When Hearthstone glitches out, you can see it. Cards fall into crevices of the board they should never go. Graphical effects linger perversely. Turn timers run on with no apparent end.
Usually, to break Hearthstone this way, you need to pull off some strange once-in-a-blue-moon interaction with obscure cards and janky animation mechanics that are ripe for exploitation.
But now, with the release of Hearthstone's latest Witchwood expansion, one of the most popular decks in the game is actually built to push Hearthstone's inner workings to their limits, and it revolves around a single card.
Since it re-casts all the effects of the Battlecry minions you've played in that game, you can essentially set up a Shudderwock that copies itself, returns those copies to your hand, damages the enemy hero, and heals your own, ad infinitum.
The only catch is that once you get sufficiently deep into a game, the card often triggers dozens, if not hundreds, of Battlecries, each with its own animation cycle that you don't really have the ability to skip.
As the first week of the expansion has proved, Shudderwock is a havoc-wreaking mess that can single-handedly win games while breaking the inner workings of Hearthstone as we know them.
On release day, the popular streamer Disguised Toast played a Shudderwock deck that conquered nearly every opponent it encountered, often destroying some of the game's mechanics in the process. At the beginning of this video, he ends up with 11 cards in his hand when the maximum is 10:
If you watch the rest of that video, you know pretty much exactly what to expect out of a Shudderwock deck: The Shaman will copy their Shudderwocks, suck away some of your health, and then play more Shudderwocks until you're dead. If you can't kill them once the Shudderwock engine gets up and running, it's likely you'll sit there for minutes at a time watching animations go off until you're dead. Not a very fun play experience.
So why didn't Blizzard stop this? Funnily enough, Kotaku actually discussed the Shudderwock earlier this month with Hearthstone Game Director Ben Brode (who, I assume coincidentally, said today that he is leaving Blizzard).
Even though it hadn't been released at the time, Brode predicted that it'd make waves in the metagame and the meta-metagame.
"I watched a guy play Shudderwock, summon an exact copy, and then there's another card called Grumble, who returns all of the minions to your hand, and now they cost one. And so that battlecry went off, and that second copy went back to his hand with a cost of one. And there's 20 other battlecries. So this thing went on for a minute - and then he plays the second Shudderwock." Brode shook his head, laughing.
Brode tried to put a stop to the madness, telling his colleagues: "Guys, whatever card you made that enables this, you just change it right now." No can do, they told him. All of those cards are going into The Witchwood.
Now that the Hearthstone metagame has shifted a bit since those initial launch dates, it's become clear that Shudderwock decks aren't necessarily the strongest - mostly because they take so long to get up and running.
Still, sitting through endless Battlecry animations seems to go against the concept of Hearthstone as a fun and interactive game, and so last weekend, Hearthstone Senior Game Designer Dean Ayala mentioned that the team was looking to "revisit the Shudderwock topic" on both a balance and technical level.
The card might not be overpowered, but we can hope that at the very least, Blizzard will do something about those animations.