Discover

Discover
Choose one of three cards to add to your hand.

Add a Taunt minion to your hand that is neutral or from the class of your hero.

Discover is an ability that allows the player to choose one of three different cards. The three cards are randomly selected from a pool of all eligible cards, as stated by the card text. If not stated, the pool of cards consists of all eligible neutral and class cards matching the player's current hero class, with neutral and class cards weighted equally in being selected. By default, the chosen card is then generated and added to the player's hand, unless otherwise specified in the card text.

All Discover effects feature card selections restricted to specific criteria. Some examples are listed below:

Stonehill Defender allows the player to add a Taunt minion to their hand.
Primordial Glyph allows the player to add a spell to their hand.
Golden Scarab allows the player to add a 4-cost card to their hand.
Arch-Thief Rafaam offers the player a specific selection of unique uncollectible cards to add to their hand.
Shadow Visions allows the player to add a copy of a spell from their deck to their hand.
Cleric of Scales allows the player to draw the selected spell from their deck.

Some Discover effects do not generate cards to the hand and instead have other effects as specified in the card text. Some examples are listed below:

Free From Amber allows the player to summon a minion that costs 8 or more.
Tortollan Primalist allows the player to cast a spell with random targets.
Sir Finley Mrrgglton/Sir Finley of the Sands offers Hero Powers from any class to replace the player's current Hero Power.
Master's Call allows the player to draw one or three minions from their deck.

The Discover effect involves both elements of RNG and strategy, with players having to strategize and predict what they can get out of their Discover effect to impact the board and win the game.

Notes[edit]

Discover in action

The Discover effect allows the player to choose a card from a selection of three cards. The cards offered are either neutral or from the class of the player's current hero. If there are additional requirements for the selection of the three cards specified in the card text, those conditions are met as well.
- Tri-class Discover effects like Lotus Agents offer one random option from each of the three specified classes, regardless of the player's current class; no neutral options are presented.
- Any card which discovers from a hand or deck has an equal chance to discover neutral and class cards, such as Madame Lazul, Tracking, and Cloning Device.
The Discover effect by default adds the selected card to the player's hand. However, some cards have an explicit description in the card text of what will be done with the selected card instead.
Discover effects will not present duplicate options: each of the three possible choices will be different.^[1]
Players cannot choose not to take one of the cards offered by a Discover effect. They must choose one of the options.^[2]^[3] If, however, the turn timer expires before one of the Discover options is picked, a random option will be chosen.
While the activation of Discover effects can be duplicated by Brann Bronzebeard, individual Discover events cannot. If a Discover effect is duplicated, the two will be separate events, with their own selections of cards.^[4] However, there is no special rule preventing the two Discovers from featuring some of the same options simply by chance.^[5]
The card chosen by the Discover effect is not placed in your hand until the end of the current Sequence, meaning that it is possible for your hand to become full in the meantime, discarding the card you chose. For example, if you have a 10/10 card hand, play Raven Idol and have a Wild Pyromancer and Acolyte of Pain in play, the card chosen will float in the air, Acolyte of Pain triggering off of Wild Pyromancer's damage will fill your hand, and finally the card chosen will be discarded. ^[6] Another way to pull of this combo is by casting a Discover spell with a 10/10 hand a Gadgetzan Auctioneer in play.
If you play a Discover Battlecry minion, the first Discover effect will not put its card in your hand until the end of the current Sequence (e.g. after death processing following the After Summon Phase resolves). Then, if you control Brann Bronzebeard, you will get a second Discover effect. Note that the played minion does not have to be alive at this time, only Brann Bronzebeard does. Also, note that normally Brann Bronzebeard has to be in your control during the Battlecry Phase.^[7]
If a secret is discovered as a class without secrets in the format, then a random secret from the class of the card itself is discovered. Otherwise, a secret from the player's current class is discovered.^[8]
Using Discover effects as Lord Jaraxxus or any Hero card offers cards as though you were playing as the class that card originated from.
However, using Discover effects as the Ragnaros hero has a different behaviour depending on the card.^[9]
- If the card with the Discover effect is a neutral card, the game randomly picks 1 of the 9 classes and offers you cards as though you played the Discover card as that class.
- If the card with the Discover effect is a class card, the game offers you cards as though you played the Discover card as that class.
Cards that Discover a card in your deck, like Master's Call or Cleric of Scales, will draw the card. If the card says "Discover a copy of a card in your deck", such as Stitched Tracker, will create an extra copy.
Cards are only considered Discover effects when they say Discover on their card text. Discover-like effects such as Build-A-Beast, Swampqueen Hagatha, and Zephrys the Great will not benefit from Discover synergies.
Cards that Discover random cards cannot Discover a copy of itself.

