Common cards in Card Crush

Use the Common tier to compare the cards you already have for an open slot. A Common card’s affinity can change its Battle Score against a particular opponent. Card Crush game rules

Can a Common card win against a rarer card?

Yes. Rarity is not a term in the Battle Score formula. Suppose a Common card at Power 5 receives a +3 affinity bonus against a Rare opponent at Power 7 with no bonus. The Common card wins 8-7. Those numbers illustrate scoring, not the stats of a listed card.

Start with the slot an existing Common card can fill. If it already wins that matchup, the tier alone is no reason to replace it. How card stats work · Compare two cards

Buying a box to look for another Common? Check what the box guarantees before comparing it with a card you already own.