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 pickups.

• Rooms contain more advanced enemies and in a higher number.
• Causes champions to spawn 20% of time instead of only 5%; however, they award pickups only 33% of the time.
• You are 65% less likely to receive hearts after completing a room.
• Only champion bosses can drop Red Heart containers; 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
Magdalene
Cain
Judas
???
Eve
Samson
Azazel
Lazarus
Eden
The Lost
Lilith
Keeper
Apollyon
The Forgotten

Trivia

• Before update 1.03, the reduced drop-rate affected all pickups (not just Red Hearts).
• Godhead, Smelter, and Marrow are the only items that require playing Hard mode to unlock, with every other unlock being co-op babies.
• Godhead'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.