Cards[edit]

Collectible[edit]

This section lists all collectible cards that have the Discover mechanic.

For Wild format listings, see Discover/Wild format

Name / Desc	Rarity	Type	Subtype	Class	Cost	Atk	HP	Description
Athletic Studies	Common	Spell		Warrior	1			Discover a Rush minion. Your next one costs (1) less. It's a quick read.
Boom Squad	Common	Spell		Warrior	1			Discover a Lackey, Mech, or Dragon. Discover the meaning of squad goals.
Carrion Studies	Common	Spell		Hunter	1			Discover a Deathrattle minion. Your next one costs (1) less. A good read but a little too much fluff.
Demonic Studies	Common	Spell		Warlock	1			Discover a Demon. Your next one costs (1) less. "Do you wanna summon a demon? I wanna summon a demon!"
Draconic Studies	Common	Spell		Priest	1			Discover a Dragon. Your next one costs (1) less. Our Draconic Studies program has a high rate of burnout.
Nature Studies	Common	Spell		Druid	1			Discover a spell. Your next one costs (1) less. "I have a first edition! Go ahead, count the rings."
Primordial Studies	Common	Spell			1			Discover a Spell Damage minion. Your next one costs (1) less. A long forgotten tome whose very essence seeps of magic. 40 dust, used.
Renew	Common	Spell		Priest	1			Restore 3 Health. Discover a spell. I am rejuvenated, I am renewed, I am my own nightlight!
Sinister Deal	Common	Spell		Warlock	1			Discover a Lackey. "So, what's in the sack?" "Something... sinister." "Okay, it's a deal."
Wand Thief	Common	Minion	General		1	1	2	Combo: Discover a Mage spell. "What’re ya buyin’?”
Worthy Expedition	Common	Spell		Druid	1			Discover a Choose One card. This isn't where I parked my mount.
Frightened Flunky	Common	Minion	General	Warrior	2	2	2	Taunt Battlecry: Discover a Taunt minion. Some people just aren't cut out to be supervillain material.
Netherwalker	Common	Minion	General	Demon Hunter	2	2	2	Battlecry: Discover a Demon. You got to Nethercrawl before you can Netherwalk.
Twisted Knowledge	Common	Spell		Warlock	2			Discover 2 Warlock cards. People eat eight spiders in their sleep per year. Centaurs have two rib cages. Dwarves are just counterfeit titans.
Waxmancy	Common	Spell		Rogue	2			Discover a Battlecry minion. Reduce its Cost by (2). The waxmancer works with flame and form, giving shape to figures warm. Some think he's a crazy creeper, but crafting minions is simply cheaper.
Bronze Explorer	Common	Minion	Dragon	Paladin	3	2	3	Lifesteal Battlecry: Discover a Dragon. Always ready to explore new friendships! Except with Deathwing.
Golden Scarab	Common	Minion	Beast	Any	3	2	2	Battlecry: Discover a 4-Cost card. Who actually puts all the gold plating on these things, and why?
Marshspawn	Common	Minion	Elemental	Shaman	3	3	4	Battlecry: If you cast a spell last turn, Discover a spell. Hopes to someday promote to Marshsqueen.
Messenger Raven	Common	Minion	Beast	Mage	3	3	2	Battlecry: Discover a Mage minion. You can make a collect CAW!
Primordial Explorer	Common	Minion	Dragon	Hunter	3	2	3	Poisonous Battlecry: Discover a Dragon. "We're letting the poisonous dude carry the bags?"
Azure Explorer	Common	Minion	Dragon	Mage	4	2	3	Spell Damage +2 Battlecry: Discover a Dragon. Has an appetite for knowledge!
Hench-Clan Burglar	Common	Minion	Pirate	Rogue	4	4	3	Battlecry: Discover a spell from another class. She's more of a rat burglar.
Marked Shot	Common	Spell		Hunter	4			Deal 4 damage to a minion. Discover a spell. Obviously it's marked for greatness.
Steward of Scrolls	Common	Minion	Elemental	Any	5	4	4	Spell Damage +1 Battlecry: Discover a spell. Oh dang it, I spilled ink elemental all over my essay!
Emerald Explorer	Common	Minion	Dragon	Druid	6	4	8	Taunt Battlecry: Discover a Dragon. Make it a double dragon!
