Not to be confused with the first game's version, The Back-up.
The Back-Up is a returning Equipment in Risk of Rain 2. It is unlocked by completing the Mechanic Challenge.
Activating this item summons four attack-drones to the players aid. After 25 seconds, these drones expire and blow up. The cooldown from activation is 100 seconds.
As the drones fight without any input from the player and draw aggro from enemies, this item can be used to gain some peace and money without engaging in combat.
This item is the best way to notice the extra activations from the Gesture of the Drowned, as sometimes eight, twelve, or even sixteen drones can appear.