From Team Fortress Wiki

“ more gun.

The Engineer (Meet the Engineer) 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... usegun. ”

The Sentry Gun (abbreviated to SG), also known as the Sentry Mechanical Firing Device, Sentry, or Turret, is a building that can be constructed by the Engineer using the PDA, the Engineer's build tool. The gun itself is a tripodal device constructed of metal, team-colored paint, and a laser sight (when used with the Wrangler).

The Sentry Gun functions as an automated turret that fires at the closest enemy within its range and line of sight. Dealing constant as well as consistent damage with noticeable knockback and an immunity to critical hits, a Sentry Gun is the cornerstone of a successful defensive setup. On the other hand, they take a while to set up to full potential, and even a fully-stocked Sentry Gun can be destroyed with little trouble by a well-executed ÜberCharge or a Spy with his Sapper. Engineers must be on the lookout for such threats to ensure their Sentry Gun's survival.

Functionality

The Sentry Gun costs 130 Metal to build, 200 Metal to upgrade to Level 2, and an additional 200 to upgrade to the third and final level totaling to 530 Metal. With each upgrade level, the Sentry Gun becomes more powerful, gaining machine guns, rockets, as well as more health. The firing range remains constant regardless of level. The Sentry Gun's Ammo and Health may be replenished with Metal by the Engineer hitting it with his Wrench. Each bullet reloaded costs 1 Metal and each rocket reloaded costs 2 Metal.

When placing a Sentry Gun, the Engineer can see the limit of its range represented by a 3D sphere of the team color with a radius of 1100 Hammer units. A Sentry Gun that is being constructed will have its health increase gradually until it reaches its maximum health upon completion. While automatically scanning, the Sentry Gun rotates 90 degrees about the direction it is pointing, is capable of detecting and rotating the full 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 Gun can also be manually rotated when placing to face a different direction before building commences. When the blueprint is shown, using the alternate fire button (default key: MOUSE2) will rotate the blueprints counter-clockwise by 90 degrees.

Sentry Guns are damaged by most weapon effects that damage players, however, some a few effects are modified for Sentry Guns. Also, weapon damage done to a Sentry Gun does not suffer from range falloff, with the exception of any scatter based weapon. A destroyed Sentry Gun drops 65 Metal worth of scrap pieces, which can also be picked up by other classes as Ammo.

As do other Buildings, Sentry Guns emit sound cues to alert players to their presence and status. A scanning Sentry Gun makes a number of beeps every time it reverses its rotation (1, 2 3) — the number of beeps corresponds to its upgrade level, where a Level 3 turret makes three quick beeps. Additionally, this beeping increases somewhat in volume with Level 2 then Level 3 Sentry Gun's level; so, the higher the level, the farther away the Sentry Gun can be heard; this fact can help attentive players find guarded areas. The Sentry Gun's scanning noise sounds slightly different when being fired on by the enemy; slight clicks can be heard along with the regular beeps. The scanning Sentry Gun also makes a distinctive noise when it detects and locks onto an enemy target just before firing — this noise both alerts the enemy of the detection by the Sentry Gun and the team of the presence of enemy within the range of the Sentry Gun. If an enemy Sentry Gun detects you, you will hear its noise as a slightly different alert noise. All of these scanning noises are silenced when a Sentry Gun is Wrangled.

Sentry Guns will not fire upon enemy Spies that are cloaked. In general, Sentry Guns will not fire upon enemy Spies that are disguised; however, if the Sentry was firing upon the Spy at the time the disguise was activated, the Sentry will continue to fire upon the Spy until the Spy cloaks, breaks line of sight, or moves out of range. Sentry Guns will also not fire upon enemies in its range if there is a water surface between them or if the enemy is behind cover – this cover includes the Engineer's Dispenser. Sentry Guns are also unable to fire if an enemy Spy attaches a Sapper to it or while they are being upgraded/built. Feign deaths produced by the Dead Ringer are not added to the Sentry Gun kill/assist counter, but do contribute to the Best Little Slaughterhouse in Texas achievement.

Unlike most other weapons, the Sentry Gun's weapons do not gain criticals. It is possible, however, to make the Sentry Gun deal mini-crit attacks and damage if its target is coated in Jarate, under the effects of the Fan O'War, or if the Engineer who built the Sentry Gun is close to a Soldier with an active Buff Banner – boosting the damage of each bullet to 22.

Included in the Engineer Update is an unlockable secondary replacement, the Wrangler, which allows the Engineer to take direct control of his Sentry Gun by "marking" targets manually. Doing so shuts down the Sentry Gun's automated target-lock system, but diverts the excess power from the targeting system into speeding up its firing rate, effectively doubling the damage-per-second of the Sentry Gun. The Wrangler also provides the Sentry Gun with a protective shield which absorbs two-thirds of enemy fire while the Wrangler is active. A wrangled Sentry Gun has no maximum range, though its accuracy slightly decreases at longer ranges and its knockback force is halved against targets outside of its normal reach. Once the Engineer switches away from the Wrangler, however, his Sentry Gun is unable to fire for 3 seconds while its auto-lock targeting computer reboots. It is still shielded during this time.

Since the Engineer Update, players are able to haul their buildings around. An Engineer carrying his Sentry Gun moves 10% slower and cannot fire or change weapons. However, a redeployed Sentry Gun retains its previous level and automatically sets up twice as fast. Engineers do not lose any Ammo or Metal by moving Sentry Guns (unless the Sentry Gun was picked up with the Rescue Ranger's alt-fire, which costs 100 metal for a Sentry Gun or a Combat Mini-Sentry Gun). If the Engineer is killed while hauling his Sentry Gun, it is automatically destroyed along with him and gives a notification in the kill icon area of the screen. Sentry Guns under the effects of a Sapper cannot be picked up.

An Engineer is vulnerable to damage from his own Sentry Gun's bullets. For about the first 300 Hammer units of their flight, Sentry Gun rockets will pass through the Sentry Gun's Engineer without detonating as if he were another member of the same team. However, if the rockets do strike another surface within this distance and explode, the Engineer is vulnerable to the resulting splash damage. Beyond this initial distance, the Engineer is fully vulnerable to his own Sentry Gun's rockets. (The knockback from Sentry Gun self-damage enables the Engineer to perform bullet and Sentry rocket jumps, especially with the aid of the Wrangler.)

In Mann vs. Machine mode, Sentry Guns can gain benefits from certain Power Up Canteens their owners use. An ÜberCharge Canteen will form a Wrangler-esque shield around the Sentry Gun, fully protecting it from attacks. Use of a Kritz Canteen doubles the Sentry Gun's firing rate. An Upgrade Buildings Canteen instantly upgrades the Sentry to Level 3. Sentry Guns can also be upgraded at Upgrade Stations to increase their health and firing rate, and the Engineer can even buy a Disