The Welcome Booster Core Set 2021 contains ten cards. Each Welcome Booster is exactly the same and contains a sample of legendary creatures, planeswalkers, rares, foils, showcase cards, and more. It also contains a double-sided helper card that contains tips on how to get started, find stores, and learn a lot more about the game.

Some cards appear in the Welcome Booster but do not appear in M21. They have their original expansion symbol. This printing has no effect on their legality.