October Hearthstone Game Mechanics Update
In Hearthstone's October Patch we're getting an update to a couple of game mechanics. The goal behind these changes is to make the game work more intuitively. Core gameplay is not being changed, only rare edge-cases.
Ultimately, triggers will now be validated before they activate, so new triggers introduced onto the board during a chain of events will no longer fire. Watch the video below or read the huge informative text by Josh Durica and Daxxarri if you want to get more in-depth into the changes.
Josh Durica on Evolve
A change in the future will ensure Evolve effects aren't going to activate any summon triggers.
Quote from Josh DuricaThis mechanic change actually does not affect the Apothecary/Thrall interaction because that’s due to a different issue involving evolve effects activating certain summon triggers. However, we ARE specifically changing Apothecary in the next patch, so that it will no longer trigger off evolve effects.
Additionally, while it won’t make the next patch, we’re planning to make sure evolve effects won’t activate any summon triggers in the future.
Hearthside Chat with Josh Durica: Game Mechanics Update
Join Hearthstone Gameplay Engineer Josh Durica as he gives you an overview of what to expect from the game mechanics changes coming in Hearthstone’s October 2017 update!
In-Depth Explanation of Changes
Quote from Josh Durica and DaxxarriHearthstone has a lot going on under the hood. The cause-and-effect relationships when cards are played are relatively straightforward and easy to predict, but because of the way certain events are timed, some very surprising things can happen in rare circumstances. We want cards to work the way that you guess they might—in other words, we want the game to work intuitively.
In the upcoming patch, we’re making some changes in pursuit of that goal. We want Hearthstone to continue to be strategically deep: a game of careful choices, calculated risks, and exciting events. So we want to be extra clear that this update isn’t a change in depth; instead it’s one step in an ongoing effort improve Hearthstone’s mechanics.
Hearthstone’s core gameplay won't change, but what will change are some rare edge-cases.
Please be aware: what follows is a detailed look at Hearthstone’s mechanics by Hearthstone Gameplay Engineer Josh Durica. If you want to delve into the nitty-gritty details regarding how this change will work, read on.
First, A Glossary
Event
Events are interactions that occur throughout gameplay that can cause triggers to activate when they happen.
Example Events:
- Whenever a Card is Played
- After a Card is Played
- Deathrattle (When this minion dies)
- Whenever a Minion Takes Damage
- At the End of Your Turn
Trigger
A trigger has two parts: an event (usually starts with “Whenever”, “After”, or “At”), and an effect. Sometimes triggers can also have a condition (usually noted with “if” or “while”, but sometimes noted by qualifiers like “your”).
Example triggers:
- Whenever you cast a spell, gain +1 Attack.
- After you cast a spell, deal 1 damage to ALL minions.
- At the end of your turn, give another random friendly minion +1 Health.
- If you control a Secret at the end of your turn, gain +2/+2.
Zone
In Hearthstone, there are three zones where triggers can happen, and they happen in order: First, any triggers in the Battlefield, then those that occur in a player’s Hand, and finally those that belong to cards in a player’s Deck.
Sequence
Whenever an action is taken, Hearthstone executes a sequence of steps to resolve what happens.
Here’s a simplified example sequence:
- ACTION: A card is played (this begins the sequence)
- EVENT: Whenever A Card is Played
o Whenever A Card is Playedtriggers
resolve
- Card ability activates
- EVENT: After a Card is Played event occurs
o After a Card is Playedtriggers
resolve
Here’s what that sequence would look like using actual cards, if you had a Questing Adventurer and a Flamewaker on the board, and then played Frostbolt:
- ACTION: Frostbolt is played (this begins the sequence)
- EVENT: Whenever a Card is Played triggers resolve
o Questing Adventurer gains +1/+1
- Frostbolt’s text resolves: Deal 3 damage and freeze
- EVENT: After a Card is Played triggers resolve
o Flamewaker shoots two missilesThis is a simple example, but a sequence can incorporate many events and triggers.
