Binding of Isaac: Rebirth Wiki

Tear Height[]

Tear height is a hidden attribute that determines how far above the ground tears travel, and in practice increases effective range. Very high tear height makes Isaac's tears' "cruising altitude" so high they can cross over obstacles as if they were spectral, but they won't go through the room walls. Once the tears fall down, they will start hitting obstacles again. This compounds with the starting height from the range stat.

Items that Affect Tear Height[]

Passive Items[]

Name ID Icon Quote Description Added in Repentance Quality
Blood Clot 5.100.254 Blood Clot DMG + range up Tears fired from the left eye have +1 flat damage, +5 range, and +0.5 tear height. 2
Dead Onion 5.100.336 Dead Onion Toxic aura tears Grants piercing and spectral tears. Increases tear size (without increasing damage) while greatly reducing range and shot speed. 3
Godhead 5.100.331 Godhead God tears Removed in Repentance Grants homing tears with a damaging halo. +0.5 Damage, -0.3 Tears -0.3 Shot Speed, +0.8 Tear Height, and +1.2 Range.
Added in Repentance Grants homing tears with a damaging halo. +0.5 Damage, -0.3 Tears -0.3 Shot Speed, and +0.8 Tear Height.
Ipecac 5.100.149 Ipecac Explosive shots Replaces tears with explosive and poisoning projectiles fired in an arc from the mouth. 4
Jesus Juice 5.100.197 Jesus Juice Damage + range up +0.5 damage, +0.25 range, +0.5 tear height. 2
Magic Mushroom 5.100.12 Magic Mushroom All stats up! Makes Isaac bigger. Adds one Red Heart Container, +0.3 Damage, x1.5 damage multiplier, Removed in Repentance +5.25 / Added in Repentance +1.5 Range, and +0.3 Speed, and restores all Health. 4
Mini Mush 5.100.71 Mini Mush Speed + range up Decreases Isaac's size, making him less likely to be hit. Removed in Repentance+0.3 speed, +1.5 tear height, -4.25 range (effective range is increased). Added in Repentance +0.3 speed, +1.50 range. 2
Mom's Contacts 5.100.110 Mom's Contacts Freeze effect +0.25 range. Adds a chance to shoot petrifying tears, which stop enemies in place and prevent them from moving or attacking. 3
Mom's Heels 5.100.30 Mom's Heels Range up +5.25 range, +0.5 tear height. Added in Repentance Enemies that touch Isaac take 12 damage. 1
Mom's Lipstick 5.100.31 Mom's Lipstick Range up +5.25 range, +0.5 tear height. Added in Repentance Red Heart Heart. 1
Mom's Underwear 5.100.29 Mom's Underwear Range up +5.25 range, +0.5 tear height. Added in Repentance Spawns 3-6 Blue Flies on pickup. 1
My Reflection 5.100.5 My Reflection Boomerang tears Gives Isaac's tears a boomerang effect. +1.5 range, +1 tear height, x1.6 shot speed multiplier. 0
Number One 5.100.6 Number One Tears up + range down Grants +1.5 tears, but severely reduces range. 2
Odd Mushroom 5.100.121 Odd Mushroom HP + DMG up, speed down Grants one empty Heart container, +0.3 damage, +0.25 range, +0.5 tear height, and -0.1 speed. 2
Roid Rage 5.100.14 Roid Rage Speed and range up Removed in Repentance +0.6 speed, +5.25 range, +0.5 tear height.
Added in Repentance +0.3 speed, +1.50 range, +0.5 tear height.
Sacred Heart 5.100.182 Sacred Heart Homing shots + DMG up Removed in Repentance Adds a Red Heart Container. Grants homing tears, a x2.3 Damage multiplier, +1 flat Damage, -0.4 Tears, -0.25 Shot Speed, and +4.125 Range.
Added in Repentance Adds a Red Heart Container. Grants homing tears, a x2.3 Damage multiplier, +1 flat Damage, -0.4 Tears, and -0.25 Shot Speed.
Safety Pin 5.100.339 Safety Pin Evil + range + shot speed up Grants one Black Heart Black Heart, +5.25 range, +0.5 tear height, +0.16 shot speed. 1
Synthoil 5.100.345 Synthoil DMG + range up +1 damage, +5.25 range, +0.5 tear height. 3
The Halo 5.100.101 The Halo All stats up Grants one full Red Heart container, +0.3 damage, +0.2 tears, +0.25 range, +0.3 speed, and +0.5 tear height. Added in Repentance Heals 1 additional Red Heart Red Heart. 2
Tiny Planet 5.100.233 Tiny Planet Orbiting tears + range up Massively increases Range and grants spectral tears. Tears orbit around Isaac at a fixed distance until they hit the ground. 0
Added in Afterbirth Continuum 5.100.369 Continuum Transcendent tears Grants spectral tears and increases range. Tears travel through walls and appear at the opposite side of the room. 2
Added in Afterbirth Kidney Stone 5.100.440 Kidney Stone Matt's kidney stone Randomly while firing tears, Isaac will stop firing and turn red, where he will charge and release a lot of 'tears' in one go. The burst of tears also includes a kidney stone, which deals a lot of damage. 2
Added in Afterbirth Marked 5.100.394 Marked Directed tears Isaac will automatically fire tears directed at a red target on the ground. The target can be moved with tear controls. +0.7 tears, +3.15 range. 1
Added in Afterbirth Mom's Pearls 5.100.355 Mom's Pearls Range + luck up +1.25 range, +0.5 tear height, +1 luck. Added in Repentance Grants one Soul Heart Soul Heart. 2
Added in Afterbirth Mr. Dolly 5.100.370 Mr. Dolly Range + tears up +0.7 tears, +5.25 range, +0.5 tear height, spawns 3 random types of Red Heart Hearts on the floor when picked up. 3
Added in Afterbirth Purity 5.100.407 Purity Aura stat boost Boosts one of Isaac's stats depending on the color of the aura around him. The aura disappears upon taking damage and reappears with a random color upon entering a new room. Red boosts damage, blue boosts tears, yellow boosts speed, and orange boosts range. 3
Added in Afterbirth Tractor Beam 5.100.397 Tractor Beam Controlled tears Isaac emits a beam from his face that his tears are bound to. Removed in Repentance Increases Tears, Range, and Shot Speed. Added in Repentance Increases Fire Rate, Range, and Shot Speed. 3
Added in Afterbirth † Compound Fracture 5.100.453 Compound Fracture Bone tears! Increases Range. Tears turn into bones, which shatter into 1-3 bone shards upon hitting an enemy or obstacle. 3
Added in Afterbirth † Dark Prince's Crown 5.100.442 Dark Prince's Crown Loss is power Removed in Repentance When at exactly one Red Heart Red Heart, increases tears, range, tear height, and shot speed.
Added in Repentance When at exactly one Red Heart Red Heart, increases fire rate, range, tear height, and shot speed.


