Hidden Attributes

## Tear Falling Speed

**Tear falling speed** is a hidden attribute that determines how far above the ground tears travel after traveling for a short period of time, and in practice increases effective range. Very high tear falling speed makes Isaac's tears arc upward then continue along "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 height from the tear height stat.

* Items no longer give tear falling speed directly, instead tear falling speed is dynamically generated based on the range stat, shot speed stat, and tear height stat, in order to match the range stat in tiles.

###  Items that Affect Tear Falling Speed

#### Other

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

## Tear Height

**Tear height** is a hidden attribute that determines the height that tears spawn at. Before Repentance, this was the range stat displayed in the found hud, and most items that affected range affected this stat directly. Since Repentance, most range affecting items affect the new range stat instead of tear height, and only a few items affect tear height directly. Tear height no longer majorly affects effective range.

### Items that Affect Tear Height

#### Notes

* Tear height adjustments occur in the order of the above list from top to bottom.
* Tear height can not be lowered to below 5.0.
* Certain items still use tear height to calculate their effective range, these include ,  (only slightly), , , , , , 's burst tears, , , , and  (inverted, lower tear height improves range).
	+ As a result, items that lower tear height, even if they don't affect range, such as  and , can negatively affect the effective range of the above items.
	+ With below 10 tear height 's split tears will hit the ground immediately, being unable to deal damage.
* Tears that pass through  and 's egg tears don't get reduced tear falling speed, and as a result, effective range is increased.
	+ tears' range will increase instead of decrease in these cases.

## Knockback

**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,  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 separate 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.

# Collision Knockback

V
p

×
K
×

M
p

10
×

M
t

{\displaystyle \text{Collision Knockback} = \frac{V\_p \times K \times M\_p}{10 \times M\_t}}

# Momentum Knockback

{

M
p

×

(

V
p

K
)

M
p

M
t

−

K

M
t

,

if the tear is not Piercing

M
p

×

V
p

M
p

M
t

,

if the tear is Piercing

{\displaystyle \text{Momentum Knockback} = \begin{cases} M\_p \times \left\vert \frac{(V\_p + K)}{M\_p + M\_t} - \frac{K}{M\_t}\right\vert, & \text{if the tear is not Piercing} \\ \frac{M\_p \times V\_p}{M\_p + M\_t}, & \text{if the tear is Piercing} \end{cases}}

Where:

* 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:

# Laser Knockback

{

1.8
×

M
p

M
t

,

if the knockback multiplier is not active

3.6
×

M
p

M
t

,

if the knockback multiplier is active

{\displaystyle \text{Laser Knockback} = \begin{cases} 1.8 \times \frac{M\_p}{M\_t}, & \text{if the knockback multiplier is not active} \\ 3.6 \times \frac{M\_p}{M\_t}, & \text{if the knockback multiplier is active} \end{cases}}

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.  or  decrease the tear mass, thus weakening the knockback.

### Items that Affect Tear Knockback

#### Notes

* 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 , , , , and  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

 The Bean | 5.100.111
 The Poop | 5.100.36

#### Notes

* There is also a mechanic that acts as an opposite of sorts to circular knockback: a gravitational pull that is emitted from Gaping Maws, Mega Fatty (while charging up its "Vomit Storm" attack), purple champion monsters, , and  Suction Pitfalls.