In MTG Arena, new players receive free cards and decks as part of the New Player Experience (NPE) to kick start their collection. There are five mono-colored decks given after completing the tutorial (the Color Challenge), that are designed not to change or rotate. Unique cards here are called the Arena Base Set, and are legal in digital formats such as Alchemy and Historic.
After that, players can participate in the Starter Deck Duel event to choose one of the ten dual-colored decks, each with some Rares and Mythic Rares, and if you win with the chosen deck it is added to your collection. Players can also skip the NPE under Options > Account and receive all the decks right away.
In terms of implications on player card collections, it is advised to avoid crafting or opening additional cards, until you receive all the cards in these decks. This is because once you obtain the cards through another method (e.g. opening packs), you do not receive additional copies if you get the deck after. Here’s a reminder that you can also receive a lot of free packs and cosmetics from promotional codes!
Existing players should at least check what cards you get in these free starter decks before crafting certain rares or mythics. Every two years, Standard undergoes Rotation and the ten dual-color Starter Decks are updated as part of the Renewal Rewards and granted to all players closer to the date.
Mono-Color Starter Decks 2024
Dual-Color Starter Decks 2024