Hearthstone is getting new Battlegrounds heroes and minions, and more Standard nerfs

Hearthstone's latest mini-set The Wailing Caverns, all of the cards from which have now been revealed, goes live tomorrow as part of the 20.4 patch. And honestly, who isn't excited to own a card called Kresh, Lord of Turtling?

The mini-set isn't all that's being added in this big, beefy new update. The patch notes released today also reveals new heroes and a new minion coming to the Battlegrounds, and a handful of nerfs including another bonk of the bat for Paladin's First Day of School.

The First Day of School nerf actually undoes part of a change made a few weeks ago in the 20.2.2 patch, which changed the card from 0 to 1 cost and increased the random 1-cost minions it adds to your hand from 2 to 3. The 20.4 patch reverts that back to 2 minions, but leaves the card cost in place. Another Paladin card, Hand of A'dal, is also being cut, so that instead of granting at +2/+2 minion, it will give a +2/+1. 

"First Day of School and Hand of A’dal are strong performers played in all four main Paladin archetypes (Libram, Aggro, Secret, and Menagerie), and we are nerfing them in 20.4 to help other classes close the gap with Paladin," Blizzard explained. "Another note on First Day of School: While the last balance change for this card only resulted in a mild change in power, we will still be attempting changes like it in the future. Our current balance philosophy is to move forward with light changes when we can, as we did when we first repositioned First Day of School, and we’ve seen great results over the past year with this approach."

Unbound Elemental is also having its card text cleaned up: Instead of gaining +1/+1 whenever you play a card with Overload, you'll get +1/+1 after you play the card.

More excitingly, two new Battlegrounds heroes are on the way:

Mutanus the Devourer

• Devour [Costs 0]: Remove a friendly minion. Spit its stats onto another. Gain 1 Gold.

Guff Runetotem

• Natural Balance [Costs 1]: Give a friendly minion of each Tavern Tier +2/+1.

And so has a new minion:

Hexruin Marauder

• [Tier 4, Demon] 3 Attack, 5 Health. At the end of your turn, if you have 6 or fewer minions, gain +3/+3.

As often happens with these things, the patch will also see Maiev Shadowsong temporarily removed from the Battlegrounds hero pool.

The Arena will also be rotated following the patch, and will then include cards from:

• Wailing Caverns Mini-Set
• Forged in the Barrens
• Darkmoon Races Mini-Set
• Madness at the Darkmoon Faire
• Scholomance Academy
• Ashes of Outland
• Kobolds & Catacombs
• Goblins vs. Gnomes
• Core

94 previously-released card backs and 11 hero skins will also be made available for purchase when the patch goes live. Card backs will cost either 500 or 600 gold, while the hero skins will go for 1200 or 1800 gold. You can expect more card back and hero skins to return in future patches: Blizzard said that new ones will continue to appear in the shop, "but we will periodically update the Collection with more returning Card Backs and Hero Skins going forward."

Here's who's coming to the party:

• Magni Bronzebeard*
• Alleria Windrunner*
• Medivh*
• Khadgar*
• Sylvanas Windrunner*
• Lei Shen/Thunder King*
• Dame Hazelbark*
• Maiev Shadowsong
• Morgl
• Lunara
• Sir Annoy-O

(Hero skins with * will also include their associated card back.)

New chapters in the Book of Mercenaries solo adventure will also appear throughout June, beginning with Book of Mercenaries Xyrella, which will go live on June 3 with the launch of the patch. Book of Mercenaries Guff will follow on June 15, and Book of Heroes Malfurion will wrap things up on June 22. Defeating eight bosses in each will net you a Priest (Xyrella) and two Druid (Guff and Malfurion) card packs, each containing only cards from their respective classes from Standard.

And as usual, there are a slew of bug fixes and gameplay improvements—25, in fact. Count 'em:

• 1 - Updated Friends List messaging to indicate whether friends in Play Mode are playing Ranked or Casual, and which format they are playing.
• 2 - Fixed a bug where copying Imprisoned Celestial with Mirror Entity resulted in the copied Imprisoned Celestial being unable to activate its Spellburst effect after awakening.
• 3 - Fixed a bug where cost-reduction effects on Dormant minions would persist after the Dormant minion was played and awakened.
• 4 - Fixed a bug where effects that trigger after or whenever a spell is cast would not trigger if Oh My Yogg! converted the spell into a new spell with no valid targets.
• 5 - Fixed a bug that caused Sparkjoy Cheat to use both Scabbs Cutterbutter discounts if it put a Secret into play with its effect.
• 6 - Fixed a bug where Guidance’s Spirit Path option was not being counted as an Overload card when selected.
• 7 - Fixed a bug where Bogbeam and Ironbark’s cost reduction effects would not activate after casting Celestial Alignment and going back up to at least 7 Mana Crystals.
• 8 - Fixed a bug where Crabrider was not recognized as a Battlecry minion by cards like Field Contact.
• 9 - Updated the wording of Shield Slam so that it accurately represents the way that the card interacts with Spell Damage bonuses.
• 10 - Added language clarifying that both Classic and non-Classic versions of a card are removed from your collection when either version is disenchanted.
• 11 - Fixed a bug where Elite Tauren Chieftan would sometimes generate non-Classic versions of cards when played in Classic.
• 12 - “Quilboars” has been corrected to “Quilboar” as the proper plural form of Quilboar when displaying Battlegrounds minion types.
• 13 - Fixed a bug where Reckless Apprentice’s effect would cause some minion-only Hero Powers to hit the enemy hero.
• 14 - Fixed a bug that would result in duplicate treasures being offered in Duels.
• 15 - Prevented cards of the same name from different sets being offered in the same Arena run.
• 16 - Updated the Player Profile to display total wins for each game mode.
• 17 - Fixed a bug where progress related to progression tracks, such as the “Tavern Regular” achievement, would not properly update.
• 18 - Fixed a bug where reward pop-ups would sometimes not properly appear when the reward was earned.
• 19 - Fixed a bug that prevented players from switching accounts on iOS devices.
• 20 - Updated the New Player Experience to remove certain restrictions and to better indicate locked heroes, modes, and other features.
• 21 - Updated MMR calculation for returning players to better account for their time away from the game.
• 22 - Fixed a bug where effects that added copies of Diamond cards to a player’s hand or deck would add Golden versions instead of Diamond versions.
• 23 - Fixed a bug that would make some Diamond cards not appear in your collection if owned.
• 24 - Fixed a bug that would sometimes cause cards in hand to arbitrarily change positions.
• 25 - Fixed a bug where the wrong description would sometimes appear for items in the in-game shop.

The full Hearthstone 20.4 patch notes are up at blizzard.com. The update goes live on June 3.