Slag



 is an element introduced in Borderlands 2, created as a by-product of refining Eridium. Slag elemental weapons have a chance to coat enemies in slag. Slagged targets take doubled damage from all non-slag sources.

Effectiveness
Slag damage has no bonuses or penalties against any type of target. Once a target is slagged, any non-slag damage that target suffers is doubled, including effects from elemental affinities, critical hits, and damage over time.

The slag-coating effect lasts 8 seconds on normal enemies. However, bosses tend to have Slag resistance that reduces the duration of the Slag effect. Raid bosses such as Terramorphous have such high resistance that the Slag effect typically lasts only a fraction of a second in Normal or TVHM.

In Ultimate Vault Hunter Mode, Slag effects are boosted to last longer and cause triple damage (+200%) from non-slag sources. Even damage from slag sources will enjoy a +50% bonus.

Story Involvement
In the Wildlife Exploitation Preserve, Handsome Jack has ordered for tests to be done to determine the effects of slag on animals.