Reason to not disenchant extra cards

hearthstone

Crafting Mode in Hearthstone offers the option to Mass Disenchant cards. The in game screen describes the option this way:

Disenchant your extra cards to create Arcane Dust
You can't have more than 2 copies of a card in your deck (or more than 1 legendary), so you might as well disenchant the extras and turn them into Arcane Dust!

Is there a reason to hold onto these extra cards? Turning them to dust is permanent and I'm curious as to why the game is giving me the option if the only use for them is to turn them to dust.

Best Answer

When a card is changed or nerfed the disenchant reward changes to the same as the enchantment cost for a few weeks. Unless you really need the dust for crafting specific cards it's a better long term investment to wait. Best scenario you get 4X the dust if you wait.

But, if you do need specific cards for your decks it's probably not worth it to speculate on future nerfs. Card changes are not common, so this strategy is most useful if you plan on collecting every card, or every golden card.

Patch notes in the client will list such changes. It is also common for changes to be discussed by streamers or in youtube videos.

The Card Changes page on Gamepedia lists previous changes and ones about to be changed. You can subscribe to notifications for the above page to, most likely, ensure you do not miss a card change. To do so add "Card_Changes" to your watchlist after making an account, validating your email and enabling watchlist notifications in your settings. [more info]

Related Solutions

Science to Disenchanting in Hearthstone

Wojtek addressed most of your questions, but I'm just going to add details to this one question.

**Are there certain cards that are more cost effective to DE? ** There are two things that affect how much dust you get when you disenchant a card.

Card rarity
Foil/non-foil

Card rarity can be found by looking at the gem in the center of the card. Common cards have a white gem and give 5 dust when you disenchant them. The colors match the colors in World of Warcraft, with the highest being orange (legendary). Cards that are more rare will disenchant into more dust (you can see how much as Wojtek explained). Also, the cards you get as you level your hero to 10 are considered "basic" cards and don't have a rarity gem. They can't be disenchanted.

-          Normal           Gold    
-          Craft    DE      Craft   DE  
Common      40      5       400     50  
Rare        100     20      800     100  
Epic        400     100     1600    400  
Legendary   1600    400     3200    1600

If you go through the math to complete a complete set of 2 copies of every card (leaving all of the disenchanting and crafting until last), you're much more likely to need to disenchant commons and craft legendaries. source

Sometimes you can find gold (foil) versions of cards when you open packs. These cards functionally play exactly the same, but if you disenchant them (and keep the non-gold versions of the card) then you'll get more dust. On the other hand, gold versions are animated (some are QUITE nice) and a nice thing to show off.

So, to answer your question, it is generally more cost effective to disenchant the gold cards, if you don't care about the aesthetics and status of using the gold cards.

Another fact to note, if you use the "disenchant extra cards" button, it will automatically keep 2 regular and 2 gold copies of each card (for a total of 4 copies of the card). You have to manually decide which cards you want to keep and disenchant the others.

Optimal use of Hearthstone dust

An answer to your question depends on what you are trying to get out of the game.

Collecting all of the Cards!

According to the Economy of Hearthstone, in order to collect all of the cards, you should save all of your dust until you have enough to craft the cards you have missing. This article simulates optimal dust usage to calculate the total number of packs you would need on average to collect all of the cards.

Creating the Best Deck

Creating an excellent deck does not require a lot of dust or legendary cards. Trump was able to get to the Legendary rank very quickly without spending any money--you can see it here. In this series he spends his dust on several commons, a few rares, and a single epic (if I remember correctly). Most of the top players have a few legendaries in their decks, but it is not required. Decide on a deck you want to create and spend your dust getting those cards. The optimal way to spend dust to create a particular deck as fast as you can is to save up your dust until you can craft the rest of the deck.

Creating a Decent Ranked Deck

Perhaps you just want to play ranked and "rank-up" relatively quickly. The best way to do this is not to attempt to build the best deck which lots of rare cards, but to build a good deck with strong cards.

First, decide on a deck strategy that relies mostly on rares and commons. 90% or so of your deck will be made of these, so they have to work on their own with support from epics and legendaries.
Second, fill out the deck with cards that you already have that would work well in your dream deck.
Third, fill the rest of the deck with cards you already have that may not be your ideal picks, but are at least good.
Fourth, play with your not ideal deck. For optimal dust usage, you want to determine what is missing from your deck and this is best done through experience rather than theory-crafting.
Spend your dust on the cards your play experience dictates would be the best additions. If you can't afford all of your ideal cards, spend your dust getting the largest number of ideal cards you can. This is an optimal use of your dust because it gets your deck as close as possible to your ideal deck.