History of Surge

Overview

Surge is an activity modifier in Destiny 2. An elemental Surge gives a 25% damage bonus when you use weapons or abilities of the matching element, so players are expected to bring matching loadouts (per Sportskeeda). Raids and Dungeons had a weekly rotating elemental Surge before Bungie announced their removal from those activities.

In the Portal, Surge modifiers can be enabled under Boon and Event Modifiers on Expert difficulty or higher.

Anti-Surge

Anti-Surge is a challenge modifier that can be enabled in the Challenge Modifiers section of Portal activity customization on Ultimate difficulty.

Not to be confused with

Surge Protector is a triumph relating to the Surging state in Eruption in the Crucible, a separate mechanic.

Sources do not give exact Anti-Surge numbers.