Binding of Isaac: Rebirth Wiki
Binding of Isaac: Rebirth Wiki

Challenge Rooms are special rooms that allow Isaac to fight enemies for extra rewards. They will only spawn on a floor if, upon entering the floor, Isaac's total health is greater than or equal to his number of heart containers. There are two kinds of challenge rooms: Normal Challenge Rooms, which appear on the first floor of a chapter or on XL floors, and Boss Challenge Rooms, which appear on the second floor of a chapter.

Normal Challenge Room[]

Challenge Room.png

Normal Challenge Rooms can only be entered if Isaac's total health (Red, Black, and Soul Hearts) is greater than or equal to his number of heart containers. Picking up its contents will cause three waves of enemies to spawn. While in chapter 4 (Womb Womb/Utero Utero), 3 waves of bosses will be spawned (usually bosses from Basement Basement/Caves Caves).

Added in Afterbirth † Each wave cleared will charge Isaac's active item by 1.

Removed in Repentance Waves[]

The enemies that spawn depend on the current chapter, and each chapter has two different possible sets of enemies:

Floor Wave 1 Wave 2 Wave 3
Basement Basement 3 Hoppers 3 Horfs 2 Clotties
5 Attack Flies 5 Pooters 4 Gapers
Cellar Cellar 3 Fatties 3 Round Worms 5 Dips
3 Gapers 3 Horfs 3 Fatties
Caves Caves 5 Chargers 4 Globins 4 Maws
5 Spitties 3 Hives 3 Hosts
Catacombs Catacombs 2 Bonies 2 Tumors 3 Wall Creeps
4 Round Worms 3 Nightcrawlers 1 Grub
Depths Depths 3 Vis 4 Leapers 4 Globins
4 Babies 5 Hoppers 4 Knights
Necropolis Necropolis 4 Knights 3 Mom's Hands 3 Fat Sacks
4 Bonies 2 Squirts 3 Nulls
Womb Womb
Utero Utero
3 Larry Jrs Chub and 3 Chargers 2 Monstros
Fistula Loki Chub
Cathedral Cathedral
Sheol Sheol
3 Larry Jrs Chub and 3 Chargers 2 Monstros
Fistula Loki Chub

Added in Repentance Waves (done in Hard Mode)[]

Floor Wave 1 Wave 2 Wave 3
Downpour Downpour 2 Preys/4 Frowning Gapers and 1 Wraith 3 Bloaties 2 Mullighouls
Dross Dross 3 Cloggies 4 Blurbs 2 Cloggies and 1 Splurt
Caves Caves 4 Chargers/3 Mulligans/3 Globins 2 Conjoined Fatties/3 Hosts/3 Maws 4 Pale Fatties/2 Tumors/4 Red Boom Flies
Catacombs Catacombs 3 Boom Flies/Buttlickers/3 Night Crawlers 1 Grub/3 Psychic Horfs/3 One Tooths 2 Walking Hosts/4 Gurgles/4 Chubbers
Flooded Caves Flooded Caves 2 Drowned Hives 2 Drowned Boom Flies and 2 Dukies 4 Blubbers and 2 Conjoined Fatties
Mines Mines 2 Quakeys and 2 Rock Spiders/2 Inks and 2 Soy Creeps 2 Gyros/2 Gyros and 1 Bouncer/2 Dannies 4 Faceless/4 Moles
Ashpit Ashpit 3 Bone Flies 3 Carrion Princesses 4 Bonies and 3 Dusty Death's Head
Depths Depths 4 Leapers/3 Lil' Haunts/3 Needles/3 Night Crawlers/3 Rotties 3 Fat Sacks/3 Needles/4 Knights 3 Wizoobs/3 Mom's Hands/3 Mr. Maws/2 Mr. Red Maws
Necropolis Necropolis 3 Double Vises/2 Swarmers and 4 Pooters/3 Rage Creeps 3 Eggys/4 Keepers/2 Mask + Hearts 3 Fat Sacks/3 Wizoobs/1 Dinga/3 Hangers
Mausoleum Mausoleum 4 Candlers/2 Whippers/2 Loose Knights 2 Snappers/2 Vis Versa 2 Lil Portals/1 Bony and 2 Cultists
Gehenna Gehenna 1 Cursed Globin 2 Vis Fatties and 2 Fetal Demons 2 Mask II + 1/2 Hearts and 1 1/2 Heart
Womb Womb 3 Leeches/2 Mega Clotties/3 Swingers Fistula/1 Chub/2 Monstros 2 Pins/Gluttony and Super Gluttony/2 Polycephalus
Utero Utero 4 Para-Bites/2 Planetoids/3 Gurglings/2 Oobs 1 C.H.A.D/4 Red Ghosts/2 Floating Hosts/3 Mask + Hearts 2 Blighted Ovums/4 Brains/2 Peeping Fatties/Gluttony and Super Gluttony
Corpse Corpse 2 Level 2 Horfs/3 Twitchies 3 Cysts/2 Level 2 Gapers 2 Leeches and 1 Adult Leech/2 Cysts and 1 Dead Meat/4 Level 2 Chargers
Cathedral Cathedral 3 Candlers 2 Wraths 2 Greeds
Sheol Sheol 4 Black Globin's Heads/3 Selfless Knights/3 Whippers 2 Bloodshot Eyes/2 Bloodshot Eyes and 1 Soul Sucker/2 Camilio Jr.s/2 Snappers 2 Greeds/1 Death/2 Dark Ones/The Pile