Arcane Breath	Rare	Spell		Mage	1			Deal 2 damage to a minion. If you're holding a Dragon, Discover a spell. One of many side effects from eating mana cookies.
Cleric of Scales	Rare	Minion	General	Priest	1	1	1	Battlecry: If you're holding a Dragon, Discover a spell from your deck. If she can't find a spell, it's a clerical error.
Dragon's Hoard	Rare	Spell		Rogue	1			Discover a Legendary minion from another class. The Alliance loves this hoard.
Font of Power	Rare	Spell		Mage	1			Discover a Mage minion. If your deck has no minions, keep all 3. It's Comic Sans.
Magic Trick	Rare	Spell		Mage	1			Discover a spell that costs (3) or less. The world is not ready for an illusion of this depth and intricacy!
Dark Prophecy	Rare	Spell		Priest	3			Discover a 2-Cost minion. Summon it and give it +3 Health. It's always a dark prophecy with Madame Lazul. Where's my happy, fluffy prophecy?!
Apexis Smuggler	Epic	Minion	General	Mage	2	2	3	After you play a Secret, Discover a spell. "S-secrets? I don't have any! Whoa, look, a spell!"
Crystalsong Portal	Epic	Spell		Druid	2			Discover a Druid minion. If you hand has no minions, keep all 3. Experience the draw of the wild!
Nine Lives	Epic	Spell		Hunter	3			Discover a friendly Deathrattle minion that died this game. Also trigger its Deathrattle. Beware the night of the living pets!
Vulpera Scoundrel	Epic	Minion	General	Any	3	2	3	Battlecry: Discover a spell or pick a mystery choice. A spell is a spell, but the mystery choice could be anything! (It's also a spell.)
Body Wrapper	Epic	Minion	General	Any	4	4	4	Battlecry: Discover a friendly minion that died this game. Shuffle it into your deck. She uses pickle slices for the eyes. Keeps them well-preserved.
Chromatic Egg	Epic	Minion	General	Any	5	0	3	Battlecry: Secretly Discover a Dragon to hatch into. Deathrattle: Hatch! Nefarian was known for creating two things: horrible monsters and excellent breakfasts.
Power of Creation	Epic	Spell		Mage	8			Discover a 6-Cost minion. Summon two copies of it. Mostly used for party tricks, to be honest.
Tortollan Pilgrim	Epic	Minion	General	Mage	8	5	5	Battlecry: Discover a copy of a spell in your deck and cast it with random targets. A tortollan made it to the desert!
Shadowjeweler Hanar	Legendary	Minion	General	Rogue	2	1	4	After you play a Secret, Discover a Secret from a different class. What is a shadowjeweler? A miserable little pile of secrets.
Sir Finley of the Sands	Legendary	Minion	Murloc	Paladin	2	2	3	Battlecry: If your deck has no duplicates, Discover an upgraded Hero Power. "The sands shall be my sea! And this scarab shall be my, er, strange and wriggly boat!"
Instructor Fireheart	Legendary	Minion	General	Shaman	3	3	3	Battlecry: Discover a spell that costs (1) or more. If you play it this turn, repeat this effect. When you have fire in your heart, even death can't stop you.
Madame Lazul	Legendary	Minion	General	Priest	3	3	2	Battlecry: Discover a copy of a card in your oppponent's hand. Of course she knows the future, she's been looking at your cards the WHOLE TIME!
Malygos, Aspect of Magic	Legendary	Minion	Dragon	Mage	5	2	8	Battlecry: If you're holding a Dragon, Discover an upgraded Mage spell. It's official. We can say Malygeese.
Archivist Elysiana	Legendary	Minion	General	Any	9	7	7	Battlecry: Discover 5 cards. Replace your deck with 2 copies of each. Your deck is just another organizational challenge to her.
Kalecgos	Legendary	Minion	Dragon	Mage	10	4	12	Your first spell each turn costs (0). Battlecry: Discover a spell. He was once the Aspect of Magic but gave it up to focus on cheap tricks.
Showing all 46 cards

