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Mass Effect Wiki

The Arc Projector is a heavy weapon in Mass Effect 2.


The arc projector ionizes targets with a nonvisible laser to ready them for a high-voltage electrical attack. As the lightning-like bolt hits its first target, a sophisticated autotargeting system paints succeeding targets with the ionization laser, allowing the electricity to take the path of least resistance and arc between them. An entire enemy strike team can be shocked to death with a few pulls of the trigger.


The Arc Projector is available as a downloadable content item if the Cerberus Network has been activated, and it can first be equipped once Shepard has been given command of the Normandy SR-2. In Mass Effect Legendary Edition it is part of the game by default with no DLC or activation of Cerberus Network being required, becoming available to the player at the same point.

E-Mail from the Illusive Man


We recently had an incident involving the geth at one of our outposts in the Skyllian Verge. Don't worry; I'm not sending you off to chase anything down. Our operatives waged a highly successful battle against a geth scouting party and credited their success to a new advanced electrical attack device that we finally let them take out of the lab. Since their unit is being reassigned for some rest and relaxation, I thought you should take custody of the weapon in the meantime.

The weapon is called an arc projector. I sent it to the Normandy's armory so you can examine it for yourself and use it if you deem it worthy. It's gone through plenty of tests that indicate it overloads kinetic barriers and synthetic enemies particularly well, but laboratory demonstrations are a poor substitute for actual field reports. We know it works. Now we want to see what it can do in the right hands. If all goes well, we'll use your tactics to train other operatives.

Player Notes

  • This weapon requires two seconds to charge up before firing. Attacks that stagger the player such as biotics, missile fire, and melee hits will interrupt the charge.
  • In contrast to most heavy weapons, the Arc Projector has limited range. A good rule of thumb is that it won't hit enemies engaging at sniper rifle-appropriate distances.
  • The Arc Projector deals heavy damage to shields (blue), moderate damage to armor (yellow) and barriers (purple), and the least damage to red health bars.
  • In addition to its damage bonuses against various protections, the Arc Projector deals approximately 20-30% more damage to synthetic (robotic) targets of all types.
  • The bolt tends to "find" the initial target as long as the crosshair is aimed in its general direction (precise aiming not required).
  • Chain Lightning: True to its name, hitting any nearby enemy will cause the bolt to "arc", or jump to another viable nearby target, be it another enemy or explosive object. The range of the chaining effect is fairly long and can hit most enemies within an average-sized room regardless of their positioning. Although the initial shot requires direct line-of-sight in order to hit a target, the chaining effect will often disregard cover regardless of the follow-up targets' positions as long as they are not totally obscured in a direct line of sight from the last target to be hit.
    • Enemies can't be hit more than once by a single shot.
    • The maximum number of targets hit is five.
    • The primary target hit takes maximum damage, and each subsequent enemy hit takes slightly less damage than the last.
    • The chaining effect does not occur if the primary target is an explosive or destructible object such as a gas tank.
    • Shots can chain to hit Geth Hunters even while they are cloaked and invisible.
    • Shots can chain to hit Collector Guardians hiding behind their deployable shields AND shots can pass through the shields to hit them directly if they are the primary target.
  • Secondary Effects: The Arc Projector carries with it almost all the effects of Overload, including the on-death detonation of mechs and pyros, stunning unprotected synthetics, and enhancing the explosive power of canisters. Each jump of the lightning also has a chance to put most bipedal organic enemies in a severe stun state where they spasm and then drop to the ground, similar to how Neural Shock works; unlike the power, this effect can work even on protected enemies. All organic enemies hit by the Arc Projector also have any health regeneration abilities permanently stopped—again, very much like the Neural Shock power.
    • The Arc Projector does not, however, overheat enemy weapons as Overload can when used on unprotected enemies.
    • The Arc Projector actually does its damage as very rapid damage-over-time, it isn't quite instantaneous. Most of the effects that only work on unprotected targets will usually affect targets as long as their protection (shields, barriers, or armor) breaks from a single shot, which the Arc Projector can usually do even on Insanity difficulty. Pyro-type enemies with flamethrowers can therefore be one-shotted due to the overloading of their fuel tanks.
    • Because most synthetic enemies will explode on death if killed by this weapon, be careful about killing them in very close proximity (melee range) as those explosions can injure and stun you. This is especially deadly to clustered mechs.
    • Interestingly, the "neural shock" effect against organic targets seems to always work against krogan enemies (Note: except when they are in their charging animation), when against most other organic foes this effect only triggers some of the time. The neural shock also does not occur at all on husk-type enemies, they are only briefly paused. Klixen are totally immune and are not even paused. Varren are frozen in place for several seconds before being able to move again. A Harbinger-possessed Collector is briefly stopped by the Arc Projector while advancing but never suffers the neural shock incapacitation; while firing its biotic attacks it can't be interrupted at all.
  • The Arc Projector does not cause any type of damage to Shepard or the squad directly, though as noted above, care should be taken around targeted synthetic enemies, flamethrower-wielding enemies, and explosive objects.
  • This weapon is good at slowing down groups of husks and stripping their armor if they have any but isn't particularly good at killing them especially on higher difficulties. Also, getting hit by melee attacks interrupts attempts to fire the weapon. The M-622 Avalanche, M-100 Grenade Launcher, and even the M-490 Blackstorm are more effective at mass husk-killing and more ammo-efficient as well.
  • The Arc Projector is riskier to use on on Hardcore and Insanity due to the 2 second charge-up delay before firing. On the higher difficulties 2 seconds taking enemy fire is often more than enough to be fatal and charging a shot forces you to poke out from cover if you are currently attached to any. The only way to compensate for this is to stand behind large cover without attaching to it and time the shot to fire the moment you poke out. Fortunately, the Arc Projector doesn't require precise aiming.


See Also