Hearthstone's AI targets the intermediate level player

The AI of Blizzard Entertainment's card-based game, Hearthstone: Heroes of Warcraft, was designed to pose a challenge to players without overwhelming them, former Blizzard Entertainment senior AI and gameplay engineer Brian Schwab said today at Game Developers Conference 2014.

Speaking about his work on the game during "AI Postmortem: Hearthstone," Schwab explained that Blizzard's work on Hearthstone was "quite the experiment." Blizzard wanted to build a game that featured intelligent AI — but remained accessible to players of any skill level.

"There's this stigma of most card games that they're inaccessible," Schwab said. " ... Blizzard wanted more of a level of AI that was obviously doing something intelligent, but it wasn't overwhelming you."

In other words, the goal was to create an AI on the level of an intermediate player. Schwab accomplished this by interviewing many players of different levels and watching them play.

"What I really started to learn is that advanced players of Hearthstone don't play the game," Schwab said. "They play the meta game."

The meta game, he continued, is when players keep track of the cards in their opponents deck. Intermediate players "don't play that at all."

"They go straight for value," Schwab said. "'I want to play cards that give me resources in the game.'"

To match the intermediate level, the game's AI was created to hold back cards very rarely. It also doesn't cheat or have omniscience over the player, Schwab said.

Hearthstone exited its beta run — time which Schwab described as "pivotal" in development — only last week and is available now on Battle.net. For more on Hearthstone, check out Overview below.