Explosive Pact is an origin trait in Destiny 2 that can appear on 1 weapon. An enhanced version exists on crafted and some newer weapons.
What Explosive Pact does
This weapon gains bonus stability and reload speed when activating a grenade ability. Healing grenades and grenade final blows grant additional stacks of the bonus.
Enhanced version
This weapon gains an improved amount of stability and reload speed when activating a grenade ability. Healing grenades and grenade final blows grant additional stacks of the bonus.
