Heroes of the Storm

From the Bullpen: Balancing Imbalances

From the Bullpen: Balancing Imbalances

Last article, I talked about imbalances – the special strengths and critical weaknesses of Heroes that serve the game in some important ways. However, the differences between Heroes can lead to unfairness (or at the very least, a perception of unfairness) in the game – and that’s the rub: this asymmetry makes for a compelling game experience, and should, therefore, be maintained. Yet somehow, we must control the asymmetry in a way that leads us to a “balanced” game.

How do we identify balance problems, and how do we address them?


There are three main methods for identifying a balance problem in the game:

The primary means we have to identify problems is actually engaging with the game ourselves. First and foremost, this means playing, but it also includes watching others play (from new-user testing to high-level tournament play). Balance design, like design itself, is largely about “feel”, not coldly examining the statistics. When something feels or looks “wrong” – if an Ability or Hero just seems unavoidable, indestructible, or feels unfair in a way that seems like a step too far (given an understanding of the game), we might have a balance problem on our hands.

Second, we listen to a lot of feedback from the community at large. Feedback gives the development team clues on what to look at: if we hear about it, we’re off to investigate it ourselves by playing, watching, or looking into the statistics. As designers, we tend to have a good idea of what feels good and what doesn’t, but we often – very often – can’t cover all angles of the game without more eyes looking at it. That’s where the players come in.

Finally, we look at trends from game data – things like Hero and Talent pick rates, win rates, and the like, through different filters (player skill level, number of players in a party, which Battleground, etc). We keep an eye on statistics to point us in directions we should be looking for balance changes. Very high pick-rates for Heroes or Talents, for example, drive us to investigate what the cause is. Much like a scientific experiment, raw data can help validate or refute the hypotheses generated by our own experiences or by the community’s feedback.

If all three factors are throwing up red flags, it’s time to react. Recently, we cut the Resurgence of the Storm Talent from the game, largely because the warning bells were going off everywhere: we felt something was wrong when we were playing it, we noticed it dictating which Heroes were considered “good”, we got tons of negative feedback about it, and lastly, statistics showed a near-universal high pick-rate across many skill levels!


There are two main ways to execute on a balance change: through tuning or redesign.

Tuning is the much simpler, faster, and more easily validated method. It’s just about changing the numbers – damage, cooldown, range, duration, and so on. We call these numbers “balance hooks” or “knobs”, and they allow a balance designer to quickly and easily change the power of a Hero. The balance design team works hard adjusting and giving feedback on these tunable values in order to make things fair, while still retaining the power of Abilities and Traits that define a Hero’s power.

Tuning knobs are critical for future-proofing balance reaction. When designing something, a designer must be aware of these tunable elements in his or her design, build them into the design, and work with balance designers on which knobs are okay to tune and which are not. For example, we recently changed the Promote Talent because we felt like it provided too much power with very little effort. We had two options: decrease the health/damage bonus offered by Promote or decrease the buff’s duration. The design intent was to make a Minion feel super powerful, so decreasing the health/damage bonus was off the table. Decreasing the duration of Promote not only helped solve the feeling of unfairness, but made it feel more active to play with!

Redesign means a change in the way something works at a mechanical level. Oftentimes, simple number tuning is not enough to address a feeling of unfairness, possibly because tunable numbers are simply not there! For example, Tyrael’s “Cast Aside” Talent (which was cut last patch) was very binary in its function: it’s a knockback/interrupt, and it’s either on or off. It’s difficult to balance the power of that Talent because there’s nothing to adjust. It’s removed for now, but we’re looking into redesigns of a competitive Talent that can take its place while also allowing for balance tuning, should the need arise.

Too much redesign is potentially disruptive to both the development team and the players, so we need to be careful when we employ it. Furthermore, we understand that redesigning or removing an element about a Hero will sometimes necessitate creating something new to take its place. While we’re in Beta, we use the redesign method more liberally, setting up Heroes and Talents in ways that allow non-invasive changes later.

Heroes of the Storm is a living, dynamic game. We expect to continue balancing characters constantly as we release new Heroes and Battlegrounds, and we want to continue talking about why changes are made through posts like this one. Just keep an ear to the ground – and as always, constructive feedback about what you feel is awesome, and what you feel needs work, is welcome and appreciated.

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