Boss Challenge Room[]

Boss Challenge Room Door.png

Boss Challenge Rooms can only be entered if Isaac has one or fewer hearts of health. Picking up its contents will cause two waves of bosses to spawn. Starting on Chapter 4, they use the same waves of bosses as Normal Challenge Rooms.

Added in Afterbirth † Each wave cleared will charge Isaac's active item by 1.

Removed in Repentance The Boss Challenge Room door only counts Red Hearts in determining whether Isaac is allowed to enter. Soul Hearts are ignored.
Added in Repentance Boss Challenge Rooms require one or fewer hearts total to enter, counting Soul Hearts. Boss Challenge Rooms will always contain an item from the Boss item pool.

The bosses that spawn depend on the current chapter. Alternate floors have two possible sets of bosses that could spawn:

Removed in Repentance Boss Waves[]

Floor Wave 1 Wave 2
Basement Basement Monstro Larry Jr.
Cellar Cellar Pin Gurglings
Dingle Gemini
Caves Caves Chub Peep
Catacombs Catacombs Mega Fatty Mega Maw
Fistula The Haunt
Depths Depths Loki Monstro II
Necropolis Necropolis Mega Maw The Husk
Dark One Loki

Added in Repentance Boss Waves (done in Hard Mode)[]

Floor Wave 1 Wave 2
Basement Basement The Duke of Flies/Larry Jr. Dingle/Gurglings
Cellar Cellar Widow/Blighted Ovum Baby Plum/Little Horn/The Haunt
Burning Basement Burning Basement Turdlings/Little Horn Rag Man
Downpour Downpour The Rainmaker Lil Blub/Min-Min
Dross Dross Lil Blub Clog/Turdlet
Caves Caves Gurdy Jr./2 Needles, 1 Pin/Peep Mega Maw/Polycephalus
Catacombs Catacombs Gurdy Jr./The Stain/The Wretched Carrion Queen/Dark One
Flooded Caves Flooded Caves The Stain/Rag Mega Big Horn/The Frail
Mines Mines Larry Jr. and 1 Tuff Twin Reap Creep
Ashpit Ashpit The Pile The Shell/Singe
Depths Depths 2 Little Horns/Monstro II The Bloat/The Gate
Necropolis Necropolis The Adversary/The Pile The Cage/Mask of Infamy
Dank Depths Dank Depths 2 Little Horns/2 Rag Men Brownie/Sisters Vis
Mausoleum Mausoleum The Heretic The Siren
Gehenna Gehenna The Visage The Horny Boys
Womb Womb 3 Gurglings/The Stain The Bloat/The Cage
Utero Utero Daddy Long Legs/Teratoma The Bloat/2 Gurdy Jr.s
Scarred Womb Scarred Womb Fistula/Gurgling + Gurdy Jr Mama Gurdy/The Bloat/The Matriarch
Corpse Corpse 2 Chubs/Chimera The Scourge


The following room maps were made using Basement Renovator for cleaner viewing; note that both normal and boss challenge rooms use the same layouts.

