New to the game? There are 5 Starter Decks in total; one for each prism. Each set has 30 cards. You can unlock them together with their corresponding Heroes in Skypass.
Heroes determine the types of cards you can wield in a match and therefore are tied to Starter decks. As you level up, you will unlock the different Heroes and their corresponding Starter decks.
There are no Starter decks for dual prism heroes since you would have already unlocked one from each of the two prisms.
The 5 Starter decks will grant a new player +150 Base cards which can be used to build custom decks so you can start playing Constructed mode right away.
Be sure to check your Skypass and claim the Heroes/Starter Decks you earned so you can start using them!