Binding of Isaac: Rebirth Wiki

Added in Afterbirth

Multidimensional Baby is a passive item added in The Binding of Isaac: Afterbirth.


  • Spawns a familiar that follows Isaac's path with a 2-second delay.
    • Added in Repentance The delay is 0.66 seconds instead.
  • When a friendly tear passes through Multidimensional Baby, the tear splits into two parallel tears that gain a 1.33x speed boost, +4 shot height, and also a visual black and white flashing effect.


  • It is possible to crash the game when combining this item with rapid-fire or multi-shot laser tears.
  • Duplicated tears will deal the same damage as Isaac's tears.
  • If other familiars that move with a similar pattern such as Added in Afterbirth †Shade Shade have been collected before the Baby, it will follow them instead with further delay.
  • Standing perfectly still with the Multidimensional Baby inside of Isaac will activate its effect, as the tears will pass through it as they spawn.
    • This does not work with attacks such as Brimstone.
  • Added in RepentanceThis item belongs to the Conjoined set. Collecting three items from this set will transform Isaac into a three-faced version of himself.


  • Brimstone Brimstone: If a brimstone laser is shot through the baby, it will double the laser.
    • Azazel Azazel's short-ranged Brimstone attack will also be "fired again" from the baby, increasing the range.
  • Cricket's Body Cricket's Body/The Parasite The Parasite: Tears that pass through Multidimensional Baby will duplicate and their split tears will duplicate. Half of the tears fired through Multidimensional Baby retain The Parasite's look and the other half have the flashing appearance.
  • Added in Afterbirth †Haemolacria Haemolacria: Haemolacria shots will be duplicated and more burst tears will spawn. Burst tears that pass through Multidimensional Baby will also be duplicated.
  • Added in Repentance Papa Fly Papa Fly: Papa Fly will always shoot two shots due to both familiars having the same movement delay.
  • Added in RepentanceRevelation Revelation: If a revelation laser is shot through the baby, it will double the laser.
  • Shooting familiars: Duplicates familiar's tears.
  • Added in Afterbirth †Sprinkler Sprinkler: Tears fired by the sprinkler can be duplicated.
  • Technology Technology: When the laser passes through Multidimensional Baby, it doubles the laser.


  • ???'s Soul ???'s Soul/Abel Abel/Cain's Other Eye Cain's Other Eye: Familiar tears will be duplicated if they pass through the baby. However, due to their independent movement pattern, it can be hard to achieve duplication.
  • Anti-Gravity Anti-Gravity: Multidimensional Baby will travel the same path as the Anti-Gravity tears, easily doubling any stationary shots. Any moving tears that hit it will produce a normal moving copy, however stationary tears will spawn a copy that will eventually fall to the ground even after the direction is released.
    • Added in Afterbirth † Stationary duplicated tears will release normally.
  • Added in Afterbirth †Baby-Bender Baby-Bender: No effect as Multidimensional Baby only duplicates Isaac's tears.
  • BFFS! BFFS!: The baby is larger, but tears shot through it will not do more damage.
  • Box of Friends Box of Friends: Each copy of Multidimensional Baby follows the previous copy with a 2-second (Added in Repentance0.66-second) delay. Tears shot through multiple babies will only be duplicated once.
  • Added in Afterbirth †Compound Fracture Compound Fracture: Tears that pass through Multidimensional Baby will be duplicated and cosmetically look like normal tears. Bone shards will not duplicate unless they pass through Multidimensional Baby separately.
  • Dr. Fetus Dr. Fetus: No effect.
  • Epic Fetus Epic Fetus: No effect.
  • Added in RepentanceEye of the Occult Eye of the Occult: Makes it more easy to use Multidimensional Baby, as Isaac can simply stand while the familiar stays on top of him.
  • Added in Afterbirth †Lachryphagy Lachryphagy: Duplicates tears, which tend to merge after traveling a certain distance, making it easier to feed tears. Burst tears can only be duplicated if the tear they come from didn't pass through the baby already.
  • Lil Brimstone Lil Brimstone/Robo-Baby 2.0 Robo-Baby 2.0: Familiar lasers that pass through the baby will not be duplicated.
  • The Ludovico Technique The Ludovico Technique: Spawns another tear that will slowly follow Isaac but cannot be controlled.
    • Added in Repentance Spawns a stationary tear where Multidimensional Baby first appeared in the room. The tear does not follow Isaac.
  • Added in RepentanceMom's Bracelet Mom's Bracelet: Throwing any obstacles through Multidimensional Baby will transform it into two 40 damage tears. Throwing obstacles that can drop pickups like mushrooms through Multidimensional Baby will cease the possibility of anything dropping from such tears. Crawl spaces, though, appear right after picking up an obstacle.
  • Removed in RepentanceMom's Knife Mom's Knife: No effect.
    • Added in RepentanceFired knife is doubled when passing through Multidimensional Baby. No effect on held knife and returning knife.
  • Tech X Tech X: No effect.
  • Added in Afterbirth †Trisagion Trisagion: No effect.

In-game Footage[]


  • The way the tear splits resembles stimulated light emission.
  • In the initial release of The Binding of Isaac: Afterbirth, the flashing effect that Multidimensional Baby gave tears was much more intense, and made some players feel nauseous. This was changed in version v1.06.0052.


Bug Bug! Switch Can double Best Friend when it passes through.


PC Normal and hard modes only 3BGY TK8J (Treasure Room adjacent to spawn)