The Invisible Bunnies That Power World of Warcraft

Illustration for article titled The Invisible Bunnies That Power World of Warcraft

Yesterday, I posted about a Fallout 4 mod that uses a complex, intertwining network of, er, kitties to make radios work. Turns out, game development is full of stories like that. World of Warcraft, for instance, is overrun with ghost bunnies.


WoW encounter designer Nathaniel Chapman explained it to me via Twitter.

“A lot of stuff behind the scenes that you wouldn’t expect to be a spell in WoW runs using the spell system,” he said. “Spells need casters, so we often have to rely on spawning in an invisible creature to be the one to actually ‘cast’ the spell. Other things that creatures are good at doing would be hard to implement any other way, so we use an invisible creature instead.”

He offered the example of the laser turret in this raid:

Video courtesy of FatbossTV.

The ‘point’ of this laser turret is actually an invisible creature that is following a player with [a] laser visual and beam attached,” Chapman said. “It’s periodically casting fire zone spells.”

Different games use different invisible creatures. For WoW, it’s mostly bunnies. Chapman pointed me to a list of bunnies in the game, noting that every bunny on the list that’s not categorized as a “critter” is an invisible bunny oompa-loompaing around in the background of WoW’s endless chocolate factory. The list, I should add, is 1,000 damn entries long. These bunnies have some incredible names, too. For instance, there’s the Projections And Plans Kill Credit Bunny. I’m also partial to Pony Gun Bunny.

Why is WoW a front for a morally questionable bunny labor operation? The short version is, programmers’ time is limited, and NPCs’ time is not. “Programmer time is extremely valuable, and most of the ‘stuff’ that can be done in a game can be done by NPCs,” said Chapman. “NPCs already have to support things like pathing, casting spells, using weapons, doing various actions to other NPCs, etc. So, while you could in theory have a programmer separately implement every ‘effect’ you wanted in the game with some minor benefit, if you already have a class of thing in a game that can solve your problem, it’s a better use of time to use the existing system.”


“NPCs check off every box in the ‘what I want’ column, except ‘not visible to the player,’” he said. “So you make an invisible creature.”

He noted, however, that this is all case-by-case, and some individual effects and functions are better left to programmers. Principal server software engineer Kurtis McCathern added that there aren’t as many invisible bunnies in WoW as there used to be. The WoW team’s tools have become more refined over time, so they don’t have to duct-tape rabbits to lasers as much anymore. “Sometimes,” McCathern said, “you don’t know designers need a kitchen until they’ve made ramen in a flower vase with an iron.”


Other designers pointed out that games they’ve worked on or played were also built on the haunted remains of pet cemeteries:


So there you go. If you think you’re alone in your favorite game—quietly taking in the view, breathing the gentle spring air, and shouting your secrets as loudly as you can—you’re probably not. Beware the bunnies, for they see all.

Kotaku senior reporter. Beats: Twitch, streaming, PC gaming. Writing a book about streamers tentatively titled "STREAMERS" to be published by Atria/Simon & Schuster in the future.



Anarchy Online... Guild Wars 1... LOTRO... Copycats.

MUDs were doing this for ages for exactly the reason Nathaniel said: sometimes we need the game to do something that a creature is supposed to be doing.

Enter the Supermob. The hardest-working NPC you’ve never met.

Basically any time the game needed something to happen that’s normally done by a mob, it’s the supermob doing it. So an object that zaps you if you pick it up? The supermob zapped you when you picked the object up. A room that speaks into your brain? That’s the supermob talking.

Ironically this was actually open to some abuse if you knew exactly how the system worked (and MUD engines were largely open-source affairs, so knowing how the system worked was not out of the realm of possibility). Basically it worked like this:
- Your buddy wants to pull off something sneaky but there’s a room or object script that’ll prevent it
- You set up the timing exactly right such that you yourself trigger a room or object script that puts you into a combat state (like the aforementioned object that zaps you when you pick it up) even if only for a moment. You spam some kind of stun skill while that script is happening.
- If you’re supremely lucky and made the proper sacrifices to the volcano god you will actually stun the supermob (remember, it’s still just a mob) for however long your stun lasts.. usually a couple seconds.
- Your buddy in exactly that window does his thing that the supermob is supposed to stop through a script. The supermob can’t stop him because its stunned.
- Boom. That script just doesn’t fire and your buddy’s done something sneaky.

Obviously games like WoW are a lot more sophisticated than that and have easy ways to prevent those kinds of shenanigans, but it was still fun at the time to do random crazy bullshit like that.