Video game characters can start from humble roots before becoming stars. Mario was once a more generic hero called Jumpman who starred in a game named after his enemy, Donkey Kong, and this came after Nintendo lost the rights to make a Popeye arcade game. And now the star of Hearthstone’s next expansion, The Boomsday Project, continues the inventor goblin Dr. Boom’s journey from a random World of Warcraft enemy to a cover star.
Card games are an important and growing market in video games worth $1.3 billion in 2017, research firm Superdata reports. It should hit $1.7 billion in 2019. Hearthstone makes 3.3 times more than its closet competitor, and expansions give players a reason to keep spending more money on preorders, hero skins, and card packs. And to keep players interested (and attract new folks), The Boomsday Project will add 135 new cards when it launches on August 7, including legendary spells for each class and the new Magnetic keyword. Magnetic minions can attach to Mech cards to increase their stats, but you can also just play them like a normal minion.
But new sets aren’t just about cards. Expansions have themes, using World of Warcraft’s history and settings for inspiration. We’ve seen sets based on famous characters like The Lich King and Medivh. Next to them, Dr. Boom is a nobody. In World of Wacraft, he’s just some goblin you’re sent to kill as you’re leveling through the game. But then he appeared as a card in Hearthstone’s first full expansion, 2014’s Goblins vs. Gnomes.

Above: Dr. Boom.
This card became one of the most powerful minions the game has ever seen. It helped propel Dr. Boom into a recognizable character. We went into almost every deck from that era, earning the nickname “Dr. Seven” because he’d come out on Turn 7 in so many matches.
GamesBeat talked with Mike Donais, Hearthstone’s principal game designer, and visual effects artist Hadidjah Chamberlin about Dr. Boom’s new starring role, his rise in popularity, and the inspiration for The Boomsday Project. Specifically, why Dr. Boom has set up shop in the splintered, magic-filled land of the Netherstorm.
GamesBeat: Dr. Boom has gone from an enemy in World of Warcraft to a popular Hearthstone card, but how did that lead to him getting his own expansion?
Mike Donais: We went to him in the Netherstorm and asked him what he wanted to do with his life. He was like, “When I grow up, I want to be a mad scientist. He said he was well on his way. He was making the explosives and the bombs. But he wanted to be bigger.” He wanted to really contribute to the world. So he made this mad science [lab], floating in the Netherstorm, almost like an island. It’s got all these labs doing all kinds of different things. Each of the labs is headed up by one of the classes, and the mad scientist from that class, and he’s basically living his dream.
GamesBeat: A lot of people hated Dr. Boom in Hearthstone when he was eligible in Standard. He was so strong that you saw him in almost every deck. Then when he rotated into Wild, people missed him. Has his popularity surprised you at all?
Donais: Yeah, when he was in WoW, he was kind of a side NPC.
Hadidjah Chamberlin: A little tiny quest boss, I think?

Above: Dr. Boom as he appeared in World of Warcraft.
Donais: Now he’s kind of a hero, a hero of our story.
Chamberlin: He’s the Warrior’s hero, too.
Donais: Yeah, he’s a Warrior card, the Warrior scientist effectively. He has this awesome new environment. I don’t know if you saw the art he has. But he doesn’t really know how to control it. He’s trying to figure that out.
GamesBeat: This is the first new mech-based expansion since the first expansion, Goblins vs. Gnomes. Was that a starting point for designing the set, that you wanted to do mechs again?
Donais: People liked mechs, and it’s been a long time since we did mechs. Certainly, one of the things we’re always doing in Hearthstone — what mechanics do people like? When should we bring them back? People really liked Webspinner, so we made Babbling Book. We noticed that people liked Discover [where you play a card and then find a new card], so we made more Discover. People liked mechs so we brought back mechs, and so on and so forth.
We’re always trying out things, seeing what people like and don’t like, and making more of what people liked. When people liked Reno Jackson (who heals you to full health if you don’t have an duplicates), we added Kazakus (who gives you a special spell if you have a singleton deck), and so on. This was a great example. Dr. Boom, people got attached to him, so let’s bring him back and make him the leader of the science and the mechs and all the craziness that’s happening.

