History of Overshield

An Overshield is a temporary protective layer added on top of a Guardian's normal health and shields; it absorbs incoming damage before those layers. The Destiny 2 Void 3.0 update also states that Void Overshields reduce damage from PvE combatants. Overshields can come from different abilities and gear effects; in the historical Gambit Prime example, Collector's Umbral Armor granted one when collecting Motes.