Damage/Corrosive Damage


 * Not to be confused with Corrosive Projection.

 Damage is one of the six secondary elemental damage types, composed of and  damage. It is immensely useful against most Grineer troops and heavyweight Infested creatures, but fares poorly against the Proto Shields of some Elite Corpus enemies.

Corrosive damage's unique status effect is Corrosion, which permanently degrades the target's current armor by 25%. The damage of the corroding shot is applied after the proc reduces the armor. 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 at an exponentially decreasing rate. 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. The enemy corroded by the proc will be covered in a green, electricity-like substance.

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.

Mods
†Denotes a source of corrosive damage that does not inflict the status effect on enemies.

Multiple Corrosion Procs
Because procs reduce the armor of an enemy by 25% of their current armor, each proc against an enemy removes less armor points than its previous proc, and (if not for rounding) would theoretically never reduce armor to 0. The number of procs it takes to get down to below 1 depends on the initial armor value of the enemy. For the following examples, keep in mind these colored benchmarks:



The background colors of the above table mark 10% damage reduction increments. As procs are inflicted 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, a weapon with both high Status Chance and high Fire Rate would be best.

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.

Bugs
Since, procs (FX and icon) permanently linger on enemies. This has no effect aside from affecting Condition Overload.