Ablation

Ablation is a type of defense that functions similar to Shields, introduced with the Umbra faction, and occupies the same health bar slot. Ablation is provided by Ablative Armor, giving the benefactor a dynamic health pool (represented by Ablative Health) that regenerates whenever enough damage is dealt to enemies, even after complete depletion.

Explanation
Ablative Health is restored according to the Ablative Recovery statistic every time a cumulative amount of damage equal to the Damage Threshold is dealt. Some Ablative Recovery values are specific to damage type, which separately grants you Ablative Recovery, subject to the same threshold amount for that damage type.

You should try to maximize your Ablative Recovery to Damage Threshold ratio, which is how much Ablative Health you recover per point of damage dealt to enemy health. The higher this ratio, the more effective you can regenerate ablative armor.

Other than dealing damage, Ablative Health can also be restored whenever an enemy is destroyed within maximum range. Devour Recovery defines the proportion of the total Ablative Health that is restored in this case.

More details can be found below.

Ablative Recovery
Only damage to health (not shields, ablative armor nor screens) is counted towards the threshold. Do note that this takes damage resistance into account, so enemies with high resistances may diminish the effect of Ablative Recovery. In addition, only damage dealt to a ship or powered module is counted (exception: damage done to Altairian Pylon Emitters is never countered). Damage dealt by other ships does not count towards a particular ship's Ablative Recovery.

Damage dealt is accumulative: even if each individual shot does not meet the threshold, recovery will still activate when the total damage reaches the threshold. This also applies to damage in excess of the threshold. If damage dealt is multiple times the threshold, recovery is also multiplied by the same amount.

More specifically, the game checks for accumulated damage dealt against the damage threshold every tick. If accumulated damage is greater than the threshold, it will be reduced to, with the recovery amount being. Separate counters exist for Ablative Recovery concerning specific damage types, which only accumulate when damage of that type is dealt.

Both the recovery amount and damage threshold are stacked additively on a per-item basis. For example, 2x Ablative Tungsten Armor I + 3x Thonian Armor II gives (75 + 75 + 30 + 30) Recovery per (25 + 25) Damage Dealt = 210 Recovery per 50 Damage Dealt, and an additional (15 + 15) Recovery per (25 + 25) Blight Damage = 30 Recovery per 50 Blight Damage Dealt.

Devour Recovery
Devour Recovery activates whenever an enemy ship or module (not squadron) is destroyed within maximum range (regardless of firing arc and minimum range). The enemy need not be destroyed by that particular ship; in fact, all friendly ships with the destroyed enemy in range will have their Devour Recovery activated.

The amount of Devour Recovery gained stacks additively on a per-item basis, meaning that 3x Ablative Tungsten Armor and 1x Magnetic Collar III grants 5% + 5% + 5% + 10% = 25% Devour Recovery on a ship, i.e. 25% of the ship's Ablative Armor will be restored on activation.

Implications
Dealing damage to enemies is your primary method of recovering Ablative Health. Since only damage to health is counted, your recovery will initially be negligible (unless you have a way of bypassing enemy defenses), but once the enemy's defenses are depleted, your ablative armor becomes all but impossible to take down in a 1v1.

Devour Recovery is especially effective against enemies that use spawners, since each spawned ship that is destroyed allows you to quickly regain Ablative Health.

Trivia

 * Originally, Ablative Armor could be recovered from damaging unpowered modules. It is unclear when that was changed.