Slag only exists in Borderlands 2 and deals full damage to Flesh, Shielded and Armored Enemies. It is the only element in Borderlands 2 that doesn't deal damage over time.
Slag Weapons generally have a 1.5 times higher elemental effect chance, than other elements.
Normal / True Vault Hunter Mode: The Slag Debuff lasts for 8 seconds and doubles all non-Slag damage. (including Melee Damage, other elemental damage, critical hits and damage over time effects)
Ultimate Vault Hunter Mode: The Slag Debuff lasts for 15 seconds and triples all non Slag damage, while also boosting Slag Damage by 50%.
- Slag Enemies can't be Slagged and are resistant to it.
- Enemies that are immune to damage over time effects can't be slaged: Crystalisks, Constructors, The Leviathan, Jackenstein, Piston's Blimp, Badassasaurus, Saturn, Uranus
- Raid Bosses can only be slaged for 1 second, except Pyro Pete and Master Gee. They are slaged for the full 8 or 15 seconds. (depending on the game mode)