Luck

Luck Stat Icon.png 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:

Character	Luck
Keeper Dead Tainted Lazarus Tainted Keeper	-2
Lazarus Esau	-1
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 Lucky Foot, 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.
- For Jacob and Esau, 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.
- Certain tear effect chances scale linearly with luck, while others scale exponentially with luck, meaning that it can take a lot of luck to notice a significant increase in activation rates.
- Tear items affected by Luck are:
  - Abaddon (Tears cause fear) - 100% at 85 Luck
  - Apple! (Razor tears) - 100% at 14 Luck
  - Ball of Tar (Tears slow enemies) - 100% at 18 Luck
  - Bird's Eye (Fire produced along with tear) - 50% at 10 Luck
  - The Common Cold (Poison tears) - 100% at 12 Luck
  - Dark Matter (Tears cause fear) - 100% at 20 Luck
  - Euthanasia (Needle tears) - 25% at 15 Luck
  - Evil Eye (Eye tears) - Slight increase with high Luck
  - Fire Mind (Chance that tears explode) - 100% at 13 Luck
  - Ghost Pepper (Fire produced along with tear) - 50% at 10 Luck
  - Holy Light (Tears inflict Crack the Sky effect) - Maximizes at 50% at 9 Luck
  - Iron Bar (Tears confuse enemies) - 100% at 27 Luck
  - Lodestone (Tears cause enemy to become magnetized) - 100% at 5 Luck
  - Ocular Rift (Tears create rifts) - Slight increase with high Luck
  - Little Horn (Instant death tears) - Maximizes at 20% with 15 Luck
  - Loki's Horns (4-way tears) - 100% at 15 Luck
  - Mom's Contacts (Tears petrify enemies) - Maximizes at 50% with less than 20 Luck
  - Mom's Eye (Forwards and backwards tears) - 100% at 5 Luck
  - Mom's Eyeshadow (Tears charm enemies) - 100% at 27 Luck
  - Mom's Perfume (Tears cause fear) - 100% at 85 Luck
  - Mom's Wig (Spawn blue spiders while shooting) - 100% at 10 Luck
  - Parasitoid (Egg tears) - Maximizes at 50% with around 20 Luck
  - Spider Bite (Tears slow enemies) - 100% at 15 Luck
  - Tough Love (Teeth instead of tears) - 100% at 9 Luck
- Trinkets affected by Luck are:
  - Black Tooth (Poisonous double damage tear) - 100% at 32 Luck
  - Cain's Eye ( The Compass effect) - 100% at 3 Luck
  - Cartridge ( The Gamekid effect when hit) - 100% at 38 Luck
  - Eve's Bird Foot (Spawn a dead bird on killing an enemy) - 100% at 8 Luck
  - Isaac's Fork (Heal half a heart on clearing a room) - 100% at 18 Luck
  - Jawbreaker (Chance for tooth shot dealing x3.2 damage) - 100% at 9 Luck
  - A Missing Page ( The Necronomicon effect) - Maximizes at 50% with 50-60 Luck
  - Old Capacitor - Maximizes at 33% with 5 Luck
  - Ouroboros Worm (Chance to shoot homing tears) - 100% at 5 Luck
  - Pinky Eye (Poison tears) - 100% at 18 Luck
  - Push Pin (Spectral + Piercing tears) - 100% at 18 Luck
  - Red Patch (+1.8 Damage Up on taking damage) - 100% at 8 Luck
  - Samson's Lock (Chance for +0.5 Damage Up on killing an enemy) - 100% at 10 Luck

- Other items affected by Luck include:
  - Broken Modem: Higher luck increases the rate of freezing enemies and their shots.
  - Celtic Cross: The Celtic Cross grants its invulnerability more often with higher Luck, topping out at 100% at 27 Luck.
  - Gimpy: The Soul Heart/Black Heart drop chance upon taking damage increases with higher Luck, topping out at 50% at 22 Luck.
  - Midas' Touch: Poops generated by Isaac's actions have a chance to turn into Golden Poop, starting at 10% with 0 Luck up to 100% at 18 Luck.
  - Mystery Gift: Higher luck results in a lower chance of getting The Poop or A Lump of Coal.
  - Old Bandage: The Red Heart drop chance when you take a hit increases with higher Luck, topping out at 50% at 29 Luck.
  - Virgo: The shield activation chance increases with Luck, topping out at 100% at 10 Luck.

