What Are the Implications of the Recent Discover Mechanic Changes?

The latest patch has pre-loaded the upcoming Saviors of Uldum solo content (Tombs of Terror), fixed some bugs… Oh, and it also had a short notice about making a massive change to one of the most popular mechanics in the entire game. Wait, what? Yes – I’m absolutely surprised that Blizzard ended up writing only three sentences about how the Discover keyword is going to work now instead of dedicating an entire blog post to it and explaining their intentions. Because it’s not a small update that will not matter – it’s significant enough that it might make some previously strong cards much weaker. Or – in some rare cases – more powerful.

Given that the changes were applied to the entire mechanic, and not only cards that are out right now, it also has huge implications for the future. We’re getting a bunch of new Discover cards in every set, and at least a part of them will be affected. It means that they will now be able to get away with making some Discover cards a bit stronger without worrying about a certain class abusing them. No matter how you look at it, it’s a big change that lots of people already asked for in the past.

The Old vs the New Discover

Let’s talk quickly about what exactly changes. Before this patch, each Discover card that could give you cards from pool of both Neutral and Class cards (so a bunch of them) gave you the latter more commonly. To be precise, each Class card had a 400% chance to appear compared to a Neutral card. After the patch, this bonus will no longer be present. It means that every single card has exactly the same chance of being Discovered.

It doesn’t means that Class cards will have exactly 4x lower chance to appear right now than they did in the past. Depending on the exact card pool etc. they will now, on average, appear ~2.5 times less often. Which is still a lot.

But why does it matter, exactly? Why is it a nerf? That’s because, on average, class cards are more powerful than neutral cards. There are less “filler” class cards than neutrals. There are also much more specific, high priority picks among class cards. Getting them way less consistently will be a huge downside. The cards that could previously give you either a class or neutral card will now offer neutral cards more often. Which, most of the time, is bad. But we’ve also got two examples of cards that will become stronger after the changes!

Most of Discover Cards Won’t Be Affected

However, no need to panic – it’s very likely that the decks you play won’t even be affected. The truth is that while the changes have big implications on anything that can discover both neutral and class cards, those are in the minority right now. Looking through the list of Discover cards, I was surprised how little of those we’ve got lately.

Currently, most of the Discover cards already pull from a much narrower pool of cards. For example – anything that Discovers a spell is already limited to class cards, simply because there are no neutral spells in the game (yet). It means that cards like Firetree Witchdoctor, Vulpera Scoundrel or Haunting Visions simply won’t be affected. Some other cards specifically state the class they discover from – e.g. Messenger Raven or Crystalsong Portal. Discovering a Secret (Secret Plan, Arcane Keysmith) is also, obviously, pulling only from class cards. Then we have even more specific Discovers – getting a Lackey (Sinister Deal), Choose One card (Worthy Expedition) or a minion that died this game (Body Wrapper, Nine Lives) will remain exactly the same. If my count is correct, we have 34 different Discover cards in Standard. Out of those, only 11 will be affected (plus two more cards in which only a part of them is affected). And some of them haven’t seen any play in the first place, so making them weaker will have no impact on the game whatsoever.

Of course, Discover cards aren’t only present in the current Standard format. In the past, we had a bunch of very popular cards that would be affected. For example – Dark Peddler, Raven Idol, Museum Curator, Netherspite Historian, Stonehill Defender or Free From Amber have seen a lot of play when they were in Standard. Does it mean that a bunch of decks in Wild will be nerfed? Well, not exactly. Times have changed, Wild’s power level is pretty high compared to Standard, and most of those cards simply aren’t played anymore. You can still see some of them here and there (e.g. Netherspite Historian is played in Dragon Priest and Stonehill Defender is used in Taunt Warrior), but they aren’t nearly as impactful as you might remember them being. So while the changes will have a slight impact on the Wild format, we probably won’t see any heavy meta shifts.

All of that said, there are a few cards that will get significantly weaker after the nerfs. So how big of an impact will those have?