Wild format

This section contains information exclusive to Wild format.

Name / Desc	Rarity	Type	Subtype	Class	Cost	Atk	HP	Description
Cloning Device	Common	Spell		Priest	1			Discover a copy of a minion in your opponent's deck. Zerek got sick of fighting over the remote.
Hallucination	Common	Spell		Rogue	1			Discover a card from your opponent's class. It's the good kind of hallucination.
I Know a Guy	Common	Spell		Warrior	1			Discover a Taunt minion. Well… a guy who knows a guy.
Raven Idol	Common	Spell		Druid	1			Choose One - Discover a minion; or Discover a spell. Was petrified when it found out it didn't make the cut for Azerothian Idol.
Secret Plan	Common	Spell		Hunter	1			Discover a Secret. The secret is... There is no plan!
A Light in the Darkness	Common	Spell		Paladin	2			Discover a minion. Give it +1/+1. Wait, how can you have a light in the dark? If you turn on a light while it’s dark, doesn’t that mean it’s no longer dark?
Dark Peddler	Common	Minion	General	Warlock	2	2	2	Battlecry: Discover a 1-Cost card. I'm offering you a bargain here! This amazing vacuum cleaner for your soul!
Hydrologist	Common	Minion	Murloc	Paladin	2	2	2	Battlecry: Discover a Secret. Murloc hydrologists are pretty rare. Most murloc undergrads pick computer science.
Jeweled Scarab	Common	Minion	Beast	Any	2	1	1	Battlecry: Discover a (3)-Cost card. It's amazing what you can do with super glue!
Museum Curator	Common	Minion	General	Priest	2	1	2	Battlecry: Discover a Deathrattle card. He is forever cursing the kids who climb on the rails and the evil archeologists who animate the exhibits.
Netherspite Historian	Common	Minion	General	Any	2	1	3	Battlecry: If you're holding a Dragon, Discover a Dragon. She can tell you all about the history of people not STANDING IN THE GREEN BEAM!
Stolen Steel	Common	Spell		Rogue	2			Discover a weapon (from another class). Because Thrall wouldn't lend me Doomhammer.
Primalfin Lookout	Common	Minion	Murloc	Any	3	3	2	Battlecry: If you control another Murloc, Discover a Murloc. Lookout is a self-appointed title that's mostly an excuse to beat things up.
Stitched Tracker	Common	Minion	General	Hunter	3	2	2	Battlecry: Discover a copy of a minion in your deck. He's just exercising his right to bear arms.
Gorillabot A-3	Common	Minion	Mech	Any	4	3	4	Battlecry: If you control another Mech, Discover a Mech. A-1 and A-2 went nuts, when they should have gone bolts.
Tomb Spider	Common	Minion	Beast	Any	4	3	3	Battlecry: Discover a Beast. Less serious than its cousin, the Grave Spider.
Ethereal Conjurer	Common	Minion	General	Mage	5	6	3	Battlecry: Discover a spell. Despite the name, he's a solid conjurer.
Blazing Invocation	Rare	Spell		Shaman	1			Discover a Battlecry minion. A lot of shaman have started vaping their invocations.
Dark Possession	Rare	Spell		Warlock	1			Deal 2 damage to a friendly character. Discover a Demon. Wanted on three counts of gnomish possession.
Journey Below	Rare	Spell		Rogue	1			Discover a Deathrattle card. Don't stop believing there's something below.
Omega Assembly	Rare	Spell		Warrior	1			Discover a Mech. If you have 10 Mana Crystals, keep all 3 cards. They told Dr. Boom he could only pick one. He disagreed.
Dendrologist	Rare	Minion	General	Druid	2	2	3	Battlecry: If you control a Treant, Discover a spell. He's teaching his little buddy to talk, but all it says is, "I am Gloop."
Firetree Witchdoctor	Rare	Minion	General	Any	2	2	2	Battlecry: If you're holding a Dragon, Discover a spell. If your tree is on fire - stop, drop, and troll.
Grimestreet Informant	Rare	Minion	General		2	1	1	Battlecry: Discover a Hunter, Paladin or Warrior card. "Naw, naw. You're talkin' about Grime BOULEVARD. I ain't know nuthin' 'bout that."
Bloodscalp Strategist	Rare	Minion	General	Hunter	3	2	4	Battlecry: If you have a weapon equipped, Discover a spell. “Shoot them in the face” is more of a tactic* than a strategy.*
