Hearthstone's new Horde-themed expansion is all about leveling up

10 mercenaries will be the stars of this year's Hearthstone sets.

World of Warcraft fans take their allegiances to the Horde or the Alliance so seriously that they've been known to accuse Blizzard developers of showing favoritism to one of the two perpetually warring factions. So when Hearthstone's next expansion Forged in the Barrens was announced at BlizzConline, the developers were quick to promise that the Alliance would also get a set focused on them.

"The Barrens just seemed like a great place to start," said associate game designer Cora Georgiou. "It's not that we have any bias towards the Horde or the Alliance. The Barrens is such a really great place to level early on as a new character in the Horde. It was really important to us that this year really start at the basics."

Leveling up is a major theme for the Year of the Gryphon, which will bring some of the biggest shakeups to Hearthstone since the game's launch in 2014. All of this year's releases will follow the story of 10 mercenaries, five Horde and five Alliance, who will each be represented as legendary minion cards. The first of those, the troll shaman Bru'kan, was revealed during the Hearthstone BlizzConline presentation and card art indicates that one of the others will be an undead warlock.

Those stories will be revealed in part through Hearthstone's Book of Heroes single-player game mode but also in the card art. Forged in the Barrens introduces a new mechanic called Ranked Spells that has three different progressively more powerful effects based on the amount of mana you have when you play them.

The idea was in part inspired by the Spellstones of the 2017 expansion Kobolds & Catacombs — which were powered up if you met certain criteria like playing a weapon — and the Omega cards from the 2018 expansion The Boomsday Project, which had powerful bonus effects if they were played when you had 10 permanent mana crystals.

"We thought, generally with the way the gameplay goes, cards are going to be weaker in the early turns and stronger in the late game," Georgiou said. "Wouldn't it be cool if a card could be both at the same time? That was kind of the mentality with it. They're cards that improve as the game goes on and become more useful as you need them."

The art for every Ranked Spell features one of the 10 mercenaries and are meant to indicate the characters leveling up.

"In Chain Lighting you see Bru'kan and you see Bru'kan growing in power as the spell ranks up," Georgiou explained. "It was really important to us that all three versions of the same spell are very cohesive. They're all very coherent. You can follow the progression of the story over the course of the spell ranking up. You see Bru'kan getting more powerful as chain lighting itself gets more powerful."

The other new mechanic introduced in Forged in the Barrens is Frenzy, which gives minion cards a one-time effect the first time they survive damage.

"it's really important to us that our mechanics feel thematically relevant and thematically linked," Georgiou said. "In this case, frenzy really tells the story of the resilience of the Horde. They're getting knocked down, but they're always getting back up again and they're even more ferocious than before because now they're injured and now they're mad. We got a taste of one-time triggers with Spellburst in Scholomance and we really liked them. They allow us to do some really cool effects that maybe wouldn't be possible if it was a repeatable effect."

The same progressing art style on Ranked Spells is found in Hearthstone Mercenaries, an entirely new play mode introduced during the BlizzConline presentation. While the developers are still keeping many of the details on how Mercenaries works under wraps, such as what form battles will take or how you'll acquire heroes, it's been described as more of a tactical RPG experience with roguelike elements.

"You'll be collecting some of those famous World of Warcraft characters and they'll have different abilities and go through combat phases," said senior game designer Alec Dawson. "The big thing that separates it from normal Hearthstone is there is a big focus on progression — collecting those heroes, leveling them up with equipment, and giving them some new abilities and then the roguelike stuff. Each run is going to be pretty different."

"Hearthstone has changed a lot over time, but at its heart Hearthstone is still the same."

Each character has three modes, each with its own art, and they grow in power as they level up. While the mechanics will be very different, playing Hearthstone Mercenaries will still earn players XP for the game's Rewards Track system.

"It's very important to us that every aspect of Hearthstone that you play sync with our Rewards track and earn you progress," Georgiou said. "We're just consistently trying to improve upon ourselves and make our game better. We think that one way that we can really do that and to give our players the best experience is to give them different ways to play Hearthstone."

The release of Forged in the Barrens will coincide with the first rotation of Hearthstone's core set, something that Dawson said has been under consideration for years as the team and the game has grown. Going forward, the core set will rotate annually, with about 30% of the cards changing based on the archetypes they want to push and plans for the next year's expansions. The refreshes also provide the developers the chance to bring back fan favorite cards. Players who want to use the old core cards can check out the new Classic format, which will launch the same day as the rotation.

"Hearthstone has changed a lot over time, but at its heart Hearthstone is still the same," Georgiou said. "We owe a lot to the way Hearthstone was in 2014. We're excited for people to get to experience that again."

Much like its parent game did by releasing World of Warcraft: Classic while continuing to progress the story with Shadowlands, Hearthstone hopes to provide the mix of nostalgia and constant updates to satisfy its wide range of players as one of the best multiplayer games.

"I think right now the game is as healthy as it ever has been," Dawson said. "There's millions and millions of players playing Hearthstone every day. That says so much about what we're doing. We think we're giving a lot of great content out there. Our main mission is just to continue to be the best place for card games and create different modes within the card games as well. We think the core set and Forged in the Barrens is another great step in that direction."