Hidden Warrior Nerf

Interestingly enough, a class that will be most affected by the changes in the current Standard format will be… Warrior. Majority of the popular changed Discover cards are either Warrior class cards or are commonly seen in Warrior. The class that dodged severe nerfs last patch, with only Dr. Boom, Mad Genius getting his mana cost upped (which obviously mattered, but didn’t change the deck’s power as much as a lot of players would want) is now getting indirectly nerfed. Coincidence? I’ll let you decide.

Let’s start with the most important one – Discovering Mechs. It’s a big part of the current Control Warrior’s power and possibly the main reason why players hate the “Created By” meta. Warriors have two ways to discover Mechs – Omega Assembly, as well as Dr. Boom’s Hero Power Delivery Drone. Pool of Mechs is actually quite big, but the truth is that a lot of the Neutral ones are simply bad or at least not impactful enough at the time you use your Discover effects (late game). Faithful Lumi, Mecharoo, Skaterbot, Galvanizer, Spark Engine, Unpowered Mauler, Alarm-o-Bot, Demolisher or Spring Rocket are great examples of minions that you don’t really want to get in the late game. Even among the higher cost Mechs, there are a bunch of cards that are “meh” or straight up bad – e.g. Spark Drill or Unpowered Steambot. Roughly 1/3 of Neutral Mechs could be considered “good” picks, even less of them are really “premium” cards that you really want to get (~1/5). On the other hand, let’s look at the Warrior class Mechs. Eternium Rover, Vicious Scraphound, Clockwork Goblin, Omega Devastator, Dyn-o-matic, Security Rover, Beryllium Nullifier, Tomb Warden and The Boom Reaver. Out of those nine Mechs, only the two first are not great in the late game – and even they are significantly better than their Neutral counterparts (plus gaining Armor is pretty important in some matchups, so you might end up picking them over other theoretically better options from time to time). That’s 7 out of 9 great picks (and 3-4 of those are absolute premium picks), a ratio significantly higher than among Neutral cards.

Before the changes, a chance to discover any specific Class Mech used to be 16.29%. After the changes, the chance will be the same as discovering any other Mech in the game and will go down to 6.67%. It means that we should see ~2.44 times less Warrior Mechs discovered on average. To put it simply, situations in which your opponent got fourth or fifth Omega Devastator should now be significantly less common. It might not seem like much, but this is a big hit to both Omega Assembly as well as Dr. Boom, which drew much of its power in slower matchups from discovering powerful Mechs.

But that’s not everything. Another card affected by the changes also belongs to Warrior – Frightened Flunky. Once again, a pool of Taunt cards is vast and they vary in power level heavily. However, if we look at the pool of Warrior class Taunts, we have – you guessed it – only good picks: Frightened Flunky, Armagedillo and Tomb Warden. I’ve played some Control Warrior in Saviors of Uldum and I have to say that getting another Armagedillo or Tomb Warden often won me the match. Even getting another Flunky is extra body for free in slower matchup as well as a chance to re-roll. Now Flunky will be way less consistent, maybe even to the point of removing him from the deck. With Flunky gone, there’s a chance that the entire Taunt package will have to go. Alternatively, players might not make any changes, but in either case, power level of the deck will go down.

And last, but not least, another card affected by the nerfs is actually Archivist Elysiana. While it doesn’t work like a regular Discover card (putting whatever you pick into your hand), it follows the same rules – class cards were still weighed at 400%, meaning that you (in this case) used to get Warrior cards more often than neutrals. Given that, just like I’ve mentioned already, class cards are on average stronger than neutrals, you often preferred them. If you could pick only from class cards instead of neutrals, you’d gladly do it. After the patch, an average deck created with Elysiana will contain less class cards, meaning that it will be slightly weaker. Of course, you always ended up with a bunch of weird and not necessarily useful cards after playing Elysiana, but now you will have more of those on average. Considering that Elysiana herself is neutral, it’s not a direct nerf to the Warrior, but the truth is that Warrior is the class that uses her far more often than any other. The only other build using Elysiana right now is Control Shaman, which is an off-meta deck (<0.5% popularity compared to the Control Warrior’s ~6%).