Kabal Courier	Rare	Minion	General		3	2	2	Battlecry: Discover a Mage, Priest or Warlock card. Hey, you park your kodo under a harpy nest, you get what you deserve.
Stonehill Defender	Rare	Minion	General	Any	3	1	4	Taunt Battlecry: Discover a Taunt minion. Briefly tried stand-up comedy under the name "Stonehill Offender", but turtles are just too thin-skinned.
Eternal Servitude	Rare	Spell		Priest	4			Discover a friendly minion that died this game. Summon it. What do you mean I don't get overtime pay for this?!
Drakonid Operative	Rare	Minion	Dragon	Priest	5	5	6	Battlecry: If you're holding a Dragon, Discover a copy of a card in your opponent's deck. His job is to spy on the Goons and the Jade Lotus, but he's OBVIOUSLY a dragon so it's pretty hard work.
Lotus Agents	Rare	Minion	General		5	5	3	Battlecry: Discover a Druid, Rogue or Shaman card. Mostly, they stand around and look cool.
Servant of Kalimos	Rare	Minion	Elemental	Any	5	4	5	Battlecry: If you played an Elemental last turn, Discover an Elemental. He's doing his best, but his mom thinks that if he had just applied himself in school Kalimos would be working for HIM.
Arcane Dynamo	Rare	Minion	General	Any	6	3	4	Battlecry: Discover a spell that costs (5) more. We ran out of jars, so we started putting brains in other stuff.
Ivory Knight	Rare	Minion	General	Paladin	6	4	4	Battlecry: Discover a spell. Restore Health to your hero equal to its Cost. Do NOT call it a "horse".
Free From Amber	Rare	Spell		Priest	8			Discover a minion that costs (8) or more. Summon it. Bingo! Minion DNA!
Finders Keepers	Epic	Spell		Shaman	1			Discover a card with Overload. Overload: (1) INFINITE LOOP!
Primordial Glyph	Epic	Spell		Mage	2			Discover a spell. Reduce its Cost by (2). It's the Ancient Tol'vir symbol for "Whoops!"
Shadow Visions	Epic	Spell		Priest	2			Discover a copy of a spell in your deck. This one’s a bird. And here’s a bunny!
Chittering Tunneler	Epic	Minion	Beast	Warlock	3	3	3	Battlecry: Discover a spell. Deal damage to your hero equal to its Cost. Ear to the ground, he carefully interpreted the chittering noises: “You wanna cast a spell? I wanna cast a spell!”
Haunting Visions	Epic	Spell		Shaman	3			The next spell you cast this turn costs 3 less. Discover a spell. When you're awake at 3 AM and can't stop thinking about that time you called your teacher "mom."
Master's Call	Epic	Spell		Hunter	3			Discover a minion from your deck. Draw all three cards if they are three Beasts. "Hello? Yes, this is Huffer."
Arcane Keysmith	Epic	Minion	General	Mage	4	2	2	Battlecry: Discover a Secret. Put it into the battlefield. She sells all manner of keys: from A flat to G sharp.
A New Challenger...	Epic	Spell		Paladin	7			Discover a 6-Cost minion. Summon it with Taunt and Divine Shield. … Arrives? Approaches? TELL US ALREADY!
Gurubashi Hypemon	Epic	Minion	General	Rogue	7	5	7	Battlecry: Discover a 1/1 copy of a Battlecry minion. It costs (1). Throw your hands in the air! They cost (1).
Tortollan Primalist	Epic	Minion	General	Any	8	5	4	Battlecry: Discover a spell and cast it with random targets. I see pizza in my future.
Sir Finley Mrrgglton	Legendary	Minion	Murloc	Any	1	1	3	Battlecry: Discover a new basic Hero Power. In addition to fluent Common, he also speaks fourteen dialects of 'mrgl'.
Griftah	Legendary	Minion	General	Any	4	4	5	Battlecry: Discover two cards. Give one to your opponent at random. With Griftah in your deck, sometimes you start the game with The Coin!
Myra Rotspring	Legendary	Minion	General	Rogue	5	4	2	Battlecry: Discover a Deathrattle minion. Also gain its Deathrattle. On her first day on the job, Myra removed the smoke detectors.
The Runespear	Legendary	Weapon		Shaman	8	3	3	After your hero attacks, Discover a spell and cast it with random targets. When asked what the runes do, the tauren smith smiled: "A little of this, a little of that..."
Arch-Thief Rafaam	Legendary	Minion	General	Any	9	7	8	Battlecry: Discover a powerful Artifact. He's very good at retrieving artifacts. From other people's museums.
Showing all 49 cards