Keep in mind that dealing damage, destroying a minion, and other things can interrupt sequences with new sequences, like in this more detailed example:
- ACTION: Frostbolt is played (this begins the sequence)
- EVENT: Whenever a Card is Played triggers resolve
o Questing Adventurer gains +1/+1
- Frostbolt’s text resolves: Deal 3 damage and freeze
o NEW SEQUENCE: Damage dealtEVENT:
Whenever a Minion Takes Damage triggers
resolve
- EVENT: After a Card is Played triggers resolve
o Flamewaker shoots 1 missile
- NEW SEQUENCE: Damage dealt
- EVENT: Whenever a Card Takes Damage triggers resolve
o Flamewaker shoots another missile
- NEW SEQUENCE: Damage dealt
- EVENT: Whenever a Card Takes Damage triggers resolve
In Pursuit of the Goal
If you watched the video in our recent blog post, then you saw two different examples of cards triggering in counter-intuitive ways because they weren’t present when the sequence that activated them took place. That sets the stage for the primary goal we wanted to accomplish with these changes:
If you want to trigger off something, you need to be present and valid when that something first happens.
A more technical way to say this is: In order for a trigger to activate from a sequence, it needs to be present and valid at the time the sequence began.
This means any card featuring a trigger that appears in the middle of a sequencecan’t activate during that sequence. So, when you play a card (or when a card is destroyed, or an attack occurs, etc.) you only need to consider what is currently on the board instead of guessing what the board state might be in the middle of the sequence. The Mindgames + Wild Pyromancer interaction showcased in the video is an example of an interaction improved by this change.
The valid qualifier is more subtle, but equally important. Before any trigger can activate, it needs to be validated. Each trigger has its own specific validation step, which allows the trigger to filter when it should and shouldn’t activate. For example, the Whenever a Card is Played event occurs when any card of any type (Minion, Spell, Weapon, etc.) is played. However, we want a card like Flamewaker to only triggerwhen a friendly spell is cast, so the Flamewaker’s validation step checks the card type and controller of the card played. In other words, Flamewaker’s trigger is only valid if the card played was a spell cast by Flamewaker’s controller.
Before our changes, we would validate triggers whenever their related eventoccurred, even if that was in the middle of the sequence. After the mechanics update, all triggers are validated when the sequence begins, and then they are only allowed to activate if they were valid from the start.
For further insight, let’s look at a bug that will be addressed by the update:
Currently, if you have a Djinni of Zephyrs on the board and cast Entomb on an enemy minion, your Djinni of Zephyrs will trigger, sending itself back to your deck. Not great for you or the Djinni! Djinni of Zephyrs triggers off the After a Card is Played event, and his validation step should only pass if the card played was a spell cast on a different friendly minion. Entomb is a spell, but it was cast on an enemy minion, so why does Djinni trigger?
Remember: the After a Card is Played event occurs after the ability on the played card resolves. In this case, that card is Entomb, and its ability moves the enemy minion into your deck. When the enemy minion enters your deck, it becomes a friendly minion. So, by the time the After a Card is Played event occurs, Djinni’s trigger is valid, because the minion is now friendly.
After the mechanics update, Djinni’s trigger is validated at the beginning of the sequence when the enemy minion is still on the battlefield, and because the triggerisn’t valid at that point (since Entomb counts as being cast on an enemy minion), it’s prevented from triggering when the After a Card is Played event occurs.
There is one final change we should mention, which is a tweak to when we validate triggers across different zones. Currently, the order in which triggers are validatedand activated looks like this:
1) Validate Player 1 Battlefield triggers and then activate those that are valid.
2) Validate Player 1 Hand triggers and then activate those that are valid.
3) Validate Player 1 Deck triggers and then activate those that are valid.
4) Validate Player 2 Battlefield triggers and then activate those that are valid.
5) Validate Player 2 Hand triggers and then activate those that are valid.
6) Validate Player 2 Deck triggers and then activate those that are valid.
That approach meant new triggers could appear in the middle of a sequence and still be activated, and a trigger’s validation could even be affected by previous triggers’activations. The Bolvar Fordragon/Spirit Echo interaction detailed in the video was an example of a weird interaction caused by this.
After the update, the order now looks like this:
1) Validate all Battlefield triggers
2) Validate all Hand triggers
3) Validate all Deck triggers
4) Activate Player 1 valid Battlefield triggers
5) Activate Player 1 valid Hand triggers
6) Activate Player 1 valid Deck triggers
7) Activate Player 2 valid Battlefield triggers
8) Activate Player 2 valid Hand triggers
9) Activate Player 2 valid Deck triggers
This means all triggers are validated before any trigger is allowed to activate. Since all triggers are validated using the same game state, then triggers that appear in the middle aren’t allowed to fire. It’s important to note that the order in which triggersare activated is unchanged.
