'Iterate fast' and other design lessons learned from Hearthstone

Hearthstone lead designer Eric Dodds took the stage at GDC 2014 today to shed some light on the game’s creation and share some design lessons learned by a small team building a digital card game within Blizzard. To hear Dodds tell it, the Hearthstone team’s freedom to quickly iterate on prototypes proved immensely valuable. Of course, that’s hardly a novel tip. “It’s not rocket science to iterate fast,” said Dodds. “On Hearthstone we had tons and tons of bad ideas that we needed to try, and then not do.” Design time was also important — Dodds and fellow designer Ben Brode spent an unexpectedly long period of time planning out the game’s design before they were able to start laying down code. “I wish I could say it was planned, but a lot of our engineers were moved to another project, so we got a lot of unintended design time,” joked Dodds. In retrospect, Dodds points out that if the design team had had access to engineers early in the process, the design team would have offered guidance that was unfinished and half-baked. Devoting more time to pure design — done mostly with paper and Flash prototypes — up front lowered the chances that the Hearthstone team would have to make potentially expensive late-game changes. Dodds also points out that having two designers making paper prototypes is far, far cheaper than funding a full design team to scope and build prototypes in-engine. From paper, Dodds and Brode moved on to building Hearthstone prototypes in Flash. They were ugly and crude, but working out the Flash prototype allowed the team to quickly swap elements in and out to experiment with ideas for a purely digital CCG without having to worry about “junking up” the code of the final game.

Tricks to keep things simple

Dodds explained that Hearthstone was designed to be simple — “to make what’s cool about collectible card games and make it accessible to more people.” That spurred Dodds and his team to start considering the basic appeal of collectible card games — the core systems that make them satisfying to play. Of course, Dodds took pains to point out that Blizzard designers try to avoid compromising the depth and complexity of a game when trying to simplify and streamline it. Dodds claims that axing complicated CCG mechanics like unique minion abilities, card tapping, and resource variability inadvertently created a game that was less exhausting for people to play. When the design team realized how much more pleasant it was to play the game this way, they decided to ship the game without imbuing cards with any additional usable abilities or powers — you simply play your cards and take your licks. But it's possible to take streamlining too far. Dodds also revealed that the Hearthstone team were tired of “summoning sickness”, the traditional CCG mechanic, but found that removing it actually made the game much less satisfying to play. “We were trying to simplify something, but we lost so much depth,” said Dodds. “We just decided to undo it and do things the old-fashioned way.” Dodds reminded the audience that developers, either at Blizzard or elsewhere, should never expect to find a satisfying stopping point. Creators never want to stop adding things, says Dodds, and at some point you need to be okay with letting a project ship without your favorite pet feature. Hero powers were added to Hearthstone in order to compensate for the design team’s efforts to streamline the gameplay — removing powers and abilities from individual minion cards made the game a little too simple. By adding a single power to each hero that never changes, Dodds claims that the Hearthstone designers found a way to empower players with a power that never changes and is always available once a term.

Dodds claims the depth of Hearthstone is found in the ways the cards interact, rather than the cards themselves. Hero powers can trash minions, for example, while different types of minions can bolster each other and create opportunities for players to build complex decks that are interesting to play. “Really, we just listened to George Fan,” said Dodds. Fan is the creator of Plants vs. Zombies, and Dodds cites Fan’s GDC 2012 talk about his design process as a key influence in the way Blizzard developed Hearthstone to be easily accessible to a broad audience. To that end, the team tried to embrace the strengths of building a CCG in a digital realm. Dodds talked a bit about the “Secrets” system in Hearthstone, which supplants the traditional play-counter-play system of physical card games. Instead, Hearthstone has Secrets, cards that can be played facedown that do something when a specific set of requirements are met. Digital cards like Nozdormu, a dragon minion that changes the rules of the game by shortening the turn timer to 15 seconds, or Thoughtsteal, a spell that lets players copy 2 cards from their opponent’s hand into their own, can only exist in a digital CCG like Hearthstone. The Thoughtsteal card, in particular, made players much happier by permitting them to copy cards rather than outright steal them. But make sure you “don’t change too much,” said Dodds, who suggested that developers should try and adhere to established conventions of the genre they’re creating in whenever possible. “Anything you don’t have to explain to your player is a godsend.” Dodds claims that by eliminating any vestige of overt narrative from Hearthstone, Blizzard sought to provide players an arena for them to tell their own stories. Dodds claims that the Hearthstone team actually designed cards specifically to inspire storytelling — he used the Millhouse Manastorm card, a cheap, powerful minion that allows your opponent to cast spells at no cost for one turn, as an example. Manastorm's special ability encourages wild, chaotic shifts in play, and that tends to create opportunities for cool stories to hapen. Dodds devoted a significant amount of time to discussing how designers can and should be sensitive to player feelings, moment to moment. “It’s very important to be paying attention to the emotional state of your player,” said Dodds. He suggests that designers take time to think about how the player might be feeling while they’re interacting with whatever gewgaw or UI element the designer is working on -- even something as simple as the animation that loops while a player is looking for an opponent. In the end, fun proved paramount. “It’s fun to play those, but it’s no fun to have those played against you,” said Dodds, in reference to archetypal counter-spelling or resource-burning CCG decks, which aren’t feasible in Hearthstone. “The emotional negativity was so strong that we felt like we couldn’t have those in our game, so we cut them.”