Magic Find

Magic Find is the common term for items that possess the "% Better Chance Of Getting Magic Items" (Diablo II) or "% Better Chance of Finding Magical Items" (Diablo III). It is a magical effect that increases the likelihood that a magic, rare, set, or unique item will drop. Before high magic find penalties, it will scale up the chance for an enemy to drop a magical item linearly based on their drop rate. Magic Find is added across all items for your character.

Diablo III

 * (Before Patch 1.0.4) Magic Find works different when in a party. The chance to get a magic item is averaged among all party members. So if there are 2 people in a party and one member has 100% magic find and the other has 0% you have an average of 50% to find a magic item. This makes it best if all party members have around the same magic find to avoid reducing the percentage of magic items found.
 * Before patch 2.0, each Paragon level used to increase Magic Find by 3% (up to 300% total).
 * Magic Find % has a hard cap of +300% from all sources.
 * Joining to a group multiplicatively boosts the Magic Find of all members by +10% of existing amount (minimum 10%) per player beyond the first.
 * 20% (one fifth) of the Magic Find from follower's items is applied to player.
 * As of patch 2.0, Magic Find can no longer roll on an item as a random affix. The only ways to increase this stat are pre-patch items, Fortune Shrine (+25%) or some legendary items that have either a guaranteed bonus (for example, Aughild's Peak set helmet for +11-12%) or set bonus (for example, Legacy of Nightmares set of two rings giving +15%).
 * Bonus legendary find for each slide of Torment difficulty (approximately 1.15^N, N being the number of Torment N) stacks with Magic Find multiplicatively. While in Neplalem Rift, the chance is further boosted by additional 100% (also multiplicatively).