Luck

**Luck** affects a variety of chance-based effects and is represented by a 3-leaf clover.

The large majority of characters have a base Luck of 0. The following characters are exceptions:

  Jacob | 1

* Eden and  Tainted Eden: varies between -1 and 1, inclusive (including decimal values).
* Cain's base Luck is technically 0, but he starts with , increasing his luck to 1.

## Effects of Luck

Luck influences many different elements:

* **Room drops:** For calculating room drops, luck is capped between 0 and 10, with higher luck not only resulting in higher amounts of drops but also higher quality drops such as chests.
	+ Room drop rates are otherwise identical in Normal and Hard game modes, but Hard mode removes  66%/ 33% of heart-type drops, replacing them with nothing.
	+ If there is more than one playable character on screen (Jacob and Esau, Co-op, using the item , etc.) the room drop rate depends on the total luck the 2 characters have.
* **Tear effect chance:** The chance of shooting tears with status effects becomes more likely as Luck goes up. This scales up to 100% chance per tear in most cases with enough Luck.
	+ Most of the status inflicting effects require high Luck to activate on every tear.
		- Since these effects persist on the enemies for a set amount of time regardless of the Tears stat, a fast rate of fire is often enough to affect an enemy indefinitely.
	+ Most tear effect chances scale exponentially with luck, while a few others scale linearly with luck, meaning that it can take a lot of luck to notice a significant increase in activation rates in most cases.
	+ However not all effects scale up to 100%, and some items have the rates capped at a lower percentage. If the maximum activation rate is not 100% for an item, the true maximum rate will be listed instead.
	+ Tear items affected by Luck are:
		- (Tears cause fear) - 100% at 85 Luck
		- (Razor tears) - 100% at 14 Luck
		- (Tears slow enemies) - 100% at 18 Luck
		- (Fire produced along with tear) - 50% at 10 Luck
		- (Poison tears) - 100% at 12 Luck
		- (Tears cause fear) - 100% at 20 Luck
		- has luck based effects with certain bomb items
			* (Bombs create  beams) - 100% at 29.67 Luck
			* (Bombs damage and confuse every enemy) - 100% at 27 Luck
			* (Bombs damage on contact and leave a fire) - 100% at 12.34 Luck
			* (Bombs spawn ghosts) - 100% at 8.25 Luck
			* (Bombs burst into tears) - 100% at 29.67 Luck
			* (Bombs explode into smaller bombs) - 100% at 8.25 Luck
		- (Needle tears) -  100% at 14.5 Luck /  25% at 13 Luck
		- (Eye tears) - 10% at 20 Luck
		- (Chance that tears explode) - 100% at 13 Luck
		- (Fire produced along with tear) - 50% at 10 Luck
		- (Tears inflict  effect) - 50% at 8.89 Luck
		- (Tears confuse enemies) - 100% at 26.95 Luck
		- (Tears knock back enemies significantly) - 100% at 8.01 Luck
		- (Instant death tears) - 20% at 15 Luck
		- (Tears cause enemy to become magnetized) - 100% at 5 Luck
		- (4-way tears) -  100% at 7 Luck /  100% at 15 Luck
			* **Loki's Horns** +  - Maximizes at 20 Luck
		- (Tears petrify enemies) - 50% at 20 Luck
		- (Forwards and backwards tears) -  100% at 2 Luck /  100% at 5 Luck
			* **Mom's Eye** +  - Maximizes at 10 Luck
		- (Tears charm enemies) - 100% at 26.95 Luck
		- (Tears cause fear) - 100% at 85 Luck
		- (Spawn blue spiders while shooting) - 100% at 9.5 Luck
		- (Tears create rifts) - 20% at 15 Luck
		- (Egg tears) - 50% at 5 Luck
		- (Tears mark enemies) - 100% at 4.01 Luck
		- (Tears slow enemies) - 100% at 15 Luck
		- (Teeth instead of tears) - 100% at 9 Luck
	+ Trinkets affected by Luck are:
		- (Poisonous double damage tear) - 100% at 32 Luck
		- ( effect) - 100% at 3 Luck
		- ( effect when hit) - 100% at 38 Luck
		- (Tears slow enemies) - 100% at 18 Luck
		- (Spawn a dead bird on killing an enemy) - 100% at 7.6 Luck
		- (Chance for each enemy to be frozen upon entering a room) - 100% at 40 Luck
		- (Heal half a heart on clearing a room) - 100% at 18 Luck
		- (Chance for tooth shot dealing x3.2 damage) - 100% at 9 Luck
		- (Chance for each enemy to be lit on fire upon entering a room) - 100% at 40 Luck
		- ( effect) - 50% at 60 Luck
		- - 33% at 4.34 Luck
		- (Chance to shoot homing tears) - 100% at 9 Luck
		- (Poison tears) - 100% at 18 Luck
		- (Spectral + Piercing tears) - 100% at 18 Luck
		- (+1.8 Damage Up on taking damage) - 100% at 8 Luck
		- (Chance for +0.5 Damage Up on killing an enemy) - 100% at 9.34 Luck
	+ Other items affected by Luck include:
		- : Black brimstone circles are created more often with higher luck, up to 100% of the time at 30 Luck.
		- : Higher luck increases the rate of freezing enemies and their shots.
		- : The Celtic Cross grants its invulnerability more often with higher Luck, topping out at 100% at 26.67 Luck.
		- : The Soul Heart drop chance upon taking damage increases with higher Luck, topping out at 50% with 20 Luck / 100% at 46 Luck.
		- : Poops generated by Isaac's actions have a chance to turn into Golden Poop, with the chance depending on the source.
			* : 10% at 0 Luck to 100% at 18 Luck.
			* :  50% at 0 Luck to 100% at 5 Luck.  33% at 0 Luck and 100% at 6.7 Luck.
			* Re-Lax: 25% at 0 Luck to 100% at 7.5 Luck.
		- : Higher luck results in a lower chance of getting  or .
		- : The Red Heart drop chance when you take a hit increases with higher Luck, topping out at 50% with 26.67 Luck / 100% at 80 Luck.
		- : The shield activation chance increases with Luck, topping out at 100% at 10 Luck.

However, Luck doesn't affect:

* **Fortune Telling Machine, , Shell Game, Slot Machine:** Their chance of giving a consumable don't increase with Luck. Only  increases the winning chances with these machines.
* **The activation chance of:** , , , , , , ,  (for I AM ERROR or Black Market teleports),  (Crawl Spaces | Only on specific floor tiles),  (as its effects are predetermined depending on which floor it's used on), and .
* Content from Chests, Pots, Mushrooms, Skulls, Blue Fires, Purple Fires, Devil Rooms, and Angel Rooms.
* Beggars, Devil Beggars, Key Masters, and  Bomb Bums aren't affected by Luck.

## Items that affect luck

### Trinkets

 Dim Bulb | 5.350.101
 Vibrant Bulb | 5.350.100
 Perfection | 5.350.145

### Other

* "Luck Up" pills increase luck by 1, and "Luck Down" pills decrease luck by 1.
* Putting a coin in the Donation Machine has a small chance to increase luck by 1.
* Lucky Pennies increase luck by 1.
* In co-op, Green Baby will occasionally briefly increase luck by 2. Dark Baby will occasionally briefly increase all stats, including luck.