Hard mode

Hard mode changes the gameplay compared to Normal in some ways to make it more difficult. When playing in hard mode, a small red pentagram () appears on the HUD, below the consumables.

• Rooms contain more advanced enemies and in a higher number.
• Causes champions to spawn more often; however, they award fewer pickups.
• You are 65% less likely to receive hearts after completing a room.
• Only champion bosses can drop red hearts; normal bosses will not.
• You are more likely to be cursed on each floor.
• You are more likely to receive a harder version of a floor (e.g. Necropolis or Dank Depths instead of The Depths).

Unlocks for Hard Mode

Character	Mom's Heart	All Completion Marks
Isaac	Lost BabyDefeat Mom's Heart on hard mode as Isaac	Buddy BabyEarn all hard mode completion marks as Isaac
Magdalene	Cute BabyDefeat Mom's Heart on hard mode as Magdalene	Colorful BabyEarn all hard mode completion marks as Magdalene
Cain	Glass BabyDefeat Mom's Heart on hard mode as Cain	Picky BabyEarn all hard mode completion marks as Cain
Judas	Shadow BabyDefeat Mom's Heart on hard mode as Judas	Belial BabyEarn all hard mode completion marks as Judas
???	Dead BabyDefeat Mom's Heart on hard mode as ???	Hive BabyEarn all hard mode completion marks as ???
Eve	Crow BabyDefeat Mom's Heart on hard mode as Eve	Whore BabyEarn all hard mode completion marks as Eve
Samson	Fighting BabyDefeat Mom's Heart on hard mode as Samson	Revenge BabyEarn all hard mode completion marks as Samson
Azazel	Begotten Baby Defeat Mom's Heart on hard mode as Lazarus Defeat Mom's Heart on hard mode as Azazel	Sucky BabyEarn all hard mode completion marks as Azazel
Lazarus	Wrapped Baby Defeat Mom's Heart on hard mode as Azazel Defeat Mom's Heart on hard mode as Lazarus	Dripping BabyEarn all hard mode completion marks as Lazarus
Eden	Glitch BabyDefeat Mom's Heart on hard mode as Eden	Cracked BabyEarn all hard mode completion marks as Eden
The Lost	-0- BabyDefeat Mom's Heart on hard mode as The Lost	Godhead Beat Mom's Heart, Isaac, Satan, ???, and The Lamb and complete the Boss Rush on hard mode as The Lost Earn all 9 Completion Marks on hard mode as The Lost
Lilith	Goat Head BabyDefeat Mom's Heart on hard mode as Lilith	Dark BabyEarn all hard mode completion marks as Lilith
Keeper	Super Greed BabyDefeat Mom's Heart on hard mode as Keeper	Sale BabyEarn all hard mode completion marks as Keeper
Apollyon	SmelterDefeat Mom's Heart or It Lives! on hard mode as Apollyon	Apollyon BabyEarn all Hard Mode Completion Marks as Apollyon
The Forgotten	MarrowDefeat Mom's Heart or It Lives! on hard mode as The Forgotten	Bone BabyEarn all Hard Mode Completion Marks as The Forgotten

Trivia

• Prior to update 1.03, the reduced drop-rate affected all Pickups (not just Red Hearts).
• GodheadIncreases damage and range while reducing tears and shot speed. Grants homing tears and tears gain a damaging halo.'s unlock requirements were extended in the Afterbirth DLC (and further extended in the Afterbirth+ DLC) due to the addition of more completion marks, but it can still be unlocked in the base game using the same method.