However, Luck doesn't affect:

Fortune Telling Machine, Portable Slot, Shell Game, Slot Machine: Their chance of giving a consumable don't increase with Luck. Only Lucky Foot increases the winning chances with these machines.
The activation chance of: Fanny Pack, Dry Baby, The Mulligan, Broken Watch, Infamy, Tech.5, Guppy's Collar, Undefined (for I AM ERROR or Black Market teleports), We Need to Go Deeper! (Crawl Spaces | Only on specific floor tiles), Pandora's Box (as its effects are predetermined depending on which floor it's used on), and Missing Page 2.
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[]

Activated Items[]

Name	ID	Icon	Quote	Description	Quality
Mom's Box	5.100.439		What's inside?	Increases luck by 1 and doubles the effects of trinkets while held. When used, drops a random trinket on the ground.	3
Dataminer	5.100.481		109	Displaces enemy sprites for the current room, randomly increases one stat and decreases another.	0

Passive Items[]

Name	ID	Quote	Description	Quality
Latch Key	5.100.343	Luck up	Grants 1 Soul Heart and +1 luck. Spawns 2 Keys.	2
Lucky Foot	5.100.46	Luck up	+1 luck. Increases chance of winning Shell Games and Fortune Tellers (independent from the luck stat). Converts all bad pills into good pills, without identifying them.	2
Magic Scab	5.100.253	HP + luck up	Grants one full Red Heart container, +1 luck.	2
Missing No.	5.100.258	Syntax error	Randomizes all passive items and stats upon pickup and at the start of each succeeding floor.	1
Mom's Pearls	5.100.355	Range + luck up	+1.25 range, +0.5 tear height, +1 luck. Grants one Soul Heart.	2
YO LISTEN!	5.100.492	Yo listen!	+1 luck. Spawns a fairy familiar that points out Secret Rooms, Crawl Space entrances, and tinted rocks.	2
Candy Heart	5.100.671	Power of love	Gives Isaac a permanent stat boost whenever he heals with Red Heart pickups.	2
Evil Charm	5.100.632	Luck up + you feel protected	Increases luck by 2.0. Provides immunity to burn, confusion, fear, and poison.	2
Glass Eye	5.100.730	DMG + luck up	+0.75 damage, +1 luck.	3
Sausage	5.100.669	All stats up	Adds a Red Heart Container, fully heals Isaac, and gives +0.2 Speed, +0.5 Damage, +0.5 Tears, +1.5 Range, +0.2 Shot Speed, and +1.0 Luck. Increases the chance of encountering a Devil Room, Angel Room, and/or Planetarium each by 6.9%.	3
Sol	5.100.588	Radiant victory	Reveals the location of the Boss room. Upon defeating a boss, activates XIX - The Sun, fully recharges Isaac's active item, grants bonus damage and luck for the rest of the floor, and removes curses.	2
Soul Locket	5.100.686	Power of faith	Gives Isaac a permanent stat boost whenever he picks up a soul heart.	2

Trinkets[]

Name	ID	Icon	Quote	Description
Lucky Toe	5.350.42		Luck up!	+1 Luck. Adds a chance to drop an extra pickup when opening a Chest, destroying a machine, or blowing up a tinted rock.
Perfection	5.350.145		Luck way up. Don't lose it!	+10 Luck. If Isaac takes damage, the trinket is destroyed and its effect is removed.

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.