Above: Reno Jackson.
Chamberlin: I feel like Magnetic brings this very different flavor to the mechs. I’m a little biased, because I love Magnetic, but it’s such a cool mechanic. It gives you a bunch of ways to interact. You can use the Magnetic minions as regular minions. You can use them to buff the mechs you already have in play. The way the UI is set up, you get a bit of positional strategy out of how you’re placing your minions on the board. Magnetic opens up a lot of cool new things to do with mechs that adds on to what we had with GvG.
Donais: It makes you go back and look at other mechs. How good would they be if you tried to put Magnetic mechs on top of them? Harvest Golem doesn’t see a lot of play right now, but because he’s a mech that, when he dies, makes another mech, he’s especially good with Magnetic because you’re more likely to have a mech in play when your next turn starts. I think we’ll go back and figure stuff like that out. Magnetic is mainly in Warrior, Paladin, and Hunter.
GamesBeat: Paladin is a deck with a lot of buffs, like Blessing of Kings. With Magnetic, the buff can just be a minion. Is there any worry that this devalues traditional buff cards?
Donais: I think buff cards are getting played in the buff decks while the mech cards are getting played in the mech decks. Obviously the Magnetic is more valuable if you have a lot of other mechs in your decks. Some Paladin decks don’t run any mechs, so in that case the Magnetic minions don’t make any sense. But if you’re running a Paladin or a Warrior deck with a bunch of mechs, then you’re going to want to use the Magnetic ones. We like to make cards that work better in context, and this is a good example of that.

Above: An example of a Magnetic card.
GamesBeat: Why go with the Netherstorm theme on top of Dr. Boom and the mech flavor?
Chamberlin: It brings a good bit of variety, I think. Goblins vs. Gnomes was a bit more about this head-on goofy clash. Now Dr. Boom, originally themed from the Netherstorm in WoW — him going back there to set up this big crazy lab, it’s a fitting location for it. It also gives us a good change of scenery to go and revisit not only Dr. Boom, but also all the different labs. What does mad science look like on a class by class basis? What does Shaman extreme meteorology look like compared to the new brand of mech that Dr. Boom and Warrior are looking into? The biology projects that Druids are working on. Stuff like that. It’s a good call back to Dr. Boom’s roots, and it’s also a good change of scenery to go and open up all this crazy stuff he’s been working on as something every class can get into.
Donais: Dr. Boom also liked that there was a bunch of floating islands around in this part of the Netherstorm. Normally the only floating island is Dalaran, so this is a nice place to find a lot of floating islands. Just pick an empty one and build your lab there.
Chamberlin: True. People take the mad genius title much more seriously if you have a floating island to go with it.
GamesBeat: Is this the first Hearthstone expansion to take place in Outland, a Warcraft location that is the floating remains of the Orc’s homeworld of Draenor?
Donais: Yep, this is the first one anywhere near the Outland. It’s a change of setting. We think it’s important for each expansion to have a little bit of a different backdrop, a different setting. That way we can use different monsters, creatures, minions. Netherstorm’s a great place to show off some new stuff.

Above: Electra Stormsurge.
GamesBeat: Is this a way of playing with people’s expectations? With the first Outland expansion,, most people would have thought it would be about the Dark Portal or The Black Temple. Instead it’s Dr. Boom in the Netherstorm and his crazy science lab.
Donais: Yeah, it’s him personified, right? A little bit crazy, a little bit fun. Those other ideas you listed sound cool too. Hopefully we’ll do those one day as well. But this is very Hearthstone. People who play a lot of Hearthstone are going to recognize Dr. Boom. They’ll recognize the mechs. They’ll enjoy the fun theme of the scientists doing crazy science, and each of them having a legendary spell that shows off how crazy they are.
GamesBeat: The legendary spells are interesting. When you designed those, did you take any lessons from designing legendary weapons or any of these other class legendaries that aren’t just minions?
Donais: Yeah, I think we learned from legendary weapons. We learned from legendary quests. We also learned a bunch from legendary minions. Even just epic spells, with the really big effects, we learned from those too. Myra’s Unstable Element, the first one we revealed, which is draw the rest of the deck — that’s not something we would do normally. It’s crazy. Most people wouldn’t know — what is that gonna do? Is that bad for me or good for me? What happens if I draw two of these, if it’s a common or a rare? It’s a perfect design for a legendary. You get one copy. People are going to have to really think about it. But they’re more inclined to think about it because it’s a legendary. It’s got all this cachet.

Above: Myra’s Unstable Element.
GamesBeat: We’ve seen a lot of minions with strong Battlecry effects. What makes a legendary spell stand out from just a legendary minion with a strong effect attached to it?
Donais: Well, you don’t get the body on the legendary spell. You just get the effect, so you have to make it even more significant, right? With minions, you can do a smaller effect because you put a big body on it. Electra Stormsurge is one of the legendary minions we’ve revealed so far. She’s a 3 mana 3/3, so she’s already got a bunch of stats. If you don’t get her Battlecry to work – if you have to play her on turn three just because you’re desperate – you can do that. But with legendary spells you really need to get the benefit from that effect. It’s a pretty big deal.
Myra’s Unstable Element is especially cool because you can prep it out with Rogue and make it 2 mana, so you still have maybe eight mana left to cast all the things the you can draw, and you’re going to draw lots of cards. I think it’s awesome for Rogues. You’re going to get some good use out of that.