57 Leaf Clover

Not to be confused with the first game's 56 Leaf Clover. The 57 Leaf Clover is an unlockable item in Risk of Rain 2. It visually resembles the first game's 56 Leaf Clover, but their effects are miles apart.

The 57 Leaf Clover adds one try per stack whenever an item tries to proc, increasing the chances to get a favorable outcome. This effect makes any items that have a chance to trigger more effective.

These include critical hits, so scoring one becomes easier.

Completing The Long Road Challenge unlocks this item.

Items and chances not affected by 57 Leaf Clover are;

 * The chance to get a reward from a Shrine of Chance.
 * The rarity of items dropped from chests and shrines.
 * Tougher Times' chance to block damage.

How to calculate chances with Clovers
The increase in chance to succeed is the chance to fail times chance to succeed;

At 20% chance of doing a critical hit without the clover, the crit chance become 20% (the base one) + 16% = 36%. The 16% is 20% of 80%, which is the base crit chance multiplied by the chance of NOT proccing the previous roll.

With multiple clovers, the formula is the same applied every time to the last percentage:

At 40% chance and 3 clovers, the final chance will be 40% + (60% * 40% = 24%) + (36% * 40% = 14.4%) + (21.6% * 40% =8.64%) = 87.04%.

At 40% chance and 4 clovers, the final chance will be same as above plus (12.96 * 40% = 5.184%) = 92.224%.