Combine Elite

Overview
Elites are heavier, less common, higher class Combine troopers that are essentially upgrades to the default Soldiers, sporting tougher armor, better proficiency, and better weapons. They are generally only deployed in important high security areas such as Nova Prospekt and the Citadel.

Elites are able to take more abuse than most other Combine ground units and are generally more accurate. They are also the only Combine humanoids capable of using the secondary fire on their weapons (AR2's energy ball launcher, OICW's grenade launcher, etc.), essentially allowing them to inflict higher damage than almost any other humanoid Combine unit.

Behavior
Elites behave similarly to the default Soldier, but generally start a firefight with a quick energy ball or grenade launched from their weapons, softening them up for their allies. Otherwise, they are often found skulking around their posts, searching for any enemies that may be intruding, if they aren't casually standing idle.

Interestingly, if their equipped weapon doesn't have a secondary attack, or their secondary simply isn't valid, Elites will attempt to charge it up and fire it anyway, leaving them vulnerable.

Tactics
-Listen carefully if you see an Elite. If you can hear a weapon charging up, such as the AR2, immediately dispatch them or get to cover; this indicates they are about to fire a secondary attack from their weapons.

-If you know an Elite is equipped with a weapon with an invalid or non-existent secondary attack, such as the Grease Gun, allow them to charge up. They are attempting to charge a weapon that cannot fire with a secondary attack, and as a result, they are simply wasting their time and leaving themselves vulnerable. However, do note that this is fairly rare to see, as most Elites spawn with either an OICW or AR2.

-Be careful with taking on Elites at a distance, as they can sometimes be freakishly precise with their weapons, landing repeated headshots on the player. This is most noticeable, and most common, on the higher difficulty levels.