Sentry Gun

“

How am I going to stop some big mean mother hubbard from tearing me a structurally superfluous new behind? The answer: use a gun. And if that don't work... use more gun. — The Engineer

”

The Sentry Gun (sometimes known as a "Turret", "Sentry" or abbreviated to "SG") is a building that can be constructed by an Engineer and functions as an automated turret which fires upon any enemy who walks into its line of sight. The Sentry Gun will always target and fire on the closest enemy player or building, provided they are within firing range and in line of sight of the Sentry (not behind a wall, etc).

The Sentry Gun costs 130 Metal to build, 200 Metal to upgrade to level two, and an additional 200 to upgrade to the third and final level. With each upgrade level the Sentry Gun becomes more powerful, gaining machine guns, rockets and the ability to take more damage. The firing range remains constant regardless of level.

The Sentry Gun's ammo may be replenished with your own metal by hitting it with your Wrench. Each bullet reloaded costs 1 metal and each rocket salvo costs 2 metal.

When placing a Sentry Gun, the limit of its range is represented by a 3D sphere of your team color. A Sentry that is being constructed will have its health increase gradually until it reaches its maximum health upon completion. The Sentry rotates 90 degrees to patrol the area, but is capable of rotating 360 degrees to lock on to a target. This takes a brief moment however, which may allow faster foes to slip past its range. The Sentry can also be manually rotated to face a different direction before you build it: When the blueprint is shown, using the alternate fire button (default key: MOUSE2) will rotate the blueprints clockwise by 90 degrees.

Sentry Guns will not fire upon enemy Spies that are cloaked or disguised. Sentry Guns are also unable to fire if an enemy Spy attaches an Electro sapper to it or while they are being upgraded/built. A destroyed Sentry Gun leaves 60 Metal worth of pieces, which can also be picked up by other classes as Ammo.

Unlike most other weapons, the sentry gun's weapons do not get affected with damage falloff from range nor can it gain criticals. It is possible however, to make the Sentry Gun deal Mini crit attacks and damage if its target is coated in Jarate or if the Engineer who built the sentry is close to a Soldier with an active Buff banner, boosting the damage of each bullet to 22.

Sentry Gun Levels

Level	Kill Icon	Health	Cost	Weaponry	Damage	Ammo
1		150	130 Metal	Semi-Automatic Firing Barrel	14-18 damage 4 shots per second 64 average DPS	100 bullets
2		180	330 Metal	Dual Rotational Minigun Barrels	14-18 damage 8 shots per second 128 average DPS	120 bullets
3		216	530 Metal	Dual Rotational Minigun Barrels Target Guided Rocket Launch Support System	14-18 damage (bullets), 8 shots per second for 128 average DPS Rockets fire every 3 seconds dealing 100 damage on direct hit	144 Bullets 20 rocket salvos

Trivia

Modifying your Sentry

• The Engineer apparently designed and built the Sentry Gun under contract from 'TF Industries' in 1965.
• The official game manual for Team Fortress 2 is actually the Sentry Gun Operating Manual.
• Engineers can receive a "Sentry Gunner" achievement for racking up 10 kills with a single Sentry Gun; the Engineer can die, as long as the Sentry Gun does not.
• A label on the Sentry Gun blueprint reads "Automatic Sentry Aperatus;" however, the Sentry Gun manual refers to it as a "Sentry Mechanical Firing Device".
• Like all Buildings, Sentry Guns can be built underwater.
• Sentry Guns cannot fire through a Dispenser built by an Engineer of the same team.
• The Sentry Gun makes a number of beeps every time it reverses its rotation. The number of beeps corresponds to its upgrade level, where a level 3 turret makes three quick beeps. Additionally, the higher the Sentry's level, the louder it is. A level 1 sentry is slightly harder to hear than a level 3 Sentry; this fact can be used to counter enemy Sentry Guns.
• When out of ammunition, a Sentry Gun will continue lock on to enemies and attempt to fire, but will instead make clicking sounds.
• Engineers can reach higher standing on a level 1 Sentry Gun than with a Dispenser, making it a better choice on jump and puzzle maps.
• Due to a bug, the rockets from a Sentry Gun may sometimes damage teammates if the sentry gun is destroyed as the rockets are in-flight.
• An unused alternate kill icon for the level 1 Sentry Gun exists in the game files, seen to the right.

Unused level 1 sentry kill icon

External links

• Sentry gun manual