Discover

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.
 * Boom Squad offers the player exactly one Lackey, one Mech, and one Dragon.

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 offers Hero Powers from any class to replace the player's current Hero Power.
 * Cleric of Scales allows the player to draw a spell 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.

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

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

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

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

Development

 * Discover is intended to provide a balance between random generate effects like Unstable Portal and regular card draw. 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.
 * The Discover ability was originally called "Treasure", a name which is still found in the game's strings. 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.
 * 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. 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".
 * 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.
 * One of the last decisions made during the development of Discover was to restrict the effect to neutral and class cards. 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. 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.
 * The final tweak to the ability was to increase the likelihood of class cards appearing, eventually set to four times the normal chance. 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. 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.
 * It was eventually decided for the Discover mechanic to debut through the Captain Blackheart's Treasure Tavern Brawl in October 2015. However, technical problems prevented this, and the keyword was instead announced in November at 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." The name change from "Treasure" to "Discover" was influenced by the keyword's debut with the adventure, though.

Trivia

 * 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.  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. 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. Again, this matched the number of cards available: 16 mage cards and 62 neutral cards.

Patch changes

 * Scholomance Academy logo.png 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.


 * 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.


 * Added.