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Tavern Brawl - promo.png The subject of this article is part of the
Tavern Brawl game mode.

Spellbook Duel.jpg

"Choose your spellbook carefully, champion! Pick 10 cards, and anytime you would draw a card, you instead Discover a copy of a card from your deck."

Spellbook Duel is a Tavern Brawl. It debuted on January 18, 2017.


Tavern Brawl Start End
84 January 18, 2017 January 23, 2017
122 October 11, 2017 October 16, 2017


This Tavern Brawl sees players doing battle with custom decks composed of 10 cards chosen by the player, with only 1 copy of each card allowed. At the start of the game, both players mulligan as normal, but at the start of each turn instead of drawing a card, the player will instead Discover a card from three options matching cards currently in their deck. This Discover does not remove the card from the player's deck, but instead places a copy into their hand.

Card draw effects do not operate normally during this Brawl: instead of drawing a card from the deck, the player has a copy of Peruse added to their hand. (This is technically considered card draw but does not come from the deck.) This 1 mana spell can then be used to Discover a card in the same way that players gain new cards at the start of each turn. Put into hand effects similarly generate copies of Peruse.

The combination of these special rules means the player is unable to draw cards normally, but the contents of the deck can still be altered through put into battlefield, shuffle into deck, and replace effects, as well as unique cards like Fel Reaver and Tracking. Because the deck acts as a source for each turn's Discover effect, altering the contents of the player's deck will affect which options the player is able to Discover.

Special cards[]



  • While not drawn from the player's deck, copies of Peruse generated through card draw effects like Novice Engineer, Life Tap or Coldlight Oracle do count as card draw, and will trigger draw-related effects like Chromaggus and Daring Reporter.[1]
    • Peruse cards will be generated whenever the player attempts to draw a card, even if they have no cards remaining in their deck.[1] Fatigue will not be incurred.[1]
  • The small deck size makes the mulligan especially potent. Because cards rejected during the mulligan process are not added back into the pool for possible replacements, it is possible to strongly control which cards will be included in your starting hand. For example, if the player going second rejects all four cards initially presented, they will be guaranteed to be given four of the six remaining cards, giving them a strong chance of ensuring they start each match with a certain card.
  • The Discover effect appears to select options randomly, but will never present multiple copies of the same card as options. For example, if the player's deck consists of 25 copies of Jade Idol, 1 copy of Deathwing and 1 copy of Innervate, every time the Discover process is activated the same three options will be presented: Jade Idol, Deathwing and Innervate. However, the likelihood of a card being chosen is still affected by the number of copies of that card in the player's deck. As a result, shuffling additional copies of cards into your deck (such as through Jade Idol or Weasel Tunneler) will expand the player's Discover pool and increase the chance of that card being Discovered. Shrinking the deck through Deathlord, Fel Reaver or Y'Shaarj will similarly shrink the deck and the Discover pool.
  • If the player has fewer than four cards left in their deck, the Discover process will present a number of options one smaller than the number of cards the player has left in their deck.[2] For example with three cards, the player will be given two options; with two cards, one option; and with one card, no options at all.[2] In the last case, the Discover process will not take effect at the beginning of the player's turn, and no options will be presented. Peruse will similarly cease to have any effect.[2]
  • Replacing the normal drawing of a card, the Discover effect will always take place at the start of each player's turn, even if their hand is already full. In this case the card chosen will not be added to the hand.[1]
  • "No duplicates" effects (such as Kazakus, Reno Jackson, etc) will always activate, unless multiple copies of cards have been shuffled into the deck.
  • On-draw effects such as Sea Reaver will never activate, since it is not possible to draw cards normally in this Brawl.
Specific cards
  • Fel Reaver, Keening Banshee, Skulking Geist, Hemet, Jungle Hunter, and Gnomeferatu's remove from deck effect will remove cards from the deck and therefore also the Discover pool.
  • Despite its wording, Tracking is not a true card draw effect, and will serve to remove all three cards displayed to the player from the player's deck and Discover pool. (The card chosen will be added to the hand, but still removed from the deck.)
  • Playing Mimic Pod or Thistle Tea doesn't give you extra copies of Peruse. The initial card draw effect draws a copy of Peruse, while the subsequent copy effect provides two copies of a random card from your deck. Note that this does not remove the copied card from the deck or the Discover pool.[1]
  • Gnomish Experimenter will never transform the card drawn, since it will always 'draw' Peruse.[1]

Known bugs[]

  • Playing Gnomish Experimenter will sometimes cause a a glitch resulting in a strange interaction between the Discover mechanic and the Experimenter's Battlecry, replacing a minion before the Discover screen pops up, and the Chicken card will be offered instead of the original minion that it replaced.[3]


  • Deathlord is an extremely valuable card, as not only do you get a 2/8 with Taunt, but you can also permanently remove a card from your opponent's Discover pool. With luck you can remove some of the opponent's most valuable cards early on, all but removing them from the match.
  • Gnomeferatu has a similar effect to Deathlord in the form of a Battlecry instead, and also removes other cards in addition to minions. Dropping multiple copies of this minion, alongside Deathlord and Brann Bronzebeard, can strip away most of your opponent's resources unless deck-filling cards such as Jade Idol, Gang Up and Forgotten Torch are used.
  • One method of winning is to make a Jade Golem deck. Using the Druid's Jade Idol, one can summon as many as 3 or more golems a turn and quickly obtain golems with 7/7 or more early in the game.
  • A powerful strategy is to play mage and fill your deck with Sorcerer's Apprentice, Flamewaker, Gadgetzan Auctioneer and some cheap spells. As long as you have at least one Sorcerer's Apprentice, your cards will cost 0 mana and you can indefinitely play cards thanks to Gadgetzan Auctioneer. At the same time, your Flamewaker will deal heavy damage to your opponent, and will activate from every Peruse played.
  • Similarly, Gadgetzan Auctioneer and Innervate can provide a near-infinite draw engine. Combine this with Kun the Forgotten King and Fandral Staghelm for large amounts of armor in a single turn.
  • Reno Jackson is also an extremely valuable card, since it always will activate (shuffle into deck effects aside) and you can have more than one copy of him in hand. Other "no duplicates" cards are similarly reliable: Inkmaster Solia, Kazakus, Raza the Chained and Krul the Unshackled.
  • Open the Waygate is extremely easy to complete in this Tavern Brawl because all the spells from your deck that you discover and Peruse count toward quest progression.
  • Radiant Elemental has great synergy in this Brawl, as a single Elemental on the board provides you with free copies of Peruse, Power Word: Shield, Inner Fire and so on, potentially allowing for a one-turn KO.
  • Skulking Geist can be a good tech in this Brawl as it instantly removes all copies of Peruse in your opponent's hand, and counters the aforementioned Jade Idol and Radiant Elemental strategies, albeit only in the mid to late game due to its Mana cost.


  1. 1.0 1.1 1.2 1.3 1.4 1.5 Tested by User:Taohinton, 2017-01-20
  2. 2.0 2.1 2.2 Tested by User:Taohinton, 2017-01-20, multiple times. Used Fel Reaver to reduce my deck to 1 card, then used Ancient Shade to increase the number to 2, then 3, then 4 cards, testing each time. When only 1 card remained in my deck, the Discover effect ceased to take place, or to provide me with any options. This was true at the start of several turns following reaching 1 card, and also when using Peruse; the card had no effect.
  3. tabuhli (22-01-2017). "Bizarre Gnomish Experimenter Interaction