Originally issued to the salarianSTG to allow small units to contain much larger enemy forces, the Scorpion pistol now sees service galaxy-wide. It fires low-velocity, squash-head projectiles with a dual use. The high-explosive filler within the projectiles contains an adhesive that secures the projectile to the target on impact. When fired into a surface, it turns into a proximity mine.
With practice, the Scorpion can be paired with biotics for unorthodox (but highly amusing) tactics. A player can shoot an enemy with the Scorpion and then use Throw or Pull to guide them into nearby groups of enemies to take full advantage of the Scorpion's splash damage. Alternatively, one can catch a group of enemies in a Singularity and then fire upon them with the Scorpion without having to worry about missing.
The Scorpion can be very effective against Ravagers. In Bronze difficulty, 4 shots—whether on contact or as proximity mine—can easily kill a Ravager and the Swarmers it releases.
Used in tandem with a Cryo Ammo equipped M-37 Falcon, a team can snap freeze and paint multiple unarmored targets at a time with explosives and cause significant damage to or destroy outright groups of unarmored Cannibals, Cerberus Assault Troopers, and Geth Troopers. It is a very useful crowd control tool when faced with multiple targets, as it slows down the pace of the battle in your favor.
The Scorpion is very effective when combined with the Tactical Cloak of an Infiltrator who wants to use offensive powers regularly, such as the Salarian Infiltrator with Energy Drain. The damage of the Scorpion projectiles is only done when they detonate and Tactical Cloak is only broken when they are fired, so by firing them all onto a large target such as a Geth Prime and then going into Tactical Cloak allows for the damage bonus of Tactical Cloak to be applied to all of them.
When firing the last round in a magazine whilst in Tactical Cloak, the Tactical Cloak will not be lost. This appears to be a bug.
This weapon is favorable for classes (turians, batarians, krogan) that lack the ability to dodge, as it will always stagger enemy units near the explosion. Fire at the ground in front of you to take advantage of the slugs' Proximity Mine-like characteristics—this will stop Phantoms as they close in on you, giving you a few crucial seconds to escape their instant-kill grasp.
In this respect, this weapon can, if mastered, be the perfect choice for a Turian Sentinel. Also, this class' capability to use Overload can be devastating combined with the Scorpion, or any "electrical" tech power (e.g. Energy Drain, Electric Slash). After shooting a target with a few Scorpion explosives, quickly use Overload to turn the enemy into a walking bomb; all of the explosives detonate simultaneously or in quick succession, making short work of most unarmored enemies. This tactic also works when placing Scorpion projectiles on surfaces, such as floors or walls. Overload an enemy near the projectiles, and create an explosive field.
Classes with Proximity Mine can use it to great effect in tandem with a Scorpion. If the mine is fired at a group of enemies it will stagger them, allowing the Scorpion's projectiles to do damage to a large number of foes. If the Rank 5 Damage Taken evolution is taken, all the enemies caught in the blast will take a large amount of damage. Try using Proximity Mine, firing the Scorpion several times during the cooldown, then use Proximity Mine again. This process can keep a large number of enemies off-balance while you whittle them down quickly. On certain maps one can defend an entire flank alone with this strategy.