Uncollectible[edit]

This section lists all uncollectible cards that have the Discover mechanic.

For Wild format listings, see Discover/Wild format

Name / Desc	Rarity	Type	Subtype	Class	Cost	Atk	HP	Description
Draconic Lackey	None	Minion	General	Any	1	1	1	Battlecry: Discover a Dragon.
Ethereal Lackey	None	Minion	General	Any	1	1	1	Battlecry: Discover a spell.
Zarog's Crown	None	Spell		Any	3			Discover a Legendary minion. Summon two copies of it.
Transfer Student	Epic	Minion	General	Any	2	2	2	Battlecry: Discover a Dragon.
Showing all 4 cards

Wild format

This section contains information exclusive to Wild format.

Name / Desc	Rarity	Type	Subtype	Class	Cost	Atk	HP	Description
Choose Your Path	None	Spell		Warrior	1			Discover a card.
Delivery Drone	None	Hero Power		Warrior	2			Hero Power Discover a Mech. Swaps each turn.
Transfer Student	Epic	Minion	General	Any	2	2	2	Battlecry: Discover a new basic Hero Power.
Showing all 3 cards

Related cards[edit]

This section lists all cards that have Discover-related mechanics.

For Wild format listings, see Discover/Wild format

Name / Desc	Rarity	Type	Subtype	Class	Cost	Atk	HP	Description
Dwarven Archaeologist	Epic	Minion	General	Any	2	2	3	After you Discover a card, reduce its cost by (1). She's making great progress on paying off that advanced degree.
Showing the only card

Development[edit]

