The "Swamp" card from the Magic: The Gathering Mirrodin set is designated as an Unknown rarity card, numbered #296. It serves as a basic land card that provides black mana, essential for many deck strategies. Currently valued at $1.71, its market presence reflects its utility in gameplay rather than rarity, making it a staple for collectors and players alike. Grading data shows that basic lands like this often maintain steady demand in the secondary market.