Binding of Isaac: Rebirth Wiki

(except in Rebirth)

BRAINS! is Challenge #27, added in The Binding of Isaac: Afterbirth. This challenge is played as Character ??? (Character) icon??? and you start blindfolded, with 3 Collectible Bob's Brain iconBob's Brain, Collectible Thunder Thighs iconThunder Thighs and (in Repentance) the BobBob transformation. The goal is to defeat Boss ??? ingame???. Treasure Rooms do not spawn in this Challenge.

Difficulty[ | ]

Bob's Brain is a difficult item to use, as it is not only easy to do one full heart of self-damage when fighting enemies, it also leaves Character ??? (Character) icon??? exposed while waiting for the brains to respawn. Adding to the problem is that playing as Character ??? (Character) icon??? forbids obtaining Red Hearts. With no Treasure Rooms and having to reach ChestChest, lots of skill and luck are necessary to beat this challenge.

Strategy[ | ]

  • Make sure to pick up Collectible The Polaroid iconThe Polaroid after the fight against Mom. If Collectible The Negative iconThe Negative is chosen instead, Character ??? (Character) icon??? will not be teleported to ChestChest after the CathedralCathedral, ending the challenge without a victory.
    • (in Afterbirth † and Repentance) Only The Polaroid can be taken, as The Negative won't spawn.
  • Try to space out the shots with Bob's Brain so their respawn time isn't as long. Achieving a rhythm makes it much easier to efficiently kill enemies, especially bosses, without taking as much damage.
  • Any method of damaging enemies besides Bob's Brain is incredibly helpful.
    • (in Afterbirth † and Repentance)Collectible Sharp Straw iconSharp Straw is incredibly useful as it can be used multiple times per room, does high amounts of damage to any enemy (including bosses), may drop Half Soul Hearts and does not require aim to use. For it to be obtained, however, one must purchase Collectible Chaos iconChaos from a Shop, or survive until reaching ChestChest.
    • Like any blindfolded run, familiars are useful for this challenge. Not only can they safely extinguish fires (except Collectible Rotten Baby iconRotten Baby), they can help take care of weak or weakened enemies while the brains respawn. However, you do have to hold the firing keys to make them attack (excluding Collectible Succubus iconSuccubus), increasing the risk of harming Character ??? (Character) icon??? by one of the brains exploding in close quarters. Most strong familiars are also exclusive to Devil Rooms, so ??? must maintain health if wanting them without putting the run at risk.
      • Most of Character Lilith iconLilith's unlockables are especially valuable in this run; Collectible Incubus iconIncubus and Succubus are among the most powerful familiars, while Collectible Box of Friends iconBox of Friends can double any familiars. Taking the time to unlock these can be beneficial for this challenge.
      • Other good familiars aside from Incubus and Succubus include Collectible Demon Baby iconDemon Baby, who fires on its own, Collectible Lil Brimstone iconLil Brimstone, who can hit multiple enemies per shot, and Rotten Baby, whose flies will home in on enemies.
    • The damaging trails from the BobBob transformation or Collectible Headless Baby iconHeadless Baby can be useful, allowing chasing enemies to be killed without the risk of taking damage from Bob's Brain. However, this method takes a lot of time and is useless against flying enemies.
      • Lost Cork makes your starting green creep even more effective, helping negate the reliance on your Bob's Brains for damage.
    • Buying Collectible The Candle iconThe Candle or Collectible Red Candle iconRed Candle from the Shop can make this challenge a lot easier, since both do a lot of damage and can be used in a room multiple times.
    • Orbitals, such as Collectible Cube of Meat iconCube of Meat and Collectible Sacrificial Dagger iconSacrificial Dagger, can be a good source of damage. Make sure to not press the firing keys while orbitals do damage, as it will harm ??? if having at least one brain.
      • Once Collectible The Polaroid iconThe Polaroid is obtained, orbitals start becoming more useful. Since the shield will always trigger from any damage, it will give a little time to run into enemies and deal contact damage, preferably against weaker enemies to save the brains for stronger ones.
  • Collectible Pyromaniac iconPyromaniac and Collectible Host Hat iconHost Hat make this challenge much easier, as ??? no longer takes damage from the brain's explosions.
  • Use Thunder Thighs to break Rocks, as this can sometimes open a Crawl SpaceCrawl Space with items such as Pyromaniac.
    • Also, keep an eye out for Tinted Rocks, as they can have valuable Soul HeartSoul Hearts, as well as pickups and items via Locked Chests. Thunder Thighs allows ??? to break them for free, so there is no reason to skip any of them. But it is not advised to pick up Collectible The Small Rock iconThe Small Rock unless having items that depend on the damage stat, as it lowers his already low speed.
    • (in Repentance) You can destroy Mushrooms safely because the BobBob transformation grants poison immunity, giving you a chance to obtain Collectible Magic Mushroom iconMagic Mushroom.
  • Speed items help keep a distance from chasing enemies, making it easier to avoid taking splash damage from a brain's explosion. Since Thunder Thighs slows ??? down, at least one or two speed items are necessary to outrun most enemies.
    • (in Repentance) The creep generated by the Bob transformation can be used defeat ground-based, chasing enemies in close quarters, eliminating the risk of using Bob's Brain with a little patience.
  • Flying is very useful to give more breathing room by preventing Character ??? (Character) icon??? from becoming cornered in a troublesome room layout, as well as negating the threat of Spikes or creep.
  • IV - The EmperorIV - The Emperor can be extremely valuable, especially in the late game, because it allows skipping of difficult floors like the CathedralCathedral and ChestChest to go straight to the boss, minimizing the amount of fighting required.
  • Keep an eye out for Libraries, as there are many good defensive, or health-related items that can be obtained, like Collectible Book of Revelations iconBook of Revelations and Collectible Book of Shadows iconBook of Shadows.
    • If ??? has a surplus of health available in an early Devil Room, Collectible Satanic Bible iconSatanic Bible is also a viable option.
  • If damage via an enemy is unavoidable, collide with the enemy first and then blow it up with a brain while invincibility frames last. ??? will get hurt either way, but he will only lose half a heart instead of a full heart. However, this strategy does not work against Champion enemies (if it does two full hearts of damage, it is a better idea blowing it up instead) and enemies that naturally do one full heart of damage (like ChubberChubbers), and ??? will always take a full heart of damage anyway starting from WombWomb.
  • ??? can bridge one-tile gaps by pushing PoopPoop or Rocks into them, using Thunder Thighs or The Poop.
  • (in Repentance)Collectible Revelation iconRevelation's angel beam will still work just fine even though ??? is Blindfolded, and as such, grants an extremely effective method of offense outside of the main Bob's Brain attacks. It is highly recommended to aim for Angel Rooms for this item alone, given its infinite range and strong DPS, as well as being completely safe due to lack of self-damage and the added benefit of flight.
    • Similarly,Collectible Maw Of The Void iconMaw Of The Void also works while blindfolded, albeit without nearly as much range.
  • (in Repentance) If Boss Baby Plum ingameBaby Plum is encountered early in the run, it may be beneficial to simply let her leave and obtain the (in Repentance)Collectible Plum Flute iconPlum Flute as an early replacement for the Poop.

Notes[ | ]

  • (in Afterbirth †) If entering The VoidThe Void after killing Boss Mom ingameMom or Boss Mom's Heart ingameMom's Heart/ Boss It Lives ingameIt Lives, it is still possible to collect the trophy by defeating Boss Delirium ingameDelirium. However, this is extremely inadvisable due to the limited attack options available and offers no benefit.

Reward[ | ]