Theme decks are unique pre-built decks of 10 preset cards that can’t be used until the player collects all cards in the deck.
Once all cards in a Theme deck are obtained, the Theme Deck is unlocked and acts like a Deck slot with preset cards which can't be changed.

Each theme deck is built to be usable in the early game, mid-game or late game, depending on the deck.

Each Planeswalker has access to three theme decks: Beginner, Expert, and Master.

Typically the Theme Decks follow the structure:



This is how the Themed Decks are shown when locked (notice that you can see how many cards you already have from each deck).



When you click on any decks, the details will open, and you can see which cards are pre-selected for each Themed Deck.

If you open the Beginner Deck (from the image above), you’ll see it’s incomplete. You can also see which cards you already own (four cards) and the ones you need to get (six cards) to be able to complete the deck.



Once you collect the 06 missing cards from the Beginner Deck, you’ll complete the deck and earn a reward.

Each themed deck completed grants you a reward:



If you have completed a Themed Deck and didn’t claim its rewards yet, a notification will show for you to do so.
Inside the menu options, a red dot will be next to the Planeswalker button. Click on it, and the Planeswalker tab will open.
The planeswalker whose deck you have completed will have a red dot in their picture. Click on it and the planeswalker’s details and decks will open.
You’ll see a red dot on the completed (and unlocked) Themed deck.



Once you click on the deck, the reward for its completion will show, and you’ll be able to claim it. Then the deck’s details will be shown and you can check that it is now completed.



Remember that the Themed Decks will be completed as you get the cards for each deck when you open booster packs.

If you still need assistance, please contact Customer Support.

Updated on 08/02/2022: Added more details and images for clarity.