Name ID Icon Quote Description
Added in Afterbirth Lazy Worm 5.350.66 Lazy Worm Pft Increases range by 4 and decreases shot speed by .4.
Added in Afterbirth Tape Worm 5.350.65 Tape Worm Floooooooooop! Doubles Isaac's range and halves his tear height.
Added in Afterbirth † Ouroboros Worm 5.350.96 Ouroboros Worm Foop foop! Tears travel in a large spiral pattern and gain spectral, with a small chance to gain homing. Added in Repentance Also adds +0.4 Tears.


  • Added in Afterbirth In co-op, Long Baby will occasionally briefly increase range, shot speed, and tear height. Dark Baby will occasionally briefly increase all stats, including tear height.
  • Azazel Azazel starts with -1 tear height, though the stat does not affect his short-range Brimstone.


Knockback is a mechanic that determines how far an entity is pushed back by a certain force.

Tear Knockback[]

This knockback comes from Tears, most notably Isaac's. The knockback force is determined by the speed and direction of the tear, which itself is determined by Isaac's movement and Shot Speed. For example, Ring Worm Ring Worm does not increase the knockback stat, but does affect knockback as the tear's speed hits extremes of very fast and very slow; hitting enemies with the fastest moment of its arc applies significant knockback. Damage does not affect the knockback.

Upon collision, the tear applies two seperate knockbacks on the enemy. One is collision knockback which pushes the enemy away from the tear. The other one is momentum knockback which pushes the enemy toward the tear's movement direction. Since they can have directional difference, the two knockbacks can cancel each other in some rare cases.


  • Vp is the tear's velocity.
  • K is knockback multiplier, which is 1.7 by default but is counted as 0 when the knockback multiplier is not active.
  • Mp is the tear's mass, which is 8 by default.
  • Mt is the enemy's mass.

Knockbacks from laser is:

The knockback multiplier does not affect lasers' knockback.

Knockback items affect the knockback in many ways, by activating the knockback multiplier, increasing the knockback multiplier, and/or increasing the tear mass. Effects that increase the knockback multiplier do not stack, and only the highest increase applies. Effects that increase the tear mass do not stack. Soy Milk Soy Milk or Added in RepentanceAlmond Milk Almond Milk decrease the tear mass, thus weakening the knockback.

