Special Seeds...
	The Lost...
	Various Characters...
	Various Steam Achievements...

If you type in one of these codes as a seed, you can play a special run with unique features. Unlike normal seeds, the floor layout will be different each time. However, achievements & unlocks will be temporarily disabled.

Effect	Password
All enemies are friendly towards you. (Flies spawned by Duke of Flies die instantly, but Dingle's dingleberries do not)	CLSTRPHO
Applies a filter that makes the game look like it's being played through a cathode ray tube.	B00BT00B
Basement repeats infinitely.	BASEMENT
Character leaves a trail of poop behind him as he walks.	BRWNSNKE
Enemies are dazed.	C0NFETT1
Enemies are invisible (including bosses, fires, etc).	BL1NDEYE
Enemies respawn once player leaves cleared room (includes bosses). New items won't drop.	COMEBACK
Get hit by one enemy that does damage and you die. Similar to playing as The Lost.	BRTLB0NS
Isaac wears a Santa hat.	CHRSTMAS
Makes a lot more blood appear after death of the enemies.	BLOOOODY
Makes all enemies charmed permanently.	COCKFGHT
Music is slowed	ANDANTE
Music is sped up.	ALLEGR0
Turns all enemies into their champion versions (if they have one).	CHAMP10N
Turns character invisible.	CAMOK1DD
Turns enemies invisible.	CAM0F0ES
Turns pick-ups invisible.	CAMODROP

In order to unlock The Lost, you must kill yourself in very specific ways in a specific order. First you must die to a Mulliboom as Isaac in one of the Basement floors. Second you must die to a bomb blast as Magdalene in one of the Caves floors. Third you must die to Mom's Foot as Judas in one of the Depths floors. You can use seeds for the first three parts but not Azazel. Last you must die to the second stage of Satan as Azazel in Sheol. You cannot die in other ways between these specific death runs, you cannot win with any character, and you cannot use seeds. You can, however, reset between runs. If you die and quickly hold R to reset before the death screen comes up, it does not count as a death and you can continue to unlock the lost. The Lost starts with flying, and has no health, nor can he gain health through normal health pick ups. However, he can take devil deals for free.

The are multiple characters that can be unlocked in the game, each requiring you to fulfill a certain condition during a play-through. Note: You can only unlock characters in regular, random runs. Meeting the requirements in a challenge or manually inputting a random seed will not allow you to unlock characters (indicated by the no trophy icon below your stats).

Character	How to unlock
??? (The Blue Baby)	Reward for defeating Mom's Heart for the 10th time.
Azazel	Make three deals with the devil during a run.
Cain	Have 55 or more pennies at any time during a run.
Eden	Reward for defeating Mom's Heart for the first time.
Eve	Complete two consecutive floors without picking up any hearts (including Soul, Black, and Eternal Hearts)
Judas	Unlocked when you defeat Satan the first time.
Lazarus	Have 4 or more Soul and/or Black Hearts at any time during a run.
Magdalene	Have 7 or more Red Heart Containers at any time in a run
Samson	Complete two consecutive floors without taking any damage.