Other Affected Cards

Without a doubt, Warrior class will be the one most affected by the patch. I suspect that Control Warrior’s win rate is going to drop measurably – probably not enough to disappear from the meta completely, which is obviously good (like it or hate it, diversity is important and Control Warrior is one of the only Control decks left in Standard right now). But Warrior cards aren’t the only ones getting changed. Here’s the list of other cards that have became weaker after the patch (in alphabetic order):

  • Blazing Invocation – Not really played in actual Shaman decks. Sometimes discovered from Ethereal Lackey or generated by Hagatha the Witch, but that’s about it. In case you end up getting it, the most significant change is a reduced chance of seeing Shudderwock, which was usually the best pick from Blazing Invocation.
  • Dark Possession – We don’t have many Neutral Demons, so you’re still much more likely to get a Warlock one. But it’s worth noting that Neutral Demons are pretty bad on average – you get options like Felsoul Inquisitor, Mad Summoner or Vilefiend, which don’t really want to pick. So, on average, it’s a nerf – although the card doesn’t see any play right now, so it will be irrelevant for now.
  • Golden Scarab – It’s getting significantly weaker – before patch the only reason to play it would be putting it in a class with really strong 4 mana cards to take advantage of the bonus. Still, the card is nowhere to be seen outside of being randomly generated once in a blue moon (unlike its League of Explorers counterpart – Jeweled Scarab – which has seen at least SOME play in Shaman thanks to the offering bonus).
  • Griftah – Mostly a meme Legendary – once again, virtually no one is putting it into their decks. However, if you do play it for some reason, it is getting slightly weaker. Highly synergistic class cards were usually the best picks from Griftah – if you got them, then you could use them to their fullest extent. If your opponent got them – it’s not that big of a loss, because he might not have the necessary synergies. A perfect example would be Rogue and Deadly Poison vs class without a weapon.
  • Heistbaron Togwaggle (or more specifically one of its treasures – Zarog's Crown) – Togwaggle actually DOES see some play, and Zarog’s Crown is a commonly picked treasure, so the changes will make an impact here. However, it’s one of those rare cases in which new Discover weighing will actually be a buff. Given that summoning does not trigger Battlecries or Combos, Rogue Legendaries are usually much worse to pick than Neutral ones. Edwin VanCleef, Face Collector and Gral, the Shark are vanilla 2/2’s. Myra Rotspring and Captain Hooktusk are also way below average. Even the higher stat ones are either 5/5’s (Heistbaron Togwaggle, Anka, the Buried) or 6/6’s (Tess Greymane, Tak Nozwhisker), which is still only an average outcome. It’s one of the rare cases in which picking a Neutral card is preferable most of the times.
  • Myra Rotspring – Myra has seen some play in Deathrattle Rogue before rotation, when Carnivorous Cube was still around. Given that Deathrattle Rogue is not a thing in this expansion, the card sees no play. But even if it did, it wouldn’t make much of an impact, as Rogue Deathrattle cards are rather average.
  • A New Challenger... –  The card sees some niche play, but in the current Standard format the changes matter only in theory, as Paladin has no 6 mana cost minion anyway. It might matter if Paladin gets a strong or weak 6 mana minion next expansion, but probably won’t make or break the card anyway.
  • Gurubashi Hypemon – Rogue has some interesting Battlecry minions to pick from, so the card’s power level should go down on average. However, there’s no one to test it, as the card sees absolutely no play.
  • Power of Creation – Just like in case of Togwaggle, this one is actually a buff to the card. Right now, Mage has four different 6 mana minions in Standard – Arcanosaur, Meteorologist, Reno the Relicologist and Toki, Time-Tinker. The former two are literally the worst minions you can roll, while the latter two are pretty average outcomes. The fact that they are offered more commonly makes getting premium Neutral options such as Damaged Stegotron, Boulderfist Ogre, Sunwalker or Cairne Bloodhoof less likely. It also made picking Power of Creation from Tortollan Pilgrim significantly worse, because you couldn’t even pick so you often got the worst option. It would matter much more if Highlander Mage wasn’t nerfed in the last patch, but hey, the card is still playable and will remain in Standard all the way until 2021, so it’s a significant change.


