From the wiki “Magic find is an attribute that increases a player’s chance to receive uncommon loot from dead foes. Magic find is applied when a foe dies; it does not apply to loot from chests or items randomly created in the Mystic Forge. Everytime you kill a monster you roll on a number of tables, inside these tables are different rarity categories. Magic find increases the chances you will get higher categories. For example if there is a 1 in 10 category, and you have 200% magic find you will have 3/10 chances to get that category. This improves not just the rarity of the items you get but can also improve your chances at getting trophies and rare crafting materials like lodestones.”
