Luck

[мусоровоз говнищ]

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 (except in Repentance) 66%/(in Repentance) 33% of heart-type drops, replacing them with nothing.
(in Repentance) If there is more than one playable character on screen (Jacob and Esau, Co-op, using the item (in Repentance)Strawman, 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:
Abaddon (Tears cause fear) - 100% at 85 Luck
(in Afterbirth † and Repentance)Apple! (Razor tears) - 100% at 14 Luck
Ball of Tar (Tears slow enemies) - 100% at 18 Luck
(in Repentance)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
(in Repentance)Dr. Fetus has luck based effects with certain bomb items
Brimstone Bombs (Bombs create Brimstone beams) - 100% at 29.67 Luck
Butt Bombs (Bombs damage and confuse every enemy) - 100% at 27 Luck
Hot Bombs (Bombs damage on contact and leave a fire) - 100% at 12.34 Luck
Ghost Bombs (Bombs spawn ghosts) - 100% at 8.25 Luck
Sad Bombs (Bombs burst into tears) - 100% at 29.67 Luck
Scatter Bombs (Bombs explode into smaller bombs) - 100% at 8.25 Luck
(in Afterbirth † and Repentance)Euthanasia (Needle tears) - (except in Repentance) 100% at 14.5 Luck / (in Repentance) 25% at 13 Luck
(except in Rebirth)Evil Eye (Eye tears) - 10% at 20 Luck
Fire Mind (Chance that tears explode) - 100% at 13 Luck
(in Repentance)Ghost Pepper (Fire produced along with tear) - 50% at 10 Luck
(except in Rebirth)Holy Light (Tears inflict Crack the Sky effect) - 50% at 8.89 Luck
Iron Bar (Tears confuse enemies) - 100% at 26.95 Luck
(in Repentance)Knockout Drops (Tears knock back enemies significantly) - 100% at 8.01 Luck
(in Afterbirth † and Repentance)Little Horn (Instant death tears) - 20% at 15 Luck
(in Repentance)Lodestone (Tears cause enemy to become magnetized) - 100% at 5 Luck
Loki's Horns (4-way tears) - (except in Repentance) 100% at 7 Luck / (in Repentance) 100% at 15 Luck
(except in Rebirth) Loki's Horns + The Ludovico Technique - Maximizes at 20 Luck
Mom's Contacts (Tears petrify enemies) - 50% at 20 Luck
Mom's Eye (Forwards and backwards tears) - (except in Repentance) 100% at 2 Luck / (in Repentance) 100% at 5 Luck
(except in Rebirth) Mom's Eye + The Ludovico Technique - Maximizes at 10 Luck
Mom's Eyeshadow (Tears charm enemies) - 100% at 26.95 Luck
Mom's Perfume (Tears cause fear) - 100% at 85 Luck
Mom's Wig (Spawn blue spiders while shooting) - 100% at 9.5 Luck
(in Repentance)Ocular Rift (Tears create rifts) - 20% at 15 Luck
(in Afterbirth † and Repentance)Parasitoid (Egg tears) - 50% at 5 Luck
(in Repentance)Rotten Tomato (Tears mark enemies) - 100% at 4.01 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:
(in Afterbirth † and Repentance)Black Tooth (Poisonous double damage tear) - 100% at 32 Luck
(in Afterbirth † and Repentance)Cain's Eye (The Compass effect) - 100% at 3 Luck
Cartridge (The Gamekid effect when hit) - 100% at 38 Luck
(in Repentance)Chewed Pen (Tears slow enemies) - 100% at 18 Luck
Eve's Bird Foot (Spawn a dead bird on killing an enemy) - 100% at 7.6 Luck
(in Repentance)Ice Cube (Chance for each enemy to be frozen upon entering a room) - 100% at 40 Luck
Isaac's Fork (Heal half a heart on clearing a room) - 100% at 18 Luck
(in Repentance)Jawbreaker (Chance for tooth shot dealing x3.2 damage) - 100% at 9 Luck
(in Repentance)A Lighter (Chance for each enemy to be lit on fire upon entering a room) - 100% at 40 Luck
A Missing Page (The Necronomicon effect) - 50% at 60 Luck
(in Repentance)Old Capacitor - 33% at 4.34 Luck
(in Afterbirth † and Repentance)Ouroboros Worm (Chance to shoot homing tears) - 100% at 9 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 9.34 Luck
Other items affected by Luck include:
(in Repentance)Athame: Black brimstone circles are created more often with higher luck, up to 100% of the time at 30 Luck.
(in Afterbirth † and Repentance)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 26.67 Luck.
Gimpy: The Soul Heart drop chance upon taking damage increases with higher Luck, topping out at (except in Repentance)50% with 20 Luck / (in Repentance)100% at 46 Luck.
Midas' Touch: Poops generated by Isaac's actions have a chance to turn into Golden Poop, with the chance depending on the source.
A Card Against Humanity: 10% at 0 Luck to 100% at 18 Luck.
The Poop: (except in Repentance) 50% at 0 Luck to 100% at 5 Luck. (in Repentance) 33% at 0 Luck and 100% at 6.7 Luck.
Re-Lax: 25% at 0 Luck to 100% at 7.5 Luck.
(in Afterbirth † and Repentance)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 (except in Repentance)50% with 26.67 Luck / (in Repentance)100% at 80 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 | (in Repentance)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 (except in Rebirth) Bomb Bums aren't affected by Luck.


"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.
(except in Rebirth) Lucky Pennies increase luck by 1.
(except in Rebirth) In co-op, Green Baby will occasionally briefly increase luck by 2. Dark Baby will occasionally briefly increase all stats, including luck.

thanks for awards

[aywee]

i ain't reading all that
i'm happy for u tho
or sorry that happened

[Honorable_D]

Unless playing Lost or T Lost and getting (and keeping) Perfection my Luck stat very rarely goes above 3 or so.

One time I had Placebo with a Luck Up pill and ended up with 15 Luck, though.