Emergency Systems Purge in 3... 2... 1... – When O2 is above 75, the next shot will consume 50 O2 and release a shockwave around the point of impact, knocking back enemies and dealing non-elemental damage. Restores 12 O2 upon killing an enemy.
Usage and description
In addition to its above-average stats, the Systems Purge's unique effect can be compared in many ways to an Amplify Shield, as its shockwave is centered on the chosen target and damages both the target and other nearby enemies. In addition to the damage caused, the shockwave can also be utilized as an effective method of crowd control.
Its effect uses a sizable portion of its oxygen capacity, making it difficult to use when in a vacuum, as its oxygen recovery cannot outmatch its oxygen consumption. However, it can be used nearly indefinitely when in an atmosphere, as all that can limit its use is the very brief depletion period before the atmosphere rapidly begins passively restocking its oxygen supply.
As Claptrap doesn't consume oxygen in a vacuum, it is able to utilize the System's Purge effect more easily than other Vault Hunters when not in an atmosphere.
The effect can be triggered multiple times if many projectiles struck a target simultaneously. This is most evident from shotguns as the effect stacks with each pellet, resulting in a much higher amount of bonus damage dealt.
However, it does not trigger with splash damage, which can make certain weapons who only deliver their damage as such not subject to this ability, such as all rocket launchers (except Kaneda's Laser, and Torgue shotguns.