Tips for How Many of Each Card to Choose:

4 copies – You want to draw the card as often and as early as possible. The card is essential for the deck to work as it’s supposed to, and you don’t mind drawing multiples, even in your opening hand. You might even be happy to do so. It’s rare to play legends as 4-ofs, but you can make exceptions for cards that are extremely powerful and/or removal magnets. Example: Heart of Kiran in Mardu Vehicles or Karn Liberated in Modern Tron.

3 copies – You want to see the card at some point in the midgame, but you prefer not to draw multiples. A second copy is not necessarily dead, but it’s much less valuable than the first. Most commonly, this is because the card is expensive to cast, a situational answer, and/or a non-essential legendary. Example: Kari Zev, Skyship Raider in Mono-Red Aggro or Teferi, Hero of Dominaria in U/W Control.

2 copies – You’re not excited to see the card in your opening hand, and it’s not vital to your strategy. Often, the card is not much better than the alternatives, worthless in multiples, and/or crazy expensive to cast. Example: Josu Vess, Lich Knight in Mono-Black Control or Ugin, the Spirit Dragon in Modern Tron.

1 copy – You don’t want to draw the card naturally, but you want to have access to one in your deck. Most commonly, this is because it’s a kill condition for strategies that see their entire deck, because you hope to mislead your opponent into thinking you’re playing more copies than you actually are, or because it’s a tutor target in a toolbox-style deck. For example: Elesh Norn, Grand Cenobite in Gifts Ungiven decks or Shalai, Voice of Plenty in Chord of Calling decks.