Hearthstone's Most Exciting New Card, Zephrys The Great, Is Your Own A.I. Helper

Hearthstone's upcoming Saviors of Uldum expansion is introducing a lot of interesting new cards that are sure to shake up the meta-game. But during its final card reveal livestream, Blizzard introduced one of the coolest and (according to its engineers) most complicated cards yet: the Legendary Zephrys the Great.

Zephrys is a 2-Mana 3/2 Legendary minion that grants you a wish for "the perfect card." Under the hood, that means the game is examining all the public factors in your game, and offering you three options for cards that might help. If you happen to need to clear the board, he might offer you some area-of-effect spells. If your board is already solid, maybe he'll offer you a buff.

It's a simple concept, but it was apparently extremely hard to implement. Game Designer Chadd Nervig said on Twitter that "the amount of effort that went into bringing you this one individual card absolutely dwarfs all other cards." He also pointed out that Zephrys is even smart enough to hand you lethal damage to finish a match before you necessarily realize why it's offering a particular card.

In follow-up tweets, Nervig explained that Zephrys only looks at all the public info in a game--like how many cards are in your hand, minions on the board, and Mana crystals--but not private info like what you or your opponents' cards are. Also, for obvious game balance reasons, Zephrys won't ever offer you a way to replay him, like a bounce-back effect. It also comes with a limitation in that your deck can't have any duplicates. This is commonly known in Hearthstone as a "singleton" or "Reno" deck.

As a Legendary card, Zephrys will be difficult to pull from random packs and expensive to craft. But as a value-generator that's smarter than the average card, it's probably a smart pick to be among your first crafted cards for Uldum.

For more cards from Hearthstone's Saviors of Uldum expansion, including our own reveal of the powerful puzzle Mogu Cultist, check out our full gallery of all the cards coming in the expansion. Saviors of Uldum is now available, and you can get a free Legendary Quest card by logging in during the launch period.