Here are some more examples of sequences and their results before and after the mechanics update:
Card Played
Example Interaction:
Player 1 has a Mad Scientist on the board, and a Mirror Entity in their deck.
Player 2 plays Stampeding Kodo.
Before Update
1) Stampeding Kodo kills Mad Scientist.
2) Mad Scientist pulls Mirror Entity into play.
3) Mirror Entity triggers, copying Stampeding Kodo.
After Update
1) Stampeding Kodo kills Mad Scientist.
2) Mad Scientist pulls Mirror Entity into play.
3) Mirror Entity does NOT trigger, because it did not exist when Stampeding Kodo was played.
Minion Destroyed
Example Interaction:
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 spawn a Cult Master from its Deathrattle.
Before Update:
The Cult Master's power triggers off of the Wisp's death, and Player 1 draws a card.
After Update:
The Cult Master does not trigger off the Wisp's death, because it wasn’t present to see the Wisp destroyed.
Summon Minion
Example Interaction:
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.
Before Update:
Spirit Singer Umbra triggers off the Savannah Highmane and summons two hyenas.
After Update:
Spiritsinger Umbra does not trigger off the Savannah Highmane, because she was not present when Savannah Highmane was played.
Thanks for Reading!
Of course, our work to make Hearthstone better won’t stop here!
Like the majority of odd interactions, each of these situations represents an edge case. While this update will address every situation we illustrated (among many others), there are still bound to be more. Keep in mind these are substantial changes to the core systems that underlie Hearthstone! We need to make them incrementally, and with the utmost care, but you can rest assured that we’ll continue to make improvements over time.
Well, Imp gang boos activates first anyway, then the shreder dies, so no, knife juggler won't activate
All I want to know is will Potion of Polymorph block Battlecry effects now.
Potion of Polymorph specificaly states AFTER you play a minion, so it is not supposed to do it
Just wanted to quick-check the changes. Didn't expect a one hour reading comprehension haha.
Will be back^^
TL:DR
i would like to say i didn't read the update because its too long but i agree anyways, thank you !
Really wonder why Unlicensed Apothecary triggers after evolve while Addled Grizzly doesn't.
Probably because Addled Grizzly says "After you summon..." and not "Whenever you summon..." like Apothecary.
And Doomsayer should be removed from the Evolve results , thanks, it'll clear my board 😃😄
Apothecary got shut down is good news, once he gave me 25 damages after Evolve 😆
Doomsayer is a risk that you have to accept or play around with Evolve. Unlicensed Apothecary is still usually a bad outcome, and still possible. They just prevented it from damaging you for every minion you evolve, because that violates what the card text states. Evolve minions are not "summoned" any more than a Polymorph Sheep is.
It was worth it for them to fix it now, because the next expansion has a lot of new cards that would be unintuitive without the fixes.
Glad to see this. It was very frustrating to lose because of these bizarre, unpredictable and often nonsense interactions. There should be far fewer of them after these changes.
Does this change the fact that Defile can activate Deathrattles and then kill them? I.E. using Possessed Villager before Defile to guarantee three damage. Or does the re-casting of Defile count as an entirely new event each time?
I would not think so since defile reads "if this kills a minion cast this again" so it has to actually kill the minion before it can cast again which is why a minion can not drop to negative hit points with defile, so deathrattle affects happen when the minion dies, and if defile has to kill it first than I would think that it would still work the same.
Defile deals 1 damage to everything, check Take Damage and Death Triggers, Resolve Those, Check Defile Condition and if valid, Defile deals 1 damage to everything. Repeat.
Note that defile is never CAST AGAIN, otherwise Violet Teacher would always spit out 1/1s killing everything up to 6 health without a question.
The only difference is that spells cast by other cards do not activate spell effects. Eg: Yogg-Saron, Hope's End does not buff Mana Wyrm. The Defiles after the first are cast by Defile, not by the player, so they do not create Violet Apprentices, activate Flamewaker, etc.
Let me just clarify something though..
With this change, imagine a Wild Pyromancer on 1 health. I cast Power Word:Shield on it, rather than going to a 3/3, then burning the board and being a 3/2 it will die and my spell will not do anything ? Or will it go to 3/0, then 3/2?
Doesn't Wold Pyro activate its effect after a spell is cast? So it should still the the same.
PW:S resolves first and then it casts the AOE. Same as it does now.
As someone who is used to the stack in magic, this is much less intuitive. Being able to chain effects is much more fun/epic than "whatever was there when it started is the state".