ADVENT units are the most frequently encountered in the game - you will face them from the very beginning of the game. It's the typical cannon fodder of the alien army - the enemies are numerous, yet they can't do anything significant at their own.
ADVENT troops are divided into five types:
- Trooper - the most common ADVENT soldier, equipped with an assault rifle. Those units often try to flank your soldiers, even if that puts them in a vulnerable position. When they are in range of 2 or 3 tightly grouped soldiers, they almost always resort to using grenades.
- Officer - insignificantly more powerful version of the previous unit. Equipped with the same weaponry as the grunt of the aliens, but has access to the Mark ability, allowing him to mark one of your soldiers. All the ADVENT troops in the area will then focus fire on that very soldier, without any regard to their own safety.
- Stun Lancer - one of the most annoying units in the game. This soldier is equipped with a typical assault rifle, but the biggest threat comes from the sword that he is wielding. Similar to your Ranger soldiers, the Stun Lancer can run an extremely long distance (equaling to about 3-4 typical "moves" of your soldiers), after which he is able to perform a melee attack. The strike does serious damage and can either disorient, stun for a single round, or knock your soldier unconscious.
- Shieldbearer - a soldier almost identical to the Trooper, but having an ability that turns him into your priority target. He can cast a shield on himself and all his allies in the range of the ability, granting 3-5 points of bonus health. In order to quickly get rid of the shield, you just have to kill the enemy that used the ability - all the troops will then lose the shields.
- ADVENT Mec - basically a heavily armored soldier, bearing a striking resemblance to a typical mech. The enemy has the offensive capabilities of a typical Trooper, the only difference being the fact that he uses a rocket-like attack instead of throwing grenades. The enemy cannot hide behind covers, which turns him into an easy-to-hit target, but often comes with 2 points of armor, which should first be shredded if you want to quickly get rid of him.
The first two enemies appear from the first mission, whereas the rest come into action gradually, as you progress in the game. ADVENT troops are often dropped into the battlefield as reinforcements. You should eliminate them in the following order: Shieldbearer, Stun Lancer, Officer, ADVENT MEC, Trooper.