Duels

Duels is a game mode where players face off against other players, attempting to claim 12 victories before they suffer 3 losses, similar to Arena. However, instead of drafting a deck, players are offered a choice between 4 of Hearthstone ' s 10 classes, then one of three of that class's Hero Powers, followed by one of six of that class's Signature Treasures. Players then must build a 16-card deck, using 15 cards from their collection, and the treasure they selected.

At the end of each round, whether it was a win or a loss, the player gains 5 higher maximum health and chooses three cards to add to their deck from three different choices, similar to Dungeon Run and other single-player missions. Occasionally, the player can also pick a Passive or active treasure to add to their deck.

Entry fee
Duels offers two methods of play with separate matchmaking pools: Casual and Heroic.
 * Casual runs are completely free.
 * A Heroic run costs 150 gold or a Tavern Ticket. However, Heroic runs feature success-based rewards identical to Arena rewards, including gold, arcane dust, cards, golden cards, and card packs from the latest expansion.
 * Since Patch 18.6 Arena Ticket is renamed to Tavern Ticket, which means if the player is sitting on unspent tickets, those tickets can be used in both Arena and Duels.

Selection
After starting a Duels run, the player gets to choose the following: Then, the player builds a starter deck, which
 * One of four randomly-offered heroes (classes)
 * One of six Signature Treasures of the chosen class
 * Some Signature Treasures can only be unlocked after the player completes their specific goals.
 * One of three Hero Powers of the chosen class
 * Some Hero Powers can only be unlocked after the player completes their specific goals.
 * Includes the chosen Signature Treasures and 15 unique (no duplicates) cards, from their own collection
 * Includes cards available from a certain number of sets, depending on the season
 * Does not include card in the ban list.

For more details about available selections and ban list in the current season, see.

After round
Similar to Dungeon Run and similar modes, regardless of winning or losing, after a round is finished, the player gets the opportunity to add new cards to their current deck, by:
 * Choosing one of three Passive treasures (after rounds 1 and 3).
 * Choosing one of three active treasures (after rounds 2, 4, 5, 7, 9, 11, 13).
 * Choosing one of three loot buckets, each consisting of three cards or none.

For more details about available treasures in the current season, see.

Group Learning
Group Learning (smart bucket, or auto-generated bucket) is a special loot bucket. Unlike most loot buckets which have a predetermined card pool, Group Learning has their card pool generated from gameplay data, and it is always in the middle of offering screen.

Group Learning is determined by three factors:
 * Functionality
 * How were cards played in each game?. In simple words, if you see two cards were played by players repeatedly, it’s a good indicator that there is some synergy between them.
 * Which stage of the game and what turns were these cards played?. Cards played in close turns and turns far apart usually indicate different things. The previous pair usually shows signs of combo pieces, and the latter shows cards used as earlier tools and late-game powers.
 * What is the end-game impact (win/loss) after the card pair was played?. Win-rate information is embedded in the card pair synergy score. In general, the higher the win-rate, the bigger the score. Afterwards, the score is aggregated for the bucket with some restrictions applied.
 * One of the restrictions is that the cards in the bucket needs to be different. Since each bucket contains 3 cards, {A,B,C}, the aggregation consists of 3 different card pairs: {AB, AC, BC}. Mathematically speaking, a "reversed soft-minimum" function is chosen as an aggregation method. The benefit of this over simple addition or some other aggregation methods is it helps to avoid the scenario that {AB} and {AC} has a large score value, but {BC} has a very small score value.

Gameplay
Play in Duels consists of a series of rounds between Arena players, with each player using their specially constructed deck.

During each Duel run, the player can only suffer up to 3 losses, with the number of losses so far displayed as "lost lives" on the "box" screen. Once a player has lost 3 times, or won 12 times, their run will end, along with their deck destroyed and cannot be viewed or played again.

If the player has a Heroic run, rewards befitting their success will be offered.

Players can also choose to retire their deck at any time after a run's first match. However, it should be noted that, in case you are playing a Heroic run, completing all of a deck's rounds cannot reduce the reward on offer, only improve it. Retiring a deck should therefore be a last resort used only when unwilling to play with the deck any longer.

It should also be noted that if either player is disconnected from the server during a match and fails to return through the reconnection feature, that round is counted as a loss for the disconnector.