ID Weight Notes Image preview
0-2 1.0 This room appears three times in the room pool, making it three times more likely to appear than normal. Challenge 0-2.png
3-4 1.0 This room appears twice in the room pool, making it twice as likely to appear than normal. Challenge 3-4.png
5 0.5 The item will be from the Treasure Room pool. Challenge 5.png
6 1.0 Challenge 6.png
7 0.75 Challenge 7.png
8 0.5 Challenge 8.png
9 0.5 Challenge 9.png
10 0.5 Challenge 10.png
11 1.0 Challenge 11.png
12 1.0 Challenge 12.png


  • Added in Afterbirth The waves appear in random orders rather than the orders listed above.
  • If Isaac has some way to teleport out of the room, the contents of the Challenge Room can be taken without fighting the enemies.
    • If a trigger to start a challenge room is left in the room after teleporting out (such as a chest or active item) or an item is spawned in the room and collected (such as rewards from Beggars or Blood Donation Machines), the challenge room will start over when it is picked up/opened.
  • If a Secret Room is next to a Challenge Room, it can be entered by using a bomb in the Secret Room on the wall separating the two rooms. However, the entrance to the Secret Room from the Challenge Room closes itself, meaning Isaac cannot escape through the Secret Room entrance.
    • Added in RepentanceIf the Secret Room contains Greed you will be unable to enter the challenge room from it.
    • Added in Repentance If the player bombs into a Boss Challenge Room through a Secret Room and leaves, the bombed entrance will close permanently until Isaac has one heart or less of health.
  • If Spiders spawn from a Red Chest before or during a wave, the Spiders have to be killed in order for the waves to start/continue.
    • If Spiders spawn from a Red Chest after the challenge room is cleared, the player can leave the room without fighting them.
  • Because of the health requirements, both types of Challenge Room will always be open for Removed in Repentance??? ??? andThe Lost The Lost.
    • Added in RepentanceBecause the Boss Challenge Room takes soul hearts into account, you can't enter the room with more than 1 heart total, so characters like ??? ??? have to be at one heart to enter them now.
  • Doors to challenge rooms can be opened with Added in Afterbirth †15►Mr. ME! Mr. ME!


Bug Bug! Removed in Afterbirth † If the game crashes or you close it before you finish the challenge room it will crash every time you try to continue that run.
Bug Bug! If you encounter Greed or Super Greed in a secret room next to a boss challenge room, the path to the boss challenge room is boarded up from the mini-boss fight. Defeating Greed or Super Greed does not remove the boards, despite the room no longer being active.

SmallIsaac.png Rooms SmallIsaac.png

Unlocked Added in Afterbirth Added in Afterbirth †
Boss Room Icon.png
Boss Room
Mini-Boss Room Icon.png
Mini-Boss Room
Curse Room Icon.png
Curse Room
Sacrifice Room Icon.png
Sacrifice Room
Room 1x1 small.png
Room 1x1.png
Grave Room
Locked Added in Repentance
Treasure Room Icon.png
Treasure Room
Shop Icon.png
Library Icon.png
Planetarium Icon.png
Slotted Arcade Icon.png
Barred Challenge Room Icon.png
Challenge Room
Boss Challenge Room Icon.png
Boss Challenge Room
Double-locked Vault Icon.png
Dice Room Icon.png
Dice Room
Double-boarded Bedroom Icon.png Bedroom2 Icon.png
Hidden Added in Repentance
Secret Room Icon.png
Secret Room
Super Secret Room Icon.png
Super Secret Room
Super Secret Room Icon.png
Crawl Space
Super Secret Room Icon.png
Black Market
Super Secret Room Icon.png
Ultra Secret Room Icon.png
Ultra Secret Room
Post-boss Added in Afterbirth
Devil Room Icon.png
Devil Room
Angel Room Icon.png
Angel Room
Super Secret Room Icon.png
Boss Rush
Super Secret Room Icon.png
Blue Womb Entrance
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