the desire for scientific exploration. To bring this idea to life, Blizzard brought on the best in the Rube Goldberg business: the production team at Slash Dynamic and the "League of Extraordinary Nerds" over at Synn Labs, whose mission is "to design and construct visually dynamic spectacles." President Adam Sadowsky was a child actor-turned-director who helped create the device for OK GO's music video for "This Too Shall Pass," which took more than 60 tries to perfect. He's since built machines for Red Bull, ESPN and more. He even created a 17-step machine for Google to drop an olive in a martini glass.

"I'm fascinated by engineering," Sadowsky told Newsweek. "I love odd, interesting uses of technology. There's something about the Newtonian physics, really basic stuff, that's approachable but allows me to express creativity."

Sadowsky dreamed up a host of crazy ideas to honor Hearthstone 's Dr. Boom, but had to figure out how to bring them to life. Testing was the most dangerous part of the planning process. The Boomsday Project explores the hazards of science unchecked, so the team at Synn had to go a little crazy. Originally, the team planned to drop a vial of sulfuric acid into a vat of sugar, which would create a carbon snake and push a lever. There were two reasons it couldn't work: the whole process takes four minutes and filling a poorly ventilated studio with poisonous gas wasn't really practical.

Another idea: ignite a ball of steel wool catch and use it to spray sparks. Turns out, that's a lot easier in theory than in practice. Originally, Synn tried to spin the object horizontally, but quickly concluded that spraying flaming metal flakes across a room full of expensive camera equipment was too risky. They eventually decided to use a handheld steadicam to shoot a 14-step machine that would reveal itself to be a Hearthstone game board.

Once the testing phase was complete, Synn created concept art and sent it over to Blizzard for approval. Ten days later, Slash Dynamic locked down Studio 60 in Downtown L.A., assembled a full team and started building.

Sadowsky assembled quite a team. There's self-proclaimed Rube Goldberg machine expert Zach Umperovitch, who has been creating the devices from a young age, competing at college competitions at Purdue. There, he created a 300-step machine that fit inside a six-foot cube, earning a Guinness World Record. Then there's Matt Gaulden, a sculptor who specializes in creating wire frames for rolling balls. Combine them with director of photography Jeremiah Pitman, an army of designers, who created a floor-size version of the Hearthstone game board, pyrotechnicians who could properly contain fires and an army of PAs, and you have a recipe for organized chaos.

"I collected a group of people who could capture my visions," Sadowsky said. " It takes a certain type of person who will adjust a trampoline half a centimeter at a time for hours to make the bounces work."

The general consensus, or hope, was the team would be able to nail the shot on the third try. "I'm pretty optimistic and believe that we can can get it on try number two, but mother nature is the boss here." Sadowsky said. "I consider myself a bit of a control freak, but once we start rolling, I'm in the passenger's seat."

Inevitably, things went wrong.

Trampolines of DOOM! Blizzard


Building a Rube Goldberg machine is not all explosions and gyroscopes. Like most jobs, it can be tedious, repetitive and stressful. Halfway through the last day of testing Sadowsky, sweat dripping down his brow, frantically talked to his crew while he scrutinized the final shot on the monitors from his director's chair. After hours of testing, there were a litany of new problems. The ice block in the middle of the machine would only move fast enough to hit the lever if it was between 18 to 20 pounds, but the heat of the studio was melting it faster than anticipated.

There was also a problem with the flaming tennis balls meant to bounce on a trampoline. "We run out of balls and the game's over." Sadowsky cautioned. "So how many times you want to play with the machine?"

The crew was quite literally burning through their supply of tennis balls, one of which needed to be set aflame and bounced on three separate trampolines for each test. The trampolines were going to be covered in lighter fluid and ignited, launching the tennis ball into a vat of propane bubbles.

"A new one works every time. I hate saying that because it's a six-dollar ball," Umperovitch said. If the ball became too charred, it would start to split, spilling out a precisely measured amount of sand, calculated to the exact gram.

"Whatever. If we need a dozen balls, we need a dozen balls," Sadowsky said, utterly focused on turning his vision into reality. "Can we have an extinguisher ready, instead of you guys blowing on them to put them out immediately? Let's save a ball if we can."

By the end of the day, they settled on using a new ball every machine reset.

soap bubbles
Soap bubbles and fire are truly terrifying Blizzard


The final day of shooting started at 6:45 a.m., with Hearthstone's marketing team in attendance watching every well-funded move. With DMX's "X Gon' Give It To You" blasting from the speakers (replaced with a new soundtrack in post-production), the custom-made aluminum ball was finally ready to roll. Its task was simple: travel along a metal railing, activate the flaming steel wool and knock over the ice block. This block would hit a button, knock a rag into the flames that then sets the tennis ball on fire. The flaming ball would bounce off trampolines into a metal bucket, drop into a vat of propane and, after lots of fire, activate a lever. This lever releases a bowling ball which rolls along and activates propane cannons as it goes toward the eventual finale of three rockets zooming across a track and activating a tesla coil. Simple right?

The tesla coil, the final piece of the puzzle, proved to be impractical and dangerous, so the team elected to add it in post-production.

The first run Sadowsky botched by failing to knock the ball with enough force, so those on set said "it didn't count." The second attempt went a lot better, but the rockets didn't go off right. As the team predicted, try number three was the winner, even with only one of the three rockets working as expected. Dr. Boom is all about janky equipment that just happens to work, making it feel perfect for the expansion.

After dozens of more "just in case" takes, sound recordings and injuries, the day was finally over. Standing for more than 10 hours a day, grabbing flaming objects and flirting with danger: all in a day's work for a mad scientist. "I had to change my socks three times because of the amount of blood in my shoes," Umperovitch said with a smile on his face.

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