HECU Sentry Gun

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HECU Sentry Gun
Production information
Type	Autonomous gun platform
Affiliation	Hazardous Environment Combat Unit Black Ops
Technical specifications
Maximum ammunition	Infinite
Damage	3 (Per bullet)
Rate of fire	High
Game information
Entity name	monster_sentry

The Hazardous Environment Combat Unit Sentry Gun, commonly referred to as the HECU Sentry Gun, is a fully autonomous weapon featured in Half-Life and its expansions. Sentry Guns are commonly used by the HECU and Black Ops to guard chokepoints and vital areas. They share some aspects of their design with the newer model seen in the sequel, Half-Life 2, including a tripod base and a tall, narrow body.

Overview

The gun consists of a powerful machine gun built onto a tripod. The gun itself rests on a turntable mechanism of sorts on the top of the tripod, which allows it to rotate and fire in any direction, unlike the equivalent device in Half-Life 2, which has a narrow field of fire.

Gordon Freeman encounters a Sentry Gun for the first time in the chapter "We've Got Hostiles". These were used by the HECU to guard areas after their soldiers had passed through. Some of these guns rely upon an independent laser sensor to detect targets while others deploy automatically without the usage of a laser. Once a target has tripped the beam or has been detected automatically, touching a sentry, firing near a sentry (GoldSrc only) or damaging it, the turret deploys its weapon with a high pitched whine and fires upon any target in sight. Once activated, the sentry would remain alert for a time (it makes a steady beeping sound whilst scanning for targets) before sinking into a dormant but alert state. Despite appearing gawky and unstable, these guns are in fact stronger than they appear and are difficult to knock over. Any sufficient type of damage will knock them over but explosives are the most effective tactic.

A variant is encountered later on that has auto-arms when it detects motion. The PlayStation 2 port put a red light on these to indicate that they were motion-activated rather than sensor-activated.

Tactics

Sentry Guns are powerful enemies, but are severely limited in mobility. When encountering one, stepping back and considering tactics is advised, as unlike other enemies, this one does not move. Looking for a way around or using explosives is a good move.

Since Half-Life's GoldSrc engine lacks a robust physics system, Sentry Guns simply fall over once they've taken a set amount of damage. Sentry Guns can take a considerable amount of damage, so opt for hard-hitting attacks, like a well-placed Colt Python shot, a Shotgun double-blast, or explosives, like Grenades, Satchel Charges, or the RPG. Also, keep an eye out for their laser sensors; avoid tripping them, bypassing fighting the guns entirely. However, these tactics may change when playing Half-Life: Source because of the upgraded physics engine (although like their GoldSrc variants, they "die" when they take enough damage).

Trivia

• Unlike the Black Mesa counterpart, these Sentry Guns do not go into standby mode and retract into its body if there are no targets in range. The only way to disable the turret is use explosives or gunfire, as they do not have switches to deactivate them. However, in Half-Life: Source, it possible to disable these turrets by using console command "ent_fire monster_sentry deactivate".
• The HECU Sentry Gun shares its firing sounds with the MP5. In fact, if the Half-life: HD pack is installed, the M4 Carbine sounds are used for the sentry gun.

Gallery

Decay model.

List of appearances

• Half-Life: Day One (First appearance)
• Half-Life
• Half-Life: Opposing Force
• Half-Life: Blue Shift
• Half-Life: Decay