They are equipped with M-15 Vindicator battle rifles that can be armed with Disruptor Ammo. They can cause a lot of damage on a player and are capable of quickly stripping any defense away. They are also highly accurate troops that rarely miss a burst.
They possess shielding which increases in durability depending on the difficulty setting. They can regenerate their shields if given enough time after they are taken down. They are equipped with Tech Armor.
- The Legionnaire's biggest weakness is their weapon's burst-fire requirement—while capable of serious damage, they cannot keep a squad pinned down as effectively as a Heavy or Trooper. This will allow a player to coordinate a squad’s firepower and power usage on them more effectively, since they are defenseless while they wait for the slight delay in their weapons fire rate.
- A player equipped with weapons that keep up a constant stream of fire will easily suppress and damage Legionnaires. On harder difficulty levels they can cause very high amounts of damage; making suppressing them an unrealistic option, particularly if they are being supported by other troops. In this scenario, picking off the weaker opponents while utilizing powers on the Legionnaires is an effective strategy.
- In close-quarters combat they are capable of causing higher amounts of damage which can be problematic if they still have shields. Directing a squad's powers against them while also barraging them with gunfire is an efficient solution.