Or worse, youre diving into the underworld prison of Tartarus
However, you can consider playing fewer than four copies of a card if: It gets worse in multiples (such as legendary creatures) It's only useful against certain matchups It's a win condition, and your control deck will have time to dig through the deck and find it You're stuck choosing between two cards which have equally strong, similar, but slightly different effects (you could play two of each) It's a slightly worse version of a card you have four copies of already, and you're including it because you want even more of that effect
Cards like Magearna and Adaman might also feature in such a build to ensure maximum synergy
Do you keep things traditional with creatures or try sacrificing noncreature permanents
As an example, the new is a lot less exciting if you already have a playset from
Plenty of decks can churn out a ton of artifacts with enough Treasure tokens to spare some for the activated ability