"Scars of Mirrodin" is a Magic: The Gathering expansion set released in 2010. It is the first set in the Mirrodin block and features a storyline centered around the conflict between the Mirran and Phyrexian factions. The set introduces new mechanics, such as Metalcraft, which rewards players for controlling three or more artifacts. The expansion includes 249 cards and is notable for its focus on artifacts, reflecting the metallic theme of the Mirrodin plane. It also features a variety of new creatures, spells, and abilities, enhancing gameplay and strategy for players.