For the damage type, see Damage/Corrosive Damage.
Corrosive Projection is an aura mod that reduces armor for all enemies in a mission.


Rank Effect Cost *
0 -5% -2
1 -10% -3
2 -15% -4
3 -20% -5
4 -25% -6
5 -30% -7

* Aura mods increase the amount of Mod Capacity


  • This can be stacked with other teammates to reduce armor by up to 100%.
    • When stacked to 100%, the yellow health bars of armored enemies will turn red.
    • 4 Corrosive Projections are required for complete armor removal, or 3 if all are supported by Mod TT 20pxCoaction Drift.
    • Enemies that have had all their armor removed lose their armor type's resistances and weaknesses:
  • Has reduced effectiveness under the "Augmented Enemy Armor" Sortie condition.


Effect on Damage Output

The exact benefit gained by having a given number of CP (Corrosive Projection) auras in the squad depends on a multitude of factors. In general, the higher the enemy armor, the stronger the benefit of CP. Also, the more CPs in the squad, the stronger the benefit per CP. This unusual behavior originates from the fact that the armor reduction from multiple CPs stacks additively.

For up to three CPs, the relative benefit can be expressed as a function of both the number of CPs and the target's net armor, i.e. its base armor multiplied with its level scaling factor for its current level, armor mitigation from damage type modifiers against the target's armor type for the attacking damage type composition, and any buffs or debuffs — everything except the CP debuff. The function is:

Benefit ( #CP , Armor ) = #CP ÷ ( 10/3 − #CP + 1000/Armor )

The benefit converges against a limit as armor approaches infinity:

lim (Benefit) = 3 ÷ ( 10/#CP − 3 )
  Armor → ∞

This limit is 3/7 or ≈+42.86% for one CP, 3/2 or +150% for two CPs and 9 or +900% for three CPs.

For four CPs, the benefit is the difference between the ratio of the previous net armor damage divisor (and as such a linear function of the target's net armor) and the previous damage type modifier of the attacking damage type composition against the target's armor type, since this gets lost in the complete deletion of the target's armor:

Benefit4CP ( Armor, Type Modifier ) = ( 1 + Armor/300 ) / ( 1 + Type Modifier ) − 1

The type modifier used here is the total armor type modifier of the composition:

Type Modifier = ∑ ( BDtype × ( 1 + HMtype ) × ( 1 + AMtype ) ) ÷ ∑ types ( BDtype × ( 1 + HMtype ) ) − 1

For positive type modifiers, the benefit can be negative in the range of small armor values, meaning that the damage gain by the deletion of armor is being outweighed by the loss of the flat damage bonus from type modifiers. The root of the benefit function for 4 CPs is given by the equation:

Armorneutral = 300 × Type Modifier

Meaning that for armor values between zero and this value, the effect will be negative, and for armor values greater than this value, the effect will be positive. The largest possible type modifier is currently 0.75, and for this, the root is 225.

The linear function only shows the described properties for positive armor values. For 0 armor, the benefit is always 0, because this means the absence of armor type modifiers, and for negative armor, it is not defined.

For any non-positive type modifier (zero or smaller), the benefit of four CPs will always be greater than that of fewer CPs, and being a linear rather than a rational function, it does not converge against a limit, but instead keeps growing indefinitely. Therefore, even for strong positive type modifiers, 4 CPs will eventually surpass 3 CPs for sufficiently large net armor values. In fact, the net armor value for which 3 CPs and 4 CPs give an equal damage bonus is:

Armor3CP=4CP = 3,000 × Type Modifier

For all armor values greater than this threshold, four Corrosive Projections provide a greater benefit.

CP Bonus

The damage bonus from any number of Corrosive Projections as a function of the target's net armor, i.e. after damage type modifiers and buffs/debuffs have been taken into account. The horizontal lines mark the limits against which the respective curves converge, in the case of 1 to 3 CPs. The range of possible values for 4 CPs is displayed by an exemplary family of functions that cover the range of possible type modifiers.


  • Corrosive Projection was originally obtainable during Artifact Defense Event from special alerts, and is now available to be bought with Creds from Nightwave Offerings.
  • Prior to Damage 2.0, if all 4 players in a given cell each used a fully-ranked Corrosive Projection, this would result in negative armor values and all damage dealt by the cell would be reduced to 1. This was fixed by capping the maximum armor reduction to 100%.
  • As with Mod TT 20pxEnemy Sense, the mod card still depicts a Shield Lancer armed with a Sicarus Sicarus.


Patch History

Update 25.1
  • Fixed enemies spawning being uneffected by Corrosive Projection Aura worn by players in the Rift at the time.

Update 8.0

  • Introduced as part of the Artifact Defense Event.

See also

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