Items that Affect Tear Knockback[]

Passive Items[]

Name ID Icon Quote Description Added in Repentance Quality
Pisces 5.100.309 Pisces Tears up + knock-back shots Removed in Repentance -1 Tear Delay, adds knock-back shots and increases tear size.
Added in Repentance +0.5 Fire Rate, adds knock-back shots and increases tear size.
Soy Milk 5.100.330 Soy Milk DMG down + tears way up Tears are smaller and do much less damage, but fire in very rapid succession. 2
Added in Afterbirth 8 Inch Nails 5.100.359 8 Inch Nails Stick it to 'em! +1.5 damage. Replaces Isaac's tears with nails, which have increased knockback. 3
Added in Repentance Almond Milk 5.100.561 Almond Milk DMG down + tears up + you feel nutty Quadruples fire rate, with x0.3 damage multiplier. Tears are given random worm trinket effects. 1
Added in Repentance Terra 5.100.592 Terra Born to rock +1 Damage. Replaces tears with rocks that deal variable damage, have increased knockback, and can destroy obstacles. 3


Name ID Icon Quote Description
Added in Afterbirth Blister 5.350.77 Blister Bounce back! Increases knockback of tears.


  • Directional knockback affects most enemies, including bosses (except for stationary ones like Pin or Round Worm). Items (both trinkets and pickups) cannot be moved by tears, except for live bombs.
  • Knockback from tears provides minor crowd control for homing enemies like flies or Gapers, increasing the time it takes them to reach Isaac.
  • Be wary of the natural knockback from tears when trying to dodge charging enemies (like the smaller twin of Gemini, Gurglings, and Leeches): The tears can push them off-track and towards the direction you are planning to escape to.

Knockback from other sources[]

Various sources also can cause knockback. This knockback is often a little shockwave that's emitted at a certain radius in all directions, most prominently from explosives, like Bombs. Certain farts also create a knockback. Some enemies, like the Fatty, can fart, and Isaac can also do so with certain items.

Pickups (including chests) are affected by this knockback; items, however, are not.

Knockbacks from Added in RepentanceBelly Jelly Belly Jelly, Added in RepentanceButter Bean Butter Bean, Added in RepentanceDivine Intervention Divine Intervention, Added in RepentanceHemoptysis Hemoptysis, and Added in RepentanceKnockout Drops Knockout Drops are strong knockback. They do not decrease from the enemy's friction and linger for a relatively long time once applied. Any enemy affected by it takes 10 + 2 × (floor - 1) damage upon being pushed into walls or obstacles. No other knockback can deal such damage however strong it is.

Items that Cause Knockback[]

Activated Items[]

Name ID Icon Quote Description Added in Repentance Quality
Butter Bean 5.100.294
Butter Bean
3 seconds
Reusable knock-back Upon use, Isaac farts and knocks back nearby enemies Added in Afterbirth and projectiles. Added in Repentance Enemies pushed into walls or obstacles take 12 damage. 1
The Bean 5.100.111
The Bean
1 rooms
Toot on command Isaac farts, poisoning any enemy in close range. 0
The Poop 5.100.36
The Poop
1 rooms
Plop! Spawns a pile of Poop Poop where Isaac is standing and knocks back nearby enemies. May yield pickups like regular poop. 0

Passive Items[]

Name ID Icon Quote Description Added in Repentance Quality
Isaac's Heart 5.100.276 Isaac's Heart Protect it Isaac himself is now immune to all damage, and a heart familiar follows him. If the heart is hurt, Isaac is hurt. Added in Repentance The heart charges up as Isaac shoots, firing 8 blood shots, knocking back enemies, and leaving a puddle of creep when released. 0
The Black Bean 5.100.180 The Black Bean Toot on touch When taking damage, Isaac farts, causing poison damage to all enemies in range. 0
Added in Afterbirth Farting Baby 5.100.404 Farting Baby He farts! Spawns a familiar that follows Isaac and blocks enemy shots. If a shot hits Farting Baby, it has a chance to fart, which charms, poisons, or knocks back nearby enemies. 1
Added in Repentance Belly Jelly 5.100.690 Belly Jelly Bounce away! Causes enemies to bounce off of Isaac, dealing damage to them if they hit an enemy or obstacle. Also gives Isaac the chance to deflect enemy shots. 3
Added in Repentance Hemoptysis 5.100.726 Hemoptysis Double tap sneeze Double-tapping a fire button causes Isaac to sneeze blood, dealing damage to enemies in front of him. 2
Added in Repentance Knockout Drops 5.100.637 Knockout Drops They pack a punch! Adds a chance to shoot a fist tear that has extremely high knockback and confuses enemies. 3


Name ID Icon Quote Description
Butt Penny 5.350.24 Butt Penny Wealth of gas Isaac will fart when he picks up a coin. Coins have a higher chance to drop from Poop Poops.
Mysterious Candy 5.350.25 Mysterious Candy Uh-oh! Isaac farts or poops at random intervals. Getting hit can also trigger the effect.