Blizzard continues balancing a new set right up until release.

The process of releasing a new set of Hearthstone cards is mysterious to many. Some first hear about it the second it goes live in the store and others follow along day after day as the release date draws nearer. Regardless of which camp you fall into, you may not entirely be familiar with how sets are actually developed. Does Blizzard actually have today's meta in mind when it is creating cards for the next expansion?

Depending on how long you've been around the Hearthstone community, you may already know that cards are created by two teams of game designers: the initial design team and the final design team. One comes up with ideas, concepts, and themes and the other takes care of the actual balance of things.

After each release, there's always a group of players that wonders if Blizzard is actually in tune with the meta when they're creating cards and Game Designer Max McCall has responded to one such player who complains via the Hearthstone forums.


Most of the cards in a set stop changing about two months before it releases, but we can and do change cards up until a week or two before release. The design process is complicated because the folks who work mostly on card sets* are working on multiple sets at once. It’s complicated further by the fact that each set ends up having two teams work on it: an initial design team and a final design team.

The initial design team lays out the vision for the set. They determine the setting, the theme, the mechanics, and sketch out ideas for new deck types that support the set vision. They handle the names, art, and flavor text for each card. For most of the time that this initial team is working on the set, the goal isn’t really ‘make the set fun’ so much as it is ‘figure out what can be made to be fun.’ The goal is to figure out what the new set will be about and what new decks people will build with the cards.

Then, the initial design team hands the set over to the final design team. The final design team takes the set and makes it as fun as possible. A substantial amount of the work that the final design team does is to make sure the set’s complexity is appropriate. Weird and scary cards that reinforce the set’s theme are protected, but cards that are needlessly complicated are saved for another day. The final design team also ensures that the set has an appropriate power level. They play a ton of games to ensure that the new deck types are fun; part of that is making sure that they are strong enough to compete with current decks but not so strong as to obsolete them.

The final design team does this for three to four months per set. They ‘finish’ work on a set about two months before it is released, and move on to the next set. But, just because they’re working on, say, Mean Streets doesn’t mean cards in Karazhan are locked. The rest of the team (production, engineering, art, sound, QA, etc) spends that time working on visual effects and bug fixing, and we tweak cards in this period if we want to react to a new deck in live or discover a new interaction with the even-more-future set that we’ve moved on to.

*There are a ton of designers who don’t work directly on card sets, either. The folks who work on Tavern Brawls, Fireside Gatherings, adventure missions, new player experiences, new and reworked systems (e.g. set rotation, Arena changes, etc) and the UI elements that hold everything together are always working on newer and cooler stuff.