Defenders! Welcome to another edition of QA’s bug blog: Ninety-Nine Problems But A Bug Ain’t One [working title]. We’ve got a great bug this month: A mysterious, truly awe-inspiring issue that seemed to affect players at random!
Fire in the Dungeon! Fire in the Deeper Well!
For seemingly no reason, players began to burst into flames. We’re not talking a little spark, either. I mean this was undeniably, spectacularly broken and unignorable. This happened so infrequently that for a long time we couldn’t reproduce it with any reliability.
Let me put it into perspective. You’re playing the game with friends, having a good time. You notice one of the sub-objectives is being swarmed. The exchange goes something like this:
“We need a hand by the East Gate Lock,” you say, pinging the map.
“I’m on my way,” they answer, rushing to your side. “Incoming Heroic Wave!”
As the horde falls at your feet, you celebrate your hard-earned victory. “Yeah! We rule. Towers for days. Orcs got no game.”
And while you’re taking a victorious swig of your brand soda of choice, you turn back towards your monitor and see…
…And so you say something to the effect of: “Sweet sassy molassy! щ(゜ロ゜щ) What’s happening?!”
Just as quickly as it appeared, it ceases. Not only was this bug very rare, occurring maybe one in every thirty games, but it was such a distraction that it completely captivated us, even though the fire visual effects only lasted two or three seconds at most. We gathered no new information as to what caused it or any steps to reliable see it again, so it slipped through our fingers for a while.
We had to extinguish this bug. We focused up, and after some time, we managed to get it to happen again. We found out it was due to a specific part of our Town Square map, specifically an animation, or what level designers call a “cinematic event,” that played as part of the background.
Bug Type: VFX
Time Spent On 100% Reproduction Rate: 4 months
Time Spent On Fix: 3 hours
After I saw the bug and began eliminating possible explanations, I remembered browsing through the internal build when I first started working here and going down each letter of the alphabet to find console commands. I found one for castleseige2 — yes, siege is misspelled in the actual command line — that made me catch on fire randomly, but I didn’t link the command to the bug since the fire didn’t happen right away. I had to do a lot of experimenting once I found the command, because using it once didn’t give any results. It only made me burst into flames maybe once in every dozen times, so I used another command to keybind the castleseige2 cinematic event. Spamming the bound key made the bug happen within seconds, which gave us a reliable way to see it and fix it.
What happened was this: There’s an animation of cannonballs striking the castle in the background of that map on the northeast side that helps visually communicate the siege. This animation has different parts to it, like say, a fire visual. The frequency of the animation sometimes meant that the fire visual would sort of “overflow” and wouldn’t know where to go. For whatever reason, it went to the last thing that was affected by something with a particle effect, like fire from a goblin’s bomb, for instance. The end result was that it transferred to enemies and sometimes even heroes.
This bug is easily my new personal favorite. Easily. (￣︶￣)
Let us know what you think in the comments. This bug is fixed, but we’re interested in hearing how you might use this awesome superpower of random self-combustion. Maybe to roast a few marshmallows during your victory celebration? Tell us below, and you could win a seat on the Defense Council. Until next time!