Darkness

Darkness is a debuff. The player character takes increasingly high damage over time when outside of any lit areas in the form of a stacking debuff. The debuff deals damage equal to 2% of the player's life and energy shield per second,[confirmation needed because of 3.5.0 change] gaining a stack every 0.25 seconds (maximum 5000 stacks). Stepping into a lit area clears the debuff. Allied minions and totems will not take darkness damage. Additionally, monsters within the darkness cannot be damaged.

Light is primarily emitted by the Crawler, cables that are generated in cleared paths, and Flares. Flares are consumable items that can be thrown the create a temporary lit area. Its radius, duration, and maximum capacity can be upgraded with Azurite. Stalkers, a monster found in Delves, can temporarily disable sources of light.

The player's resistance to darkness damage and light radius decreases when delving deeper in the mine. Darkness resistance and light radius can be upgraded with Azurite.

Generic light radius modifiers will not work in the Azurite Mine.

Mechanics

Damage

Darkness stacks every 0.25 seconds up to a maximum of 5000 stacks. Each stack deals 2% of your eHP per second.[confirmation needed because of 3.5.0 change] (0.5% at 75% darkness resistance). Without any mitigation or regeneration you will die in darkness at 20 stacks (5 seconds). First second you will miss 5% ehp, then - 18%, 39%, 68% and 105% at the 5 second.

At 0% of the darkness resistance if regeneration applied to Life pool it will produce (1 / 1516) of degen per stack. The cap will be at 1516 darkness stacks with 1 eHP so.

If regeneration is applied to energy shield instead, the degen will produce (ES / eHP / 1516) of degen per stack. The cap will be at 1137 stacks with 4 eHP (3 ES) character.

Note: the new hidden degen cannot be mitigated by any % life regen. But (as well as the main Darkness damage) it can be mitigated by reduced damage taken over time modifiers (Arakaali's pantheon, crafted mod Upgraded (unlocked from Corruption Chamber or its upgraded variant) or legacy crafted mod of Suturing from old Leo); by Mind Over Matter keystone (*1,3) and Kintsugi body armour (*1,25).

In order to calculate number of stacks which you can handle with your regeneration use formula: "maximum stacks = (all the mitigations) * regeneration * 50 / eHP "