Achievement	How to unlock
!Platinum God!	OMG!
-0- Baby	Unlocked a new co-player baby.
???	Unlocked a new character.
???'s Only Friend	Unlocked a new item.
???'s Soul	Unlocked a new item.
A Bag of Bombs	Unlocked a new item.
A Bag of Pennies	Unlocked a new item.
A Bandage	Unlocked a new item.
A Cross	Unlocked a new item.
A Cube of Meat	Unlocked a new item.
A Fetus in a Jar	Unlocked a new item.
A Forgotten Horseman	Unlocked a new boss!
A Gamekid	Unlocked a new item.
A Halo	Unlocked a new item.
A Noose	Unlocked a new item.
A Quarter	Unlocked a new item.
A Small Rock	Unlocked a new item.
Abaddon	Unlocked a new item.
Abel	Unlocked a new item.
Angels	They are waiting.
Azazel	Unlocked a new character.
Basement Boy	Beat basement without taking damage.
Begotten Baby	Unlocked a new co-player baby.
Black Candle	Unlocked a new item.
Black Lipstick	Unlocked a new item.
Blank Card	Unlocked a new item.
Blood Bag	Unlocked a new item.
Blood Penny	Unlocked a new item.
Blood Rights	Unlocked a new item.
Bloody Lust	Unlocked a new item.
Blue Candle	Unlocked a new item.
Blue Map	Unlocked a new item.
Book of Secrets	Unlocked a new item.
Broken Ankh	Unlocked a new item.
Burnt Penny	Unlocked a new item.
Butter Bean	Unlocked a new item.
Cain	Unlocked a new character.
Cain's Eye	Unlocked a new item.
Cain's Other Eye	Unlocked a new item.
Card Against Humanity	Unlocked a new item.
Cat Got Your Tongue	Unlocked Challenge #8.
Celtic Cross	Unlocked a new item.
Chaos Card	Unlocked a new item.
Counterfeit Coin	Unlocked a new item.
Credit Card	Unlocked a new item.
Crow Baby	Unlocked a new co-player baby.
Cursed!	Unlocked Challenge #10.
Curved Horn	Unlocked a new item.
Cute Baby	Unlocked a new co-player baby.
Dad's Key	Unlocked a new item.
Daemon's Tail	Unlocked a new item.
Dark Boy	Beat depths without taking damage.
Darkness Falls	Unlocked Challenge #4.
Dead Baby	Unlocked a new co-player baby.
Dead Boy	Beat Chest or Dark Room without taking damage.
Death's Touch	Unlocked a new item.
Demo Man	Unlocked Challenge #9.
Demon Baby	Unlocked a new item.
Eden	Unlocked a new character.
Epic Fetus	Unlocked a new item.
Eve	Unlocked a new character.
Eve's Bird Foot	Unlocked a new item.
Eve's Mascara	Unlocked a new item.
Everything is Terrible!!!	The game just got harder!
Experimental Treatment	Unlocked a new item.
Fate	Unlocked a new item.
Fighting Baby	Unlocked a new co-player baby.
Forget Me Now	Unlocked a new item.
Glass Baby	Unlocked a new co-player baby.
Glass Cannon	Unlocked Challenge #11.
Glitch Baby	Unlocked a new co-player baby.
Godhead	Unlocked a new item.
Golden God!	You are the best!!
Guardian Angel	Unlocked a new item.
Guillotine	Unlocked a new item.
Guppy's Hairball	Unlocked a new item.
Head of Krampus	Unlocked a new item.
Ipecac	Unlocked a new item.
Isaac's Head	Unlocked a new item.
Isaac's Heart	Unlocked a new item.
Isaac's Tears	Unlocked a new item.
It Lives!	Your future's past waits.
Judas	Unlocked a new character.
Judas' Shadow	Unlocked a new item.
Judas' Tongue	Unlocked a new item.
Krampus	Unlocked another miniboss!
Lazarus	Unlocked a new character.
Lazarus' Rags	Unlocked a new item.
Lil' Chubby	Unlocked a new item.
Little Baggy	Unlocked a new item.
Little C.H.A.D.	Unlocked a new item.
Little Gish	Unlocked a new item.
Little Steven	Unlocked a new item.
Loki's Horns	Unlocked a new item.
Lord of the Flies	You became Lord of the Flies.
Lost Baby	Unlocked a new co-player baby.
Lucky Rock	Destroy 100 rocks.
Lucky Toe	Unlocked a new item.
Magdalene	Unlocked a new character.
Maggy's Bow	Unlocked a new item.
Maggy's Faith	Unlocked a new item.
Mama's Boy	Beat womb without taking damage.
Missing No.	Unlocked a new item.
Missing Poster	Unlocked a new item.
Mom's Contact	Unlocked a new item.
Mom's Knife	Unlocked a new item.
Monstro's Tooth	Unlocked a new item.
Mr. Mega	Unlocked a new item.
Mysterious Paper	Unlocked a new item.
Mystery Sack	Unlocked a new item.
Pandora's Box	Unlocked a new item.
Purist	Unlocked Challenge #20.
Red Candle	Unlocked a new item.
Robo-Baby 2.0	Unlocked a new item.
Rubber Cement	Unlocked a new item.
Rules Card	Unlocked a new item.
Rune of Algiz	Unlocked a new item.
Rune of Ansuz	Unlocked a new item.
Rune of Berkano	Unlocked a new item.
Rune of Dagaz	Unlocked a new item.
Rune of Ehwaz	Unlocked a new item.
Rune of Hagalaz	Unlocked a new item.
Rune of Jera	Unlocked a new item.
Rune of Perthro	Unlocked a new item.
Sacrificial Dagger	Unlocked a new item.
Samson	Unlocked a new character.
Samson's Chains	Unlocked a new item.
Samson's Lock	Unlocked a new item.
Satanic Bible	Unlocked a new item.
Shadow Baby	Unlocked a new co-player baby.
SMB Super Fan	Unlocked a new item.
Solar System	Unlocked Challenge #6.
Something Cute	New boss in the caves!
Something From The Future	New boss in the basement!
Something Icky	New boss in the womb!
Something Sticky	New boss in the depths!
Spelunker Boy	Beat caves without taking damage.
Stop Watch	Unlocked a new item.
Store Credit	Unlocked a new item.
Store Upgrade lv.1	Donated 20 pennies to the shop.
Store Upgrade lv.2	Donated 100 pennies to the shop.
Store Upgrade lv.3	Donated 200 pennies to the shop.
Store Upgrade lv.4	Donated 600 pennies to the shop.
Suicide King	Unlocked Challenge #7.
Suicide King	Unlocked a new item.
Super Meat Boy	Built him out of meat cubes.
Swallowed Penny	Unlocked a new item.
Technology .5	Unlocked a new item.
The Body	Unlocked a new item.
The Book of Revelations	Unlocked a new item.
The Book of Sin	Unlocked a new item.
The Catacombs	Alt stage to the caves.
The Cellar	Alt stage to the basement.
The D100	Unlocked a new item.
The D20	Unlocked a new item.
The D4	Unlocked a new item.
The D6	Isaac now holds the D6!
The Family Man	Unlocked Challenge #19.
The Harbingers	The horsemen are loose.
The Left Hand	Unlocked a new item.
The Lost	Unlocked a new character.
The Mind	Unlocked a new item.
The Nail	Unlocked a new item.
The Necronomicon	Unlocked a new item.
The Necropolis	Alt stage to the depths.
The Negative	Unlocked a new item.
The Parasite	Unlocked a new item.
The Polaroid	Unlocked a new item.
The Razor	Unlocked a new item.
The Real Platinum God	111% now stop playing!
The Scissors	Unlocked a new item.
The Soul	Unlocked a new item.
The Tank	Unlocked Challenge #5.
The Womb	Chapter 4 - The Womb unlocked.
There's Options	Unlocked a new item.
Undefined	Unlocked a new item.
Wire Coat Hanger	Unlocked a new item.
Wrapped Baby	Unlocked a new co-player baby.