Binding of Isaac: Rebirth Wiki

The Boss Rush is an optional room that becomes available by beating Mom in Depths Depths, Necropolis Necropolis, or Added in Afterbirth Dank Depths Dank Depths within 20 minutes, or beating her in Added in Repentance Mausoleum Mausoleum or Gehenna Gehenna within 25 minutes.

In the center of a large room, there will be 4 random items to choose from (Picked from the Treasure Room (Item Pool)). Picking up an item will cause the other three to disappear and start the Boss Rush. Completing the Boss Rush will also reward 1 more item, separate from the 4 seen when first entering the room.

Added in Afterbirth There is a chance that there will only be 2 items to choose from. Additionally, items may be trapped behind rocks or spikes. Items may appear in the corners of the room instead of the center.

Added in Afterbirth † There is a small chance that there will be 8 items to choose from.


The Boss Rush consists of 15 waves with 2 bosses per wave. The next wave does not spawn until both bosses from the previous wave have been killed, and any lingering monsters from previous waves will not prevent the next wave from spawning.

Occasionally, all the bosses fought in the Boss Rush will be their Champion variants, if they have one.


All 15 waves are predetermined.


All 15 waves are randomized, with each wave spawning two random bosses from the list. Each boss can only appear once per Boss Rush, meaning that out of all the 50 bosses Isaac will face 30 of them.

Boss Entity ID
3x Larry Jr. 19.0
3x The Hollow 19.1
Monstro 20.0
Chub 28.0
C.H.A.D. 28.1
Carrion Queen 28.2
Gurdy 36.0
Monstro II 43.0
Gish 43.1
Pin 62.0
The Frail 62.2
Famine 63.0
Pestilence 64.0
War 65.0
Death 66.0
The Duke of Flies 67.0
The Husk 67.1
Peep 68.0
The Bloat 68.1
Loki 69.0
Fistula 71.0
Blastocyst 74.0
Gemini 79.0
Steven 79.1
Blighted Ovum 79.2
The Fallen 81.0
The Headless Horseman 82.0
Mask of Infamy 97.0
Gurdy Jr. 99.0
Widow 100.0
The Wretched 100.1
3x Gurglings 237.1
3x Turdlings 237.2
The Haunt 260.0
Dingle 261.0
Dangle 261.1
Mega Maw 262.0
The Gate 263.0
Mega Fatty 264.0
The Cage 265.0
Dark One 267.0
The Adversary 268.0
Polycephalus 269.0
Uriel 271.0
Gabriel 272.0
The Stain 401.0
Brownie 402.0
The Forsaken 403.0
Little Horn 404.0
Rag Man 405.0

Note that all of the chapter 4 bosses (except Blastocyst and Death) are not present in the Boss Rush:

Furthermore, some other bosses are not present in the Boss Rush:



  • If Mom is beaten within 20 minutes and Isaac enters the Devil Room, he must return to the boss room before 20 minutes have passed; otherwise, the Boss Rush entrance will be closed.
    • If Isaac is teleported to the Devil Room while inside the Boss Rush room (for example, using a Joker Joker card), exiting the Devil Room will lead him to Mom's Boss Room.
  • If Isaac dies during the Boss Rush, but is able to respawn, the entrance to the Boss Rush room will still be open if the timer is still under 20 minutes. If the Boss Rush entrance has closed, the room can still be re-entered by dying in the Mom boss fight room at the cost of another life.
  • The Boss Rush can only be retried by picking up an item off a pedestal in its room. If the item Isaac originally picked from the room was an active type, the pedestal and item it was swapped out for will still be there. Swapping the items again will restart the fight. Alternatively, a new pedestal can be created, such as through a XX - Judgement XX - Judgement card, or dropping your active item via Added in Afterbirth †Butter! Butter! and taking its item will also restart the fight. Also, having Broken Shovel in your possession will automatically start the Boss Rush if left and entered again.
  • Added in Afterbirth If a Sack spawns for whatever reason, picking it up will start the Boss Rush. The player can still pick up one of the pedestal items.
  • The boss rush does not unlock anything if beaten in a challenge.
  • Added in Afterbirth † Using Void Void, Black Rune Black Rune, Added in RepentanceAbyss Abyss, or Added in RepentanceMoving Box Moving Box will start the Boss Rush.
  • If a chest is opened in the Boss Rush room, it will start the Boss Rush.
  • Added in Afterbirth †Mama Mega! Mama Mega! will open the Boss Rush room even if the time limit has expired.
  • Holding Added in Afterbirth †Broken Shovel Broken Shovel will also open the Boss Rush room, ignoring the time limit, to complete Added in Afterbirth †Mom's Shovel Mom's Shovel.
  • If a Crawl Space is entered from within the Boss Rush room, exiting the Crawl Space will not return the player to the Boss Rush room, but will instead place the player back in the Mom Boss Room.
  • When Added in RepentanceSuplex! Suplex! is used while a Added in RepentanceBerserk! Berserk! effect is active, Isaac lands with an explosion simiar to Added in Afterbirth †Mama Mega! Mama Mega!. This explosion can open the boss rush door after the time limit has expired.


  • The player's playtime can be checked at any moment by pressing TAB (or long-pressing SELECT on the controller), enabling Extra HUD in the options menu, or by simply looking down to the bottom screen on the 3DS version, where it is shown on the map.
  • Each boss will always drop Hearts on normal difficulty, Added in Repentance and sometimes on hard difficulty. Dark Bum Dark Bum can turn red hearts from these drops into Removed in RepentanceSoul Hearts (Added in RepentanceBlack Hearts), providing loads of extra health.
  • Take out Carrion Queen quickly, as its red poops will remain for the rest of the boss rush. They can be advantageous though, as other bosses can also take damage from these poops. In particular, bouncing bosses like The Hollow and The Husk can quickly kill themselves on contact.
  • All bosses with Brimstone Brimstone laser attack could severely hurt or even one-shot-kill each other, especially Added in Afterbirth The Gate. It may be beneficial to focus on the other boss before killing them.
  • Wave 9 can be quite difficult as Monstro II (he always spawns on the left side) can catch the player off guard with an offscreen Brimstone Brimstone laser. The black creep left by Gish will remain until he is killed.
  • The Bloat + Mask of Infamy is one of the hardest waves, but The Bloat can be baited into destroying both the heart and the mask itself of the Mask of Infamy with its Brimstone Brimstone lasers.
  • Any teleport effect (such as cards, activated items, Telepills, etc) can be used to leave the Boss Rush. This can be used to gain one item without having to fight any bosses.

Unlockable Achievements[]



  • Despite battling bosses from the floors before, a few bosses from Womb Womb will spawn such as Blastocyst and Death.
  • Despite the Timer seen between level transitions appearing, Boss Rush cannot be done the first time the player defeats Mom. Instead, the game will cut directly to the Epilogue.
  • Added in Repentance Armageddon is the theme for the Boss Rush added in The Binding of Isaac: Repentance.


Bug Bug! It is possible for item pedestals to spawn on red poop (which can be spawned by Carrion Queen or red Dingle) or spikes. Attempting to pick up the item will damage Isaac.
Bug Bug! One of the possible layouts for the Boss Rush room will have spikes near the location that an item pedestal spawns after completing the fight. If you possess There's Options There's Options, one of the item pedestals can appear in the same place as the spikes, causing you to take damage by picking that item up.
Bug Bug! Entering Boss Rush after the 20 minutes (killing Mom before it, but waiting to enter) and using Glowing Hour Glass will crash the game.