Hearthstone update 20.4 patch notes bring Mutanus and Guff to Battlegrounds

This coming Thursday will introduce some big changes to Hearthstone with the introduction of the Wailing Caverns mini-set. However, that won't be all that players should expect to see. Hearthstone Battlegrounds is getting some major additions, while Standard and Wild will see some nerfs to a few Paladin and Shaman cards.

Hearthstone Battlegrounds has had some fun with Quilboar over the past few weeks. Quilboars will now be subject to the same rotation as every other tribe starting on Thursday. On top of that, Maiev Shadowsong is stepping away from the hero rotation for the time being and will be replaced by two new entrants: The lovable oaf, Guff Runetotem, and the fearsome new Murloc fighter, Mutanus the Devourer. Guff's Hero Power is the 1-Cost Natural Balance, which gives a friendly minion of each Tavern Tier +2/+1. Mutanus' Hero Power looks significantly more broken, as Devour will sell a minion and pour its stats into another friendly minion. Did I mention Devour costs nothing and gives the player an extra Gold?

In terms of minions, the Siegebreaker is going away. He'll be replaced by the new Battlegrounds-exclusive Demon, Hexruin Marauder. He'll gain +3/+3 at the end of every turn, but only if you have six or fewer minions at the end of your turn.

Going back to Standard play, three cards are getting some adjustments and it sounds like bad news for Paladin players. Here are the changes coming this Thursday:

First Day of School (Paladin): Now adds two random 1-Cost minions to your hand. (Down from three random 1-Cost minions)
Hand of A'dal (Paladin): Now gives a minion +2/+1. (Down from +2/+2)
Unbound Elemental (Shaman): "Whenever" changed to "After."

The Arena season will change and feature the Core set, along with the following sets:

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

Are you more of a solo player? Boy, is June the month for you! Three different batches of single-player content are coming this month. The Book of Mercenaries: Xyrella will be playable with Thursday's patch. The Book of Mercenaries: Guff will be available on Tuesday, June 15. A week later, the Book of Heroes: Malfurion will playable. Completing Xyrella's story will reward a Priest pack, while finishing Guff and Malfurion's books will reward one Druid pack each.

Of course, this update features a slew of bug fixes. Here they are, according to the Hearthstone website:

Updated Friends List messaging to indicate whether friends in Play Mode are playing Ranked or Casual, and which format they are playing.
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.
(NEW) Fixed a bug that prevented the “Borrow Decks” feature from working.
Fixed a bug where cost-reduction effects on Dormant minions would persist after the Dormant minion was played and awakened.
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.
Fixed a bug that caused Sparkjoy Cheat to use both Scabbs Cutterbutter discounts if it put a Secret into play with its effect.
Fixed a bug where Guidance’s Spirit Path option was not being counted as an Overload card when selected.
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.
Fixed a bug where Crabrider was not recognized as a Battlecry minion by cards like Field Contact.
Updated the wording of Shield Slam so that it accurately represents the way that the card interacts with Spell Damage bonuses.
Added language clarifying that both Classic and non-Classic versions of a card are removed from your collection when either version is disenchanted.
Fixed a bug where Elite Tauren Chieftan would sometimes generate non-Classic versions of cards when played in Classic.
“Quilboars” has been corrected to “Quilboar” as the proper plural form of Quilboar when displaying Battlegrounds minion types.
Fixed a bug where Reckless Apprentice’s effect would cause some minion-only Hero Powers to hit the enemy hero.
Fixed a bug that would result in duplicate treasures being offered in Duels.
Prevented cards of the same name from different sets being offered in the same Arena run.
Updated the Player Profile to display total wins for each game mode.
Fixed a bug where progress related to progression tracks, such as the “Tavern Regular” achievement, would not properly update.
Fixed a bug where reward pop-ups would sometimes not properly appear when the reward was earned.
Fixed a bug that prevented players from switching accounts on iOS devices.
Updated the New Player Experience to remove certain restrictions and to better indicate locked heroes, modes, and other features.
Updated MMR calculation for returning players to better account for their time away from the game.
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.
Fixed a bug that would make some Diamond cards not appear in your collection if owned.
Fixed a bug that would sometimes cause cards in hand to arbitrarily change positions.
Fixed a bug where the wrong description would sometimes appear for items in the in-game shop.

Hearthstone's 20.4 patch will be deployed on Thursday, June 3. That'll be the same day that the Wailing Caverns mini-set will be available for purchase. Brush up on our guide from earlier today to see all 35 cards.