Display the Seed entry prompt at the "Character Select" menu. Note: In the PC version, press [Tab]. Enter one of the following seed codes to activate the corresponding cheat function. Entering a seed code will prevent achievements and trophies from being earned. Additionally some codes may delete your saved game file.

Effect	Seed Code
All enemies have permanently feared	FEAR M1NT
All floors have the basement room tile set	BASE MENT
All items except troll bombs mimic Issac's movement	KEEP AWAY
CRT display	B00B T00B
Can destroy rocks	NFB8 3WSG
Character and tears turn black	PTCH BLCK
Character leaves fecal trail	BRWN SNKE
Character only visible as brown shadow	CAM0 K1DD
Character takes double damage	HARD HARD
Concussive enemies that move randomly	C0NF ETT1
Doors open immediately, tears are harmless;Boss's health act as timers	PAC1 F1SM or PAC1 F1ST
Easier game	1337 HAXR
Eligible enemies become champions	CHAM P10N
Enemies become feared randomly	FRAI DN0T
Enemies fight each other	C0CK FGHT or CLST RPH0
Enemies only visible as brown shadows	CAM0 F0ES
Enemies respawn when character leaves room;new items do not drop	C0ME BACK
Grey character	KAPP A
Invisible character except for surrounding light effect	1MN0 B0DY
Invisible enemies	BL1N DEYE
Jumbled in-game text	DYSL EX1C
Large pools of blood when enemies die	BL00 00DY
Load screen always displays "Are You Sure You Want Me To Die?"	1TEN DSHE or SUPA SWAG
Pill names and descriptions appear as ???	MED1 C1NE
Reversed controls	DRAW KCAB
Slow motion while character is idle; music speed altered with movement speed	SL0W 4ME2
Sound effects replaced with farts	FART SNDS
Start with 69 coins and have to purchase all items and pickups	FREE 2PAY or PAY2 PLAY
Take damage when idle	D0NT ST0P
Tarot cards are face down when collected	FACE D0WN
The lower your health, the slower the music	HART BEAT
Ticking starts every 45 seconds, after 5 seconds Isaac takes half heart of damage	THEG H0ST