Half-Life 2/Allies and enemies

Metrocop

 * Weapons: Stunstick (10 damage), 9mm Pistol(3 damage), SMG (3 damage)
 * Accuracy: Medium (Stunstick), Medium (Pistol), Low (SMG)
 * Special attacks: Certain officers may deploy Manhacks.
 * HP: 25 in early chapters, 40 in late chapters
 * AI difficulty: Low/Medium

CP officers are the first human enemies you will face. Being police units instead of military, they are not equipped with very strong armor or weapons, and are usually poorly trained. They are seen brutalizing the citizens of City 17 in early chapters, and they provide the first ranged weapon for the player (a 9mm pistol). CP officers can be divided into 3 categories; stunstick, pistol, and SMG. Stunstick-armed officers will charge the player and attempt to beat them to death, and are the easiest to kill. Pistol-armed officers have mediocre accuracy but will maintain their distance, and SMG officers will tend to fight at medium to close range. All CP officers have relatively poor tactical AI (an intentional design choice to differentiate them from soldiers).

Overwatch Soldier

 * Weapons: SMG (3 damage), Pulse Rifle (3 damage), Shotgun (3 damage/pellet)
 * Accuracy: Low (SMG), Medium (Shotgun), High (Pulse Rifle)
 * Special Attacks: Will do a 10-damage weapon butt attack at point blank. Can throw a 75-damage grenade.
 * HP: 50
 * AI difficulty: Medium-high

Overwatch Soldiers are the Combine's military units. They are cybernetically-augmented transhuman infantry, and are equipped with more powerful weapons and armor than Metrocops. Soldiers are unique in that they work in squads, using advanced tactical procedures to defeat the player in combat. They are usually seen in more remote areas, such as the outlands and the wastelands, and also show up in the city during the Uprising. Soldiers' accuracy is determined by their weapon; while SMG-armed soldiers have terrible accuracy, their rate of fire is very high. Pulse Rifle-armed soldiers will hang back and exploit their weapon's accuracy against you. Shotgun soldiers have a unique brown and orange uniform instead of blue and white, and will fight at close range with their powerful shotgun. It is best to use the Pulse Rifle against soldiers; the SMG is still a useful gun, but can take many shots to kill a soldier. They also appear in the Nova Prospekt prison, where they have unique, darker-colored prison guard uniforms.

Overwatch Elite

 * Weapons: Pulse Rifle (3 damage)
 * Accuracy: Very High (Pulse Rifle)
 * Special Attacks: Will do a 15-damage weapon butt attack at point blank. Can launch a 15 damage energy ball that is an instant kill to any NPCs with the exception of vital allies (Alyx and Barney)
 * HP: 70
 * AI difficulty: Medium-high

Overwatch Elites are the deadliest Combine soldiers unit one will face. They are heavily-armored and equipped with the accurate Pulse Rifle, and can use its underslung energy-ball launcher, which can vaporize NPCs instantly. They have 70 health, meaning that using the SMG against them will take many bullets to dispatch them. Once again, it's best to use the Pulse Rifle. Notably, they never use the SMG or shotgun, and when they do appear in Nova Prospekt they have the same uniform as normal. They usually lead squads of regular soldiers, Hunters or fight in their own Elite teams.