The player plays in a Duels round like how they play in Constructed or Arena, except the fact that Duels use their own season's format of card sets and unique cards only available in Duels.

Any cards randomly generated during a match is restricted to the initial card sets. This affects cards generated from any effect and ability.

Matchmaking
Similar to Arena, matchmaking for each pairing is determined by the player's win/loss record for the current run, attempting to find a player with as similar a record as possible. Other factors such as class, deck and past Duels performance do not affect matchmaking.

It is possible for a player to be matched twice against the same player over the course of a single Duels run.

Heroic rewards
Similar to Arena, after a Heroic run ends (gets 12 wins or 3 losses ), they will be given a reward chest, containing up to five prize boxes with gold, dust, cards, and card packs. The range of possible items and values able to be given in each prize box is shown in the a rewards table exactly like what Arena currently has.

Current season
Currently, Duels is at Mid-Season of Season One with the theme Wizard Duels.

Starter card sets

 * (NEW) Forged in the Barrens
 * (NEW) Core
 * Madness at the Darkmoon Faire
 * Scholomance Academy
 * (NEW) Journey to Un'Goro
 * One Night in Karazhan


 * Whispers of the Old Gods
 * Curse of Naxxramas
 * Legacy

Classes
This section lists all current heroes, Hero Powers and Signature Treasures of each class. For more information about strategies, see indiviual pages.

For a list of each class' loot buckets, see individual Hero pages. For example: Star Student Stelina (Duels hero).

Demon Hunter

 * Hero and Hero Powers


 * Signature Treasures

Druid

 * Hero and Hero Powers


 * Signature Treasures

Hunter

 * Hero and Hero Powers


 * Signature Treasures

Mage

 * Hero and Hero Powers


 * Signature Treasures

Paladin

 * Hero and Hero Powers


 * Signature Treasures

Priest

 * Hero and Hero Powers


 * Signature Treasures

Rogue

 * Hero and Hero Powers


 * Signature Treasures

Shaman

 * Hero and Hero Powers


 * Signature Treasures

Warlock

 * Hero and Hero Powers


 * Signature Treasures

Warrior

 * Hero and Hero Powers


 * Signature Treasures

Passive treasures
This lists all Passive treasures that can be drafted after round 1.
 * Pool 1

This lists all Passive treasures that can be drafted after round 3.
 * Pool 2

This lists all Passive treasures that can be drafted after round 3, but have only 1% chance to be offered.
 * Pool 2 Ultra Rare

Active treasures
This lists all active treasures that can be drafted after rounds 2, 5, 7, 9, 11 and 13.
 * Pool 1

This lists all active treasures that can be drafted after round 4.
 * Pool 2

This lists all active treasures that can be drafted after round 4, but have only 1% chance to be offered.
 * Pool 2 Ultra Rare

Banned cards

 * Banned from Deckbuilding


 * Banned from card buckets


 * Removed treasures

Seasons
The Hearthstone team will also be adding new Hero Powers and treasures in a mid-season update early next year, and plan to reset Duels ratings at that time as well. At the end of each season, new heroes will be added, and some treasures will rotate out to make room for new ones.

Each season also has a theme tied to it. For example, Early Access and Season One's theme is Wizard Duels, which brings several familiar professors and luminaries from Scholomance Academy.

The following table lists all past seasons of Duels in Hearthstone history.

History
Duels was announced October 22, 2020 during the Hearthstone Fall Reveal Stream and the trailer. Afterwards, Duels was immediately launched into season Early Access as a part of Patch 18.6, available to players who either:
 * Pre-purchased Madness at the Darkmoon Faire Bundle or Mega Bundles.
 * Received Twitch Drop which contained Early Access to Duels.

Duels was set officially launch on November 17, with the transition from Early Access to Season One.

Card changes
Card changes are the alteration of cards from their previous designs. Hearthstone's designers prefer to avoid changing cards, but when the need arises, card changes will be implemented within patches.

Like collectible and Battlegrounds cards, Duels cards have been design-changed intentionally through the patches.

Patch changes

 * Fixed a Duels bug where the win counter could show -1.
 * Fixed a Duels bug where duplicate card buckets could appear.
 * Fixed a Duels bug where your deck would not appear on the end of run screen.
 * Added.
 * Added.