As a digital analogue for Magic: The Gathering's collectible printed card game, Magic Duels offers similar incentives towards card collection and determining card values through rarity. The designers of Magic determine rarity through a number of different factors, but most have to do with a card's overall impact on a game in progress. As such, more powerful cards have a more exclusive rarity, and weaker cards are typically easier to collect.
Magic's rarities are represented by the color of the expansion symbol on the center-right of each card. From least to most rare, these values are common (black), uncommon (silver), rare (gold), and mythic rare (red-orange).
While printed Magic cards use rarity as a means to incentivize collection and trading, Magic Duels has no means to trade cards between players, and has only a single venue for collection--buying booster packs with earned or purchased coins. As such, Magic Duels utilizes rarity less for collection purposes and more as a means to limit gameplay options.
In most formats of printed Magic, a player's deck is allowed to contain four copies of any given card, and any number of each kind of basic land. Magic Duels, on the other hand, restricts card collections to the following:
- Four copies of each common card;
- Three copies of each uncommon card;
- Two copies of each rare card;
- And one copy of each mythic rare card.
Though this restriction may limit options, it serves to balance gameplay, and keeps any particular deck archetype from becoming too powerful, or prevents any player from becoming too reliant on having better cards.