Discover is intended to provide a balance between random generate effects like Unstable Portal and regular card draw.^[10] While the latter can make games more predictable through accelerating the player's progress through their deck, and the former can prove too unpredictable due to the extremely large and non-class limited pool of potential cards, Discover effects are intended to add variety to games without excessively disturbing class balance, and while still allowing players some control over which card they gain.^[10]
The Discover ability was originally called "Treasure", a name which is still found in the game's strings.^[10]^[11] The original idea was pitched by Mike Donais, before design work had started on The Grand Tournament, but the developers did not start experimenting with adding it to cards until they began work on The League of Explorers.^[10]
The developers tried different places for the Discovered card to go, including the top of the deck, and shuffling it into the deck at random. The former proved problematic because of shuffle into deck effects, which not only adds cards to the player's deck but also shuffle the entire undrawn deck; as a result, activating such an effect after a Discover effect would cause the chosen card to become lost in the player's deck, losing much of the value and making the mechanic less reliable. Conversely, if this didn't happen, the card drawn at the start of the next turn would already be known by the player. This removed the surprise at the drawing of an unknown card, and in tough situations often led to a feeling of powerlessness, since the player would know in advance that they were not going to draw next turn a card that was capable of dealing with the state of the board; or otherwise know in advance that they would draw the card they needed, thus taking "the drama and excitement" out of the game. The idea of shuffling the chosen card into the deck was likewise discarded due to the likelihood of the match ending before the card was drawn, thus making the effect feel unimportant and unreliable.^[10] In addition, adding the card to the top of the player's deck was an a further innovation on top of the Discover effect itself, and the designers felt it wiser "not try to do too many things all at once in a new mechanic".^[10]
In terms of card balance, through playtesting the designers found that Discover was in most cases fairly similar in value to a card draw effect. This allowed them to use the established weighting of card draw effects to guide them in choosing stats for Discover minions.^[10]
One of the last decisions made during the development of Discover was to restrict the effect to neutral and class cards.^[10] Prior to this, Discover effects were able to generate any card. With a far larger card pool to choose from, this made it much harder for players to predict which card an opponent's Discover effect had provided, and making the effect almost impossible to play around.^[10] The game-wide card pool also produced too much "class bleed", with other classes gaining access to the cards of other classes on too frequent a basis, weakening class uniqueness.^[10]
The final tweak to the ability was to increase the likelihood of class cards appearing, eventually set to four times the normal chance.^[10] This was made in order to balance the far larger number of neutral cards, ensuring that class cards would be well-represented. A similar solution had already been put in place for Arena.^[10] Note that after Patch 15.2.0.33717, cards that Discover from a random pool no longer apply this class bonus.
After exploring the ability with The League of Explorers, the developers began experimenting with ways to feature Discover in a Tavern Brawl, partly because they were also working on the first round of Tavern Brawls at that time.^[10]
It was eventually decided for the Discover mechanic to debut through the Captain Blackheart's Treasure Tavern Brawl in October 2015.^[12] However, technical problems prevented this, and the keyword was instead announced in November at BlizzCon 2015 with its accompanying adventure, The League of Explorers.
Discover was developed "kind of" independently of The League of Explorers. Ben Brode states, "We just kind of smashed them together and it turned out that they felt very natural together."^[10] The name change from "Treasure" to "Discover" was influenced by the keyword's debut with the adventure, though.^[10]

Trivia[edit]

When the Discover mechanic was introduced, all cards with this mechanic would add the chosen card to the player's hand. This is still reflected in the tooltip that is shown when hovering the mouse over a card with this ability, even though this is no longer true in all cases.
Before the introduction of Lifesteal in Knights of the Frozen Throne and subsequent expansions, Discover was the only non-launch keyword to continue to appear on cards outside of the set it was introduced in.
Before Patch 15.2.0.33717, class cards had four times the weighting of neutral cards, meaning that they were presented as options four times more often than they otherwise would be.^[13]^[14]^[15] But because of the far larger pool of neutral cards than those of any given class, in many cases neutral cards were still more commonly presented than class cards.
- For example, during the time of The League of Explorers adventure, the probabilities when playing Jeweled Scarab as a warlock were reported as a 10% chance for a class minion, 20% chance for a class spell and 70% chance for a neutral minion.^[16] This roughly matched the number of each type of card available: 3 warlock minions, 4 warlock spells, and 62 neutral minions (taking into account the 4x modifier for class cards). However, the probabilities for a mage playing Jeweled Scarab were reported as closer to 50/50 between class and neutral cards.^[17] Again, this matched the number of cards available: 16 mage cards and 62 neutral cards.

Gallery[edit]

Discovering a new Hero Power

Patch changes[edit]

Server-side patch (2020-08-13):
- Discover cards can no longer Discover themselves randomly.
- Cards that 'generate a random card' can no longer generate themselves.

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.

For more info and examples, see Game Mechanics Updates.

Patch 15.2.0.33717 (2019-09-10): Cards that Discover from a random pool no longer apply a class bonus.

As Discover pools have gotten more specific, some are too narrow and repetitive. This change will increase the variety of cards from random Discover pools.