A Hearthstone player and writer from Poland, Stonekeep has been in a love-hate relationship with Hearthstone since Closed Beta. Over that time, he has achieved many high Legend climbs and infinite Arena runs. He's the current admin of Hearthstone Top Decks.

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Leave a Reply


  1. CryoCasper
    September 12, 2019 at 6:08 am

    All the cards you say that see no play (like Hypemon) I play. Sooooo.

    • Stonekeep - Site Admin
      September 12, 2019 at 6:15 am

      Every single card in Hearthstone is played by at least hundreds, and probably even thousands of players. It’s a game played by millions of players, after all. But the term “sees play” is referring to more popular, usually meta builds (or at least more well known off-meta decks).

  2. SlapLaB
    September 11, 2019 at 1:49 pm

    Actually it does affect Arena quite a bit too (Golden Scarab for example is a common pick).

  3. PitLord
    September 11, 2019 at 4:00 am

    Personally, i would have also canceled the possibility to discover herself again & again & again. Sure probability are much less now for minion that discover minion, but not for spell that discover spell that remain immutate (example primordial glyph in wild).

    • MilesTegF
      September 11, 2019 at 5:54 am

      I’d say that is not that relevant in spell discovering spell as it is on minion discovering minion.. That is only really valuable if you have a synergy going (like having a Dune Sculptor or a Magic Dart Frog on board for example). Cos if not, you are only paying mana for the chance of getting a better choice on the next cast. Minion discovering minion on the other hand (like messenger raven or Flunkly) has the advantadge that even if you have no synergy associated with summoning minions (like knife juggler) at least you are gaining the extra body on board.

  4. KaihatsuJai
    September 11, 2019 at 1:38 am

    Great article, thank you!

  5. GlosuuLang
    September 11, 2019 at 1:15 am

    Hey Stonekeep! So I was advocating that Discover should reveal the chosen option to the opponent so that they at least know what to play around.You said that was a considerable nerf and that Blizzard would never do that because they would have to give dust to everyone for every Discover card. … And now they nerf Discover to not give bonus to class cards! I believe this is an equivalent nerf (i.e. just a slight nerf, not a big one), and yet Blizzard is not giving anything! We should fight for Discover revealing the choice to the opponent!

    • Stonekeep - Site Admin
      September 11, 2019 at 3:21 am

      I stand by my previous point. This change is way less severe nerf than revealing a discovered card to the opponent. Not only it affects a part of the Discover cards (roughly ~1/3), but I’d argue that it reduces their power level less than the “reveal” nerf. Revealing a card to the opponent would make every single Discover card way worse. Hand prediction is one of the most important skills in Hearthstone – if you know what your opponent has in hand, you can play around it. That’s what often separates bad from good players. The best players in the game are the best exactly because they more or less know what the opponent’s hand could be at every time. But it only applies to cards that started in their deck – when it comes to Discovers, you can never really account for those, since they can often be anything. A big part of power behind Discover mechanic is flexibility and unpredictability. The second biggest reason to play Discover cards would be gone completely if that happened.

      While it’s hard to put exact numbers of those, to illustrate my opinion – this nerf is a ~4/10 nerf and it only affects roughly 1/3 of Discover cards. Your idea would be a ~7/10 nerf and it would affect basically every Discover card in the game.

      However, I’m already surprised that more players aren’t demanding Dust for those changes. I remember everyone on reddit saying that they want Dust when Rogue’s Quest had a “consistency change” recently, which was also a clear nerf to the card. Right now a lot of powerful cards are getting weaker. My guess is that people are (like always) approaching the subject emotionally and they’re happy with this one since they hate Control Warrior, and Control Warrior is the deck that got affected most.

  6. Axeliloadi
    September 10, 2019 at 9:42 pm

    Great article! I didn’t actually consider this would buff some cards.
    Also couldn’t help but notice a minor error:
    Security rover is actually not a taunt minion by itself 🙂

    • Stonekeep - Site Admin
      September 11, 2019 at 3:00 am

      Fixed it, thanks. I was writing it around 2-3 am so my mind wasn’t completely clear :p