Instability

Instability was the Wizard's mana-replacing resource during much of the development of Diablo III.

Instability was removed from the game in mid-2010, since the D3 Team could not get it functioning as they wanted. The Wizard's resource is now called Arcane Power, which functions very differently than mana or Instability were going to.

• See the Arcane Power article for more details.

Wizard's Resource Development

Wizards used mana when first introduced at Blizzcon 2008, and also in the Blizzcon 2009 demo. Shortly after that show, Blizzard announced that all classes except for the Witch Doctor would use something other than mana for their resource. The Barbarian's Fury was announced around that time, with the Wizard's resource described, but not yet named. The term "Instability" was not revealed until some months later.

Instability's Functions

Instability was meant to encourage a fast-paced, always attacking style of play. The main theory was for the resource to make the Wizard "more blasty, but more vulnerable." Jay Wilson first described it in October 2009. [1]

Jay Wilson: Well for the Wizard we want to enforce the fact that she’s a glass cannon. I don’t think it’s fun to ever run out of mana. I’m not really interested in an extended resource for her. For the WD we’re okay with mana, since he’s got some pretty good skills to recover mana that also double as attacks. And he’s not defenseless when he’s out of mana. He’s got pets and ways to attack with them that aren’t mana intensive. For him that makes mana fairly interesting.

For the wizard, when she’s out of mana she just dies. And that’s not fun. So if anything, we want to encourage how she plays. So she’s the kind of character that blasts first and asks questions later. Very vulnerable. So we want to implement a system that makes her more blasty, but even more vulnerable. We want to make that a choice for the player. "Do I want to make myself more vulnerable in exchange for being more blasty." And that’s a cool gameplay pull there.

Problems with Instability

The logic behind the change to Instability is that mana did not work as a limiting resource in Diablo 1 or Diablo 2. The play style of mage characters in the Diablo series is one of constant spell-casting. Therefore a resource that tries to limit spell casting is flawed, since players will always work to circumvent it, or else be crippled by it. As Jay Wilson said, a Wizard that can't cast spells is no fun.

This "more blasty and more vulnerable" paradigm was apparently reworked sometime during 2010, judging from an update in August of that year. A fan summarized what was known about Instability, and Diablo 3 community manager Bashiok said it was all changed. [2]

Instability on the wizard. All we know is what Jay Wilson said. She gets more “Blasty” as she gets more “vulnerable.” They have said it will make more sense then mana did once we learn about it which is cool

Bashiok: This is no longer the case. More at BlizzCon.

Instability Removed

Jay Wilson revealed that Instability was gone in an interview from Gamescom, in August 2010.[3]

Jay Wilson: For the Wizard, we could not get a version of Instability that we liked. The last version involved buff and debuff that would hit the wizard whenever she went unstable. And it was a pretty severe buff. It doubled all her damage taken while increasing her critical hit damage. And it just didn’t affect how people played. They didn’t notice it, and when they did it didn’t change what they were doing. That’s not the point of a resource. It needs to be managed to change the way that you play.

So now it’s called Arcane Power and it’s not dissimilar to mana, in a lot of ways. It regenerates very quickly, but it doesn’t grow over time. It’s a flat amount. A lot of passive skills that enhance it.

Instability Design Theory

As Jay said when announcing the change to Arcane Power, the point of Instability was to create a resource that had a clear effect on the Wizard's gameplay. Instability was intended to make the Wizard cast spells more effectively while increasing the danger to herself.

Clearly, the D3 Team were not happy with how that worked, and from what Jay said about the decision, they tried all of the stuff fans discussed[4] for buffs and debuffs. Common suggestions for buffs (blasty) included faster casting rate, higher spell damage, larger spell radius, and longer spell duration. Common suggestions for debuffs (vulnerable) include reduced movement speed, reduced spell casting rate, lowered hit points, lowered resistances, and lowered defense.

Apparently, none of those things changed the basic gameplay enough to make it work as a resource. Though details of Arcane Power have not yet been revealed, it doesn't sound greatly dissimilar from Instabilty. With both resource systems, the Wizard is a constantly-attacking spell caster. The gun is always loaded; only the size of the available bullets will vary.

Why Not Mana?

During the game's development, some fans continued to question the change to Instability and then Arcane Power, there was much discussion about[5] why mana had been abandoned as a resource. Bashiok replied to a typical post on this issue in March 2010. [6]

We still don’t feel mana fits the feel of the wizard class, and making the wizard use mana to match some definition a magic wielder from some other game from some other decade would be shoehorning mechanics for the sake of nostalgia.

We’re using the instability system for the wizard because it makes sense to the style of the class; thematically as well as mechanically. If mana filled those requirements we’d use it, but it doesn’t.

I don’t want to sound like we’re being dismissive. As everyone should be aware we work iteratively and the main reason why we haven’t revealed a lot about instability is that it still hasn’t been proven. If it turns out it doesn’t work we’ll try something else. It may be that mana just works the best and we end up going with that, but right now we’re trying something.

Health Orb Benefits?

Since the announcement of Instability, players have been wondering if health globes would benefit it, or Arcane Power. Health globes added to the Wizard's mana (and they boosted the Witch Doctor's as well) when used in the Blizzcon 2009 demo, but did nothing for the Barbarian's Fury. Jay Wilson addressed this issue in an October 2009 interview. [7]

Diii.net: Do you envision the health globes will boost [instability] in the way that the Wizard and Witch Doctor gained mana from them at Blizzcon?

Jay Wilson: Um, maybe? *sounding intrigued* Usually in the third or fourth skill revision on classes we look at that kind of thing. For the Witch Doctor we figured that a lot of the mana things we had on the Wizard would work better on the Witch Doctor. We were having trouble maintaining enough mana while play testing the Witch Doctor. Especially if players didn’t take a specific mana recovery skill. So we focused on spreading that out across a lot more of the class so he can pull mana back more easily. When we get to other classes I’m sure we’ll look for more of that.

But the key is that we don’t necessarily want to... we don’t want to cannibalize an existing gameplay mechanic. So when you take health globes that are already important, and you make them even more important, then that doesn’t really create gameplay. For the WD, the health globes weren’t that important a lot of times, since he very rarely took damage with his pets, so for him by enhancing his desire for health globes, we’re really putting gameplay where it wasn’t. So whatever we’re designing a class that’s what we look at.

References

• Monk Mana Resource System Progressing
• Jay Wilson interview
• Instability all changed, more details at BlizzCon 2010.
• Instability out, Arcane Power in, Jay Wilson from Gamescom, August 2010.