What is Card Exchange?
Card Exchange allows you to, essentially, trade cards with the app itself.
Once you open a card that has a Card Exchange offer available, you can click the Card Exchange icon below the card to view available offers. If you have the cards necessary to complete the offer, you can click swap to get the card.
What happens to the cards that I trade in via Card Exchange?
All cards that are traded into the app via Card Exchange are removed from your account and deleted from the card database permanently. This card deletion WILL be reflected in the card count of cards that are traded in.
This also means that, hypothetically, any card can become more limited at any time.
NOTE: Card Exchange will never increase the card count of a sold out card. Once a card sells out, it can only become more limited.
Is there any cost limitation associated with Card Exchange?
No. Card Exchange is free and can be used as often as you like.
Cards can be traded up. Any base card (if you have enough duplicates and Equipment Cards) can be traded for that same base card at a higher rarity.