Damage/Corrosive Damage


 * Not to be confused with Corrosive Projection.

Corrosive Damage is a combined elemental damage type consisting of Electric and Toxin damage.

Corrosive damage's unique status effect is Corrosion, which permanently degrades the target's current armor by 25%, causing affected armored units to be more vulnerable to subsequent damage of any type. Corrosion can be applied multiple times to the same target, with each following proc reducing the remaining armor by another 25% of its current (not the initial) value, thereby causing the target's armor to decay logarithmically. When the target's armor value falls below 1, it is rounded down, and the unit loses its armor type with all its damage type modifiers, which is indicated by the unit's health bar turning from orange (armored) to red (unarmored) and a change in sound effects on hit. Against unarmored enemies, the status effect is useless. Against Tenno, the status effect lasts for 8 seconds.

In the case of shots with multiple pellets (both by default and through multishot mods), multiple stacks of Corrosion can be applied in the same shot. For this reason, the corrosive status chance per shot is not as meaningful as the corrosive status expected value per shot. See Status Effect for more info.

Corrosive effects do not remove hard invulnerability effects, such as the special protection possessed during the first half of the fight with Lieutenant Lech Kril. Additionally, a few bosses (notably Vay Hek), seem to be immune to heavy Corrosion-stacking.

Innate Corrosive Weapons

 * Stug
 * Tysis

Misc. Corrosive Sources

 * Purity effect
 * Saryn: Miasma

Type Effectiveness
Grineer =
 * -|Corpus =
 * -|Infested =

Multiple Corrosion Procs
procs reduce the armor of an enemy by 25% of their current armor. This means that each proc against the same enemy removes somewhat less armor than the previous proc, and if it weren't for rounding, you could theoretically never reduce them to 0. Armor itself increases the amount of damage reduction by less per point for each point the unit has, so as you continue to proc against a heavily armored enemy, you actually remove more damage reduction per proc on the enemy. The number of procs it takes to get down there depends on the armor value of the enemy. For the following examples, keep in mind these benchmarks when you look at the list:



The background colors of the above table mark 10% damage reduction increments. As you inflict procs against the following hypothetical enemies, they will be brought lower and lower down the rainbow spectrum in damage reduction. The way the remaining armor is calculated is an exponential function as follows:


 * Initial Armor is the original armor of your enemy.
 * Procs is the number of times that procs occur on the enemy.



Were this chart to fill in the gaps and continue, the trend would reveal that every 8 procs reduces the armor value of the current target by almost exactly 90%. This means for players fighting high level Grineer enemies (for reference, a level 120 Heavy Gunner has roughly 10000 armor), procs are nearly essential to kill them, and to get a sufficient number of procs on the enemy, you might need to use a weapon with both high Status Chance and high Fire Rate.

Complete Armor Depletion
The complete removal of a target's armor occurs when its armor value falls below 1. This may be desirable to remove the damage type modifiers of the target's armor type, or it may be unwanted in the case of Corrosive damage against Ferrite armor, as this means losing the +75% damage bonus. Either way, it is important to consider when this event is expected to occur.

Based on the previous equation describing the relationship between number of procs, initial armor and remaining armor, one can calculate for any given armor value the number of procs required to deplete it completely:



Conversely, one can calculate for any given number of procs the greatest armor value which it can deplete completely:



The bottom line of this for fighting armored targets with Corrosion effects is that, since the number of shots required to deplete the target's armor grows slower with enemy level than the number of shots required to deplete the target's health, armor depletion will occur more often and already at higher relative amounts of health left as enemy level increases, for any fixed weapon setup which can proc Corrosion.