57 Leaf Clover

The 57 Leaf Clover is a item in Risk of Rain 2.

It affects all random effects other than Tougher Times. For each 57 leaf clover, if a successful proc is not achieved on a roll, it will be rolled one additional time, repeated the number of clovers the player has.

For example, a player has one item, the chance to proc it on hit is 20%, and has one 57 Leaf Clover. If the player attacks, and the item does not proc, the roll will be done once more, as the player has one clover.

Successes are measured per effect, not in a whole, so if one item roll is successful, other items that were triggered by the same proc, will continue to roll If unsuccessful.

While the mechanic may be daunting, note that since items from chests are created on world seed, clover does not affect them.

In the game code, number of clovers is referred to as "Luck" with each clover giving +1 luck, meaning Luck and # of Clovers are interchangeable. This may hint at other luck modifying mechanics in the future.

In order to calculate proc probability with clovers, the following equation can be used:

y = 1 - (1 - p)^(x + 1)

Where:

p = total item proc chance (0-1), (See Also: Item Stacking)

x = luck = the number of clovers in the player’s inventory

y = new item proc chance (0-1) with x amount of clovers

The inverse of that equation (the number of clovers required to achieve a certain proc probability) is:

x = log(1 - y) / log(1 - p) - 1

Trivia

 * The item is possibly a reference to an item in Risk of Rain, called 56 Leaf Clover.