57 Leaf Clover

Stat
 Luck

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

The Clover makes random beneficial effects more likely to occur for the holder, and as such is the counterpart to the  (which makes beneficial effects *less* likely to occur). It affects all random effects except .

If a successful proc is not achieved on a roll, it will be rolled one additional time per Clover. For example, assume the player has one item that has a 20% chance to proc a beneficial effect on-hit, and has one 57 Leaf Clover. If the player attacks, and the item does not activate, the roll will be done once more, as the player has one Clover.

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

Since items from chests are created based on the world seed, the Clover does *not* affect them.

## Math

In order to calculate proc probability with a certain number of Clovers, the following equation can be used:

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

Where:

* *p* = total item proc chance (between 0 and 1)
* *x* = the number of Clovers in the player's inventory.
* *y* = new item proc chance (between 0 and 1) with *x* amount of Clovers.

The inverse of the equation, to find the number of Clovers required to achieve a certain proc probability, is:

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

Note that this is a logarithmic equation. As such, it is impossible to achieve 100% proc chance on an effect (regardless of the number of Clovers held), unless the base chance is already 100%.

In order to calculate proc probability with a certain number of Clovers and a certain number of times a proc chance is rolled, the following equation can be used:

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

Where:

* *p* = total proc chance (between 0 and 1)
* *x* = the number of Clovers in the player's inventory.
* *t* = the amount of times a proc chance is rolled.
* *y* = new proc chance (between 0 and 1) with *x* amount of Clovers and *t* amount of times the proc chance is rolled.

This equation is useful for calculating logbook drop chances for multi-phase bosses, like  and , or more uncommon enemies, like .

## Interaction with Purity

In the game code, the number of Clovers is referred to as "Luck," with each Clover giving +1 Luck. There are no other means of acquiring positive Luck. Negative Luck is also supported, and can be obtained via the lunar item . Positive and negative Luck will cancel each other out, and thus an equal number of Clovers and Purity will equate to 0 Luck.

The game runs a proc chance `Abs(Luck)` times, where Luck is the total amount after Clovers (positive) & Purities (negative) are applied.

If the player has 7 Clovers and 5 Purity, the 5 Purity will cancel out 5 of the Clovers, resulting in a net +2 Luck. This means any given proc chance will be rolled two additional times for a *positive* outcome. If the amount of each item is switched, resulting in -2 Luck, the proc chance will be rolled two additional times for a *negative* outcome; this can also be seen as the proc chance needing to *successfully* roll three times for it to proc (once for the initial roll and two more for each negative Luck).

## Exhaustive List of Clover Effects

Luck does *not* affect chest spawns or contents, Shrine of Chance outcomes, the chance for an  to drop, or the chance for monsters to drop items with the Artifact of Sacrifice enabled.

### Survivor Effects

* Critical strike chance. Survivors have a base 1.0% critical strike chance.
* chance to  with  (50% base chance).
* chance to inflict  on hit (base chance is equal to the proc coefficient of the damage).

### Item Effects

* chance to critical hit.
* chance to stun a target.
* chance to  a target.
* chance to fire chain lightning.
* chance to attach a sticky bomb.
* chance to fire a missile.
* chance to drop an ammo pack.
* chance to drop a gold nugget.
* chance to hook enemies.
* chance to spawn a ghost.
* chance to fire magma balls.
* chance to summon a lightning bolt.
* chance to gain gold.
* chance to get a . A single Clover reduces the chance from 20% to 4%.
* chance to replace an item with a lunar item.
* chance to instantly kill.
* chance to inflict .
* chance to barrage an enemy with lightning.
* chance to inflict .

### Gameplay Effects

* Monster log drop chance.
* Elite equipment drop chance.

### Monster Effects

* If a monster acquires critical strike chance, this chance is affected by any Clovers it has. Monsters have 0% base critical strike chance.

## Lore

```
It was a massacre. The orbital probes had incinerated both the battalion and the enemy– as well as the entire plateau. There was no life left to be found - except for one lone soldier.

The soldier trudged through the scorched plains, numbly looking for any survivors.

But he found none.

The soldier tried to find water – he had only just noticed how thirsty he was, and how much his head hurt. How much his heart hurt.

But he found none.

The soldier tried to remember, why he was out on this terrible mission, and why he had to say goodbye to so many.

But he found none.

The soldier tried to find anything – anything that could justify why he was alive. Some semblance of meaning – or hope.

And he found one.

A small leaf, peeking out from a pile of ash. He gently plucked the clover out of the ground – somehow, it survived hours of orbital bombardments.

With clover in hand, the soldier began the long trek to report back to his superiors. Was this divine intervention? Was there some meaning – some reason as to why both him and this little clover survived?

Or were they just lucky?
```

## Version History

Anniversary Update
* Major Content
	+ Added New Lore Entry: 57 Leaf Clover

## Trivia

* The 57 Leaf Clover is the successor to the 56 Leaf Clover from the first *Risk of Rain*. The 56 Leaf Clover did not interact with chance effects, but instead gave a chance for Elite monsters to drop random items upon defeat.
	+ This behavior is partially carried over to *Risk of Rain 2*, as the 57 Leaf Clover affects the chance for Elite monsters to drop their Elite equipment.
* Before the Artifacts update, the unreleased code for the Artifact of Sacrifice would check for the Luck of the killer. ***This is no longer the case***.
* Before the full release of Risk of Rain 2,  and  were affected by the Luck stat, and therefore were more likely to proc when the player had a Clover. This is no longer the case, as the 1.0 update revamped both Bands.
	+ An interesting leftover of this design change is that Kjaro and Runald, the two  who spawn with the Bands in the   Abandoned Aqueduct, also both spawn with 20 stacks of 57 Leaf Clovers.
* For every frame that the Clover's effect is triggered at least once, a chime sound can be heard. This is hard to notice when striking an enemy, but it can also be triggered when the player takes damage while holding a , since the item will roll for critical strike before searching for valid targets. As such, being under the effect of the  makes this more noticeable.