Crafting consumes Arcane Dust to produce new cards, while disenchanting allows players to destroy unwanted cards, granting a quantity of Arcane Dust in exchange. Crafting is the quickest and most direct way of obtaining a specific card, provided you have sufficient Dust.
Only cards from the expert card set and non-golden versions of cards from the promotion set can be crafted and disenchanted. Other cards, such as basic and reward cards, are considered soulbound and cannot be crafted or disenchanted.
The amount of Arcane Dust required for crafting, and granted by disenchanting, is determined by the card's rarity. Golden cards also cost several times more Dust to craft, and reward several times more for disenchanting.
The combination of disenchanting and crafting allows players to convert unwanted cards into more desirable options. However, crafting any card costs between four and eight times more Dust than would be rewarded for disenchanting the same card, making the process extremely inefficient. Nonetheless this can be an extremely effective way of obtaining rarer cards, and may be a desirable option when disenchanting unwanted cards.
Since players can only have 2 of any card in a deck (and only 1 of each legendary card), disenchanting duplicate cards above this limit may be considered to have no true cost to the player. The 'mass disenchant' option allows players to automatically disenchant all duplicate cards in their collection with one click.
The only limitation to crafting lies in the required amount of Arcane Dust. While it is not possible to purchase Dust directly, all cards obtained through card packs can be disenchanted. Dust can also be obtained as a reward in the Arena. The player's current supply of Arcane Dust can be viewed in the My Collection screen.
After crafting a card, the player can choose to immediately undo the crafting, which will destroy the card and refund the full amount of Dust.
Players who already have 2 copies of a card will be unable to craft additional copies. This limit applies separately to the golden and non-golden versions of each card.
 Crafting and disenchanting
 Card changes
On occasion a patch will change a card's text or attributes. If the card is craftable, that card will then be made disenchantable for its full crafting cost, for a short period, usually two weeks. This is designed to allow players who have spent dust crafting the card to disenchant it at no cost, minimising the disruption caused by such changes to existing cards. After the adjustment period ends, the card's disenchanting reward will be restored to its usual amount.
Hearthstone's crafting system was specifically designed as an alternative to the card trading that occurs with most collectible card games. There are currently no plans to introduce card trading. As explained in official blog Hearthstone Crafting: In Dust We Trust:
- Why can’t I just trade my cards with my friends to get the cards I want?
- Many card games out there are considered “Trading Card Games,” or TCGs. While there are perks to being able to trade your cards, there are negatives to card games that support trading, even in a digital world. What do you as a player want out of trading cards? Generally, the answer is “To get the cards I want and trade away the cards I don’t!”
- What happens when the cards you have are the “wrong” cards—cards other players simply don’t want? What about when everyone wants the same cards?
- When a player opens a pack of cards in a typical TCG, they’ll generally find a fixed number of cards of various rarities. Cards of the most numerous rarity in any given pack, or “common” cards, end up having little to no value. Everyone has them and no one wants them.
- What about the rare cards? These “more valuable” cards can vary wildly from “MUST HAVE!” to “meh” and anywhere in between. In a trading system, the unimpressive rares end up being only slightly more valuable than common cards, even if they aren’t nearly as common. It’s very common for a dozen or so rare cards from any given set to contain most of the value and the rest are worth very little. People demand those high-end cards, and their value skyrockets. Can’t afford to buy all of the good rares? You better hope you’re lucky when you open your next pack.
- So in a trading-based card game, you may finally manage to get a card that is “worth” something . . . but then you want to keep that card and not trade it away. So your only option is to purchase more packs until you get something worth trading, even if you may not actually want to part with it. That’s not particularly fun. On top of that, you may even feel like you can’t play the game competitively without that specific card! It’s very frustrating, and new players are reluctant to become invested in a card game if they can’t manage to get those cards—in trade or for cash.
- Crafting allows you to get the cards you’re actually looking for without having to wait for random luck to shine your way, with no need to look for people that have a particular card you want to round out your deck.
- Hearthstone allows you to disenchant your Expert cards into Arcane Dust, and you then use the Arcane Dust to create the cards you want, instantly! It’s fast, it’s easy, and you don’t have to reference how valuable your card is on a secondary market each time to want to make a choice to trade it off or not.