- See also: Advanced rulebook#Changes to game rules
- This update addresses the unintuitive resolution of "whenever" and "after" effects. Now, in order for a card's trigger to activate during a sequence of triggers, the card needs to be present and valid before the sequence of triggers begins. In other words, all triggers in a trigger sequence are validated before any can activate. Since all triggers are initially validated, new triggers that appear during a trigger sequence are invalid and no longer activate.
- Example: Player 1 has a Mad Scientist on the board, and a Mirror Entity in their deck. Player 2 plays Stampeding Kodo. Stampeding Kodo kills Mad Scientist. Mad Scientist pulls Mirror Entity into play. Mirror Entity does NOT trigger, because it did not exist when Stampeding Kodo was played.
- Example: Player 1 has a Piloted Sky Golem and a Wisp on the board (played in that order). Player 1 plays Deathwing. The Piloted Sky Golem spawns a Cult Master from its Deathrattle. The Cult Master does not trigger off the Wisp's death, because it wasn’t present to see the Wisp destroyed.
- Example: Player 1 has Starving Buzzard and Rotface on the board. Player 1 also has a Flame Leviathan on top of their deck. Player 1 plays Savannah Highmane. Starving Buzzard triggers off of Savannah Highmane, causing Player 1 to draw Flame Leviathan. Flame Leviathan triggers, dealing 2 damage to all characters. Rotface triggers off the damage and summons Spiritsinger Umbra. Spiritsinger Umbra does not trigger off the Savannah Highmane, because she was not present when Savannah Highmane was played.
- Counterspell beats whenever and after triggers.
- Summon and Play triggers are now evaluated using their in-hand stats before they are affected by board modifiers and their Battlecry.
- Minions that enter the battlefield without being played from hand will have any (Whenever or After) summon triggers evaluated before board modifiers are applied.
- Choose One minions that Transform now consider their transformation effects before entering play.
- Example: Playing Shellshifter and selecting the 5/3 option will count as a 5-attack minion and advance Jungle Giants.
- If a card is copied, the copy will now retain enchantments, unless copying to a different zone in a "backward" direction.
- Example: If a card is copied from deck to a deck, the copy retains enchantments. (eg. Archbishop Benedictus)
- Example: If a card is copied from a hand to a hand, the copy retains enchantments. (eg. Mind Vision)
- Example: If a card is copied from play to play, the copy retains enchantments. (eg. Molten Reflection)
- Example: If a card is copied from a deck to a hand, the copy retains enchantments. (eg. Thoughtsteal)
- Example: If a card is copied from a deck to play, the copy retains enchantments. (eg. Mindgames)
- Example: If a card is copied from hand to play, the copy retains enchantments. (eg. Kobold Illusionist)
- Example: If a card is copied from a hand to a deck, the copy does not retain enchantments. (eg. Dead Man's Hand)
- Example: If a card is copied from play to a deck, the copy does not retain enchantments. (eg. Baleful Banker)
- Example: If a card is copied from play to a hand, the copy does not retain enchantments. (eg. Feral Gibberer)
- Cards that transform will no longer keep any enchantments when they transform.
- Different damage redirection effects can chain with each other, but each one will only occur once. Re-directed damage is applied before modifiers (e.g. Cursed Blade) and will only damage the final target once.
- For some great examples of damage redirection, see Snapjaw Shellfighter#Notes.
- However, Shirvallah's Vengeance is still able to chain with itself.
- Example: If both the player and the opponent have one on their field, 5 damage will keep being dealt from player to player until one player is defeated.
- Discover cards can no longer Discover themselves as a random effect; however, Discover cards can still Discover copies of themselves from places that exist in the game, such as from the hand, deck, graveyard, etc.
- Example: Nature Studies is not able to Discover another Nature Studies.
- Example: Primordial Glyph is not able to Discover another Primordial Glyph.
- Example: Frightened Flunky is not able to Discover another Frightened Flunky.
- Example: Emerald Explorer is not able to Discover another Emerald Explorer.
- Example: Shadow Visions is still able to Discover a copy of Shadow Visions in the deck.
- Example: Madame Lazul is still able to Discover a copy of Madame Lazul from the opponent's hand.
- Example: Stitched Tracker is still able to Discover a copy of Stitched Tracker in the deck.
- Example: Body Wrapper is still able to Discover a copy of Body Wrapper from the graveyard.
- Cards that 'generate a random card' can no longer generate themselves.
- Example: Evocation is not able to generate another Evocation.
- Example: Sky Raider is not able to generate another Sky Raider.
- Example: Jar Dealer is not able to generate another Jar Dealer.
- Example: Underbelly Angler is not able to generate another Underbelly Angler.
- Example: Dune Sculptor is not able to generate another Dune Sculptor.
- Example: Jandice Barov is not able to summon another Jandice Barov.
- Example: Lightforged Crusader is not able to generate another Lightforged Crusader.
- Example: Skeletal Dragon is not able to generate another Skeletal Dragon.
- Example: Psychic Conjurer can still copy a Psychic Conjurer from the opponent's deck.
- Example: Shifting Shade can still copy a Shifting Shade from the opponent's deck.
Dev comment: Overall, this change is aimed at helping games feel a bit more varied. While generating the same card can be an exciting individual moment, these types of experiences tend to have diminishing returns after a while. These adjustments should make for healthier games against classes with a ton of resource generation.
- Main article: Advanced rulebook
This wiki provides an advanced rulebook providing extensive information on the game mechanics of Hearthstone.