The Discover mechanic was added to Hearthstone in November 2015 in the League of Explorers adventure. The mechanic immediately became a fan favorite and one of the cornerstones of the game. With Discover, the player chooses one of three cards from a pre-determined pool of options that is then usually added to their hand, unless the Discover card specifies otherwise. It is a delicate balance between randomness and agency that takes full advantage of the digital nature of Hearthstone. In 2015, this was a ground-breaking development that was something completely new and unique to Hearthstone and did a great deal to separate the game from physical card games.
The History of Discover Cards
In its original version, Discover had a significant additional weight for class cards. Each class card in the pool was four times as likely to appear as an option than any Neutral card. This preferential treatment was there to ensure that people would see class cards often enough, as most pools had far more Neutral cards than class cards. The system was changed in September 2019 with the launch of Saviors of Uldum, after which all cards have been as likely to appear as options.
The launch lineup of Discover cards from League of Explorers is an impressive one:
- Dark Peddler
- Ethereal Conjurer
- Gorillabot A-3
- Jeweled Scarab
- Museum Curator
- Raven Idol
- Tomb Spider
- Arch-Thief Rafaam
- Sir Finley Mrrgglton
Almost all of these cards have seen competitive play! Furthermore, multiple of these cards have been reprinted in the Core set and have seen competitive play in the Standard format again years after their launch. None of them are quite strong enough to be Wild staples, although Gorillabot A-3 is still played in some Mech decks in the evergreen format as well.
Overall, Hearthstone has 194 Discover cards at the moment:
- 9 from 2015 (League of Explorers)
- 10 from 2016
- 14 from 2017
- 17 from 2018
- 32 from 2019
- 23 from 2020
- 25 from 2021
- 34 from 2022
- 15 from 2023 (Festival of Legends)
The number of Discover cards started to increase slowly, but it has generally been on the rise. The most Discover cards were printed in 2022 and Festival of Legends is the expansion with the most Discover cards in it since the beginning of Hearthstone. If you feel like there are lots of Discovers going on in your games, its increasing prevalence in the card pool plays a part. There has never been as large a share of Discover cards in the Standard format as there is right now! When counting the Core set cards, there are 73 Discover cards in the Standard format at the moment!
As Blizzard has kept refining the mechanic, they have largely altered two things:
First, the source where you Discover cards from. This can be a generated pool with specific options (mana cost, mechanic, card type, minion type) or a specific pool (your deck, your opponent’s hand, dead minions, cast spells). There are lots of options where your Discovered cards come from, all the way to using the mechanic for a sideboard-like function with E.T.C., Band Manager.
Second, the thing that happens to the Discovered card. Most of them are added to your hand, but some are summoned or played immediately, and sometimes there are additional effects like reducing the mana cost of the cards.
Is Discover a Problem Now?
Discover cards are more popular than ever. Three of the top-5 most popular cards in Standard are Discover cards: School Teacher, Nerubian Vizier, and Amalgam of the Deep. There is more and more resource generation in the game and many games end up decided by the Discovered cards. It is getting a little overwhelming when it is repeated game after game.
Blizzard took a step to address the issue when they changed the rules in the balance patch so that triple-rune Death Knight cards can no longer be Discovered. This has slightly weakened the mechanic in the Standard format, but it only touches one class.
If we examine the performance of Discover cards in a bit more detail, some general characteristics begin to emerge.
First, Death Knight cards are really, really strong. Death Knight was introduced in the final expansion of the last Standard year, and it had to be competitive with other classes right from the start. With a smaller card pool, the class was given a higher density of strong cards. Do you know which mechanic can abuse a high density of strong cards? Yeah, that’s Discover. Weak outcomes are practically eliminated when you get to choose from three cards and the overall pool is strong enough.
Death Knight is the primary class that makes use of School Teacher and Nerubian Vizier, but also the performance of Discover cards like Hematurge and Frost Strike is particularly strong. Both Hematurge and Frost Strike Discover from a pool of a single rune, which further limits the number of options, leaves behind an even stronger card pool, and makes the cards extremely consistent in finding the right answers. This is what Blizzard attempted to answer with the Discover rule change for Death Knight but with limited success.
Second, combining Discover with cost reduction is powerful. School Teacher, Nerubian Vizier, and Illidari Studies all enable you to play the Discovered cards later at a lower cost. They are also some of the most popular and most powerful Discover cards. Finding just the right tools and making them cheaper is a proposition few can afford to ignore. We are also starting to see Nellie, the Great Thresher finding its way back to the meta in Menagerie Warrior, partially because of the tempo it provides, and partially because of its specific Discover pool.
Third, small Discover pools can provide far too consistent results, especially when one of the options is much more powerful than the others. I am talking about The One-Amalgam Band here. If you play a Menagerie deck and use Amalgam of the Deep on a Quilboar, you will find The One-Amalgam Band most of the time. As an Amalgam, it is also a Quilboar, and there are only a couple of real Quilboar in the game. The One-Amalgam Band is also a Pirate, and when you get three attempts to find it with Nellie, you often find a copy. We see a similar effect with Taste of Chaos in Big Demon Hunter Discovering additional copies of All Fel Breaks Loose with scary accuracy.
We also have many Discover cards that are strong but that cannot be described as oppressive. Cards like Muckborn Servant, Paparazzi, Sketchy Stranger, and Faithful Companions are worthy additions to decks and make them better without being too dominant.
Discover as a mechanic is great. It is one of Hearthstone’s main innovations that separates the game from physical-first card games. However, Discover cards require careful management. Even seemingly average Discover cards can become oppressive if their Discover pool provides options that are too strong. It is a careful balancing act to ensure that the pool does not have too strong outliers but also does not become too diluted and random to preserve the power of Discover. This planning needs to extend to the entire expansion and to entire formats, far beyond the individual cards, and that makes it so challenging.
The Death Knight Discover rule change that removed triple-rune cards from the pool was a bandaid to fix Discover pools that had gotten out of control. It is an arbitrary limitation that shows how Blizzard had failed in overall Discover balancing in this case. It might still be necessary as they work their way out. Creating something great is not easy. Still, preserving a feature that separates Hearthstone from its competitors is worth the effort.
Related to Discover cards, but also many other strong cards, mana cost reduction is another theme that needs careful monitoring. This is a more simple task, as it happens directly with specific cards and can be changed at will by changing those cards. Nonetheless, it takes constant vigilance to keep it under control.
Time to Play with Discover!
If you want to play with some Discover cards after reading this, here are some of the top decks that prominently feature Discover cards.
While weaker than Unholy Death Knight, Blood Death Knight is the most popular deck with a large number of Discover cards in the current meta. This version includes Sketchy Strangers, and I love them in this archetype:
- 1Righteous Protector2
- 1Sanguine Soldier2
- 1Sinful Sous Chef2
- 2Blood Matriarch Liadrin1
- 2Class Action Lawyer2
- 2For Quel’Thalas!2
- 2Hand of A’dal2
- 2Kotori Lightblade1
- 2Order in the Court1
- 3Boogie Down2
- 3Disco Maul2
- 3Muckborn Servant2
- 3Seal of Blood2
- 6The Purator1
- 7The Countess1
- 10The Garden’s Grace2
Aggressive Hunter decks are currently moving towards Collateral Damage builds or even cutting all the most expensive cards and topping out with Queen Azshara, but there are still some Faithful Companions around as well:
The most Discover-heavy deck in the current Standard format is Spooky Mage, which is attempting to come back to the meta with Grand Magister Rommath. The success of this comeback attempt is yet to be seen, but the early numbers indicate an over 50% win rate:
Finally, the latest attempt to make Menagerie Warrior work – and it looks promising – is to add Nellie, the Great Thresher into the deck: