'The intention isn't to make Arena like Tavern Brawl'—Hearthstone's Iksar on recent changes to drafting

Hearthstone's once-neglected Arena mode has been getting a fair bit of love lately. A year ago, Blizzard shifted the pool of draftable cards from Wild to Standard, then experimented with the ill-received synergy picks system. Most recently, patch 10.4 overhauled the draft system, now making it so players are always offered three cards of a similar power level. More importantly, when the new system was causing high-powered cards to show up too often, Blizzard stepped in quickly with a fix.

In other words, Arena feels like a healthier, better tended place these days. Last week, we chatted with senior game designer Dean "Iksar" Ayala, who said that though Blizzard dedicates substantially more time and resources to working on new card sets—there are 10 people on card design whereas Arena is handled by the systems team, which comprises just two people—many folk across Team 5 are passionate about making Arena the best it can be.

"Arena has really been a grounds in the last year where we're trying a bunch of different stuff," Ayala said. "The intention there isn't to make Arena like Tavern Brawl, where we're just changing things and doing wacky stuff. But doing events like the dual-class Arena for a short period of time is pretty cool. I think we'll continue to do stuff like that, but really we're still experimenting with Arena to get it into the best place it can be, so that then we can maybe not touch it for a while."

Not all of those experiments have been well-received though. The synergy picks system, where players were always offered two "build-around" cards at the start of a draft (in practice this meant a lot of Book Wyrms and Murlocs) was unpopular with pretty much all of the community. "Even with that, there was something there," Ayala said. "The implementation just wasn't right."

That's part of why the synergy pick system stuck around for so long, while the 10.4 draft overhaul was fixed almost immediately when it was offering too many high-powered Legendaries and board clears.

"Sometimes we're not sure there is a huge problem, or we actually want to experiment a little more," Ayala said. "We wanted to give the synergy picks a little bit more time before we made a snap judgement call."

With the Legendaries, on the other hand, it was clear there was a problem. "Not only does this skew the experience of Arena, when everyone has these really powerful late-game cards, but it also makes the moments where you do get a Legendary not feel so special anymore," Ayala said. 

"So that was a case where we knew there was an issue and were ready to make a decision on it. And then also it was a technically easy thing to do. The Arena draft format, in terms of how the cards are drafted and their probability of showing up, is just a server-side change where we change a number and click a button."

With the fix through, the 10.4 draft system overhaul has been fairly popular. (Though prominent Arena streamers Hafu and Kripp are split on the issue, so there is perhaps still some work to be done.) The new system offers cards "of a similar power level" instead of offering cards of the same rarity. Hearthstone cards can have a huge power level variance across the same rarity, so the new system puts more of the onus on players to pick the card that best fits their deck, not just the most powerful of the three offered. 

Ayala says that card power levels are determined by "pure data, there's no opinions," but we still see some interesting picks come up. A popular Reddit thread showed Prophet Velen being offered next to Nat Pagle and Nat, the Darkfisher.

"It's funny cause it seems like Velen is the pick, but he's kinda just a War Golem in Arena," Ayala said. "There's also lots of other weird stuff that you can read into. Like the person who picks Velen, maybe that person—Velen is a really flashy card, so it tends to get picked by the person who wants to do the flashy thing instead of the person who wants to do the 'I win the game thing.' So the kind of decks he ends up in, and the player types he ends up with—data is kinda hard to read. But in general, Velen and Nat Pagle are actually quite close in terms of power, at least in Arena." 

The other big change Arena saw lately was the addition of some Arena-only cards that were chosen via a community vote at BlizzCon last year—something Ayala says the team could revisit in the future.

"I don't know what happened to the ones that didn't get picked at BlizzCon," Ayala said, "but in terms of giving more stuff for Arena, I think doing Arena-only cards is a way to do that. And there's wild cards—I think it would be cool to find a way to use more of the card pool."

"There's a lot of interesting problems with that, so we'll have to figure it out."