56 Leaf Clover

It gives Elite mobs a 4% chance to drop items. Any more picked up after the first one grants an additional 1.5% chance. This item caps at a 100% chance at 67 pickups. There can only be 1 item dropped by, i.e. 1 item for elite monsters, 2 items for elite bosses(1 for boss, 1 for clover).

Note: If a Scavenger is present on the final level and the player activates the Providence fight, the 56 Leaf Clover will be unlocked without having to actually kill the Scavenger.

Item Synergies

 * Works well with the Artifact of Honor, as all enemies are elite (Be careful though, the game crashes if too many item boxes are opened at the same time)

Trivia

 * The Clover is called "54 Leaf Clover" in the achievements screen.
 * It is a reference to the Guinness world record for the most leaves on a single clover stem. A 4-leaf clover is considered to bring good luck, so 56 leaves must be even luckier.
 * Risk of Rain 2 has a 57 Leaf Clover, which is in reference to this clover. Its effect may be vastly different, but it is still described to hold great luck.

Bugs

 * As stated above in the article, this item actually gives a 1% chance of getting an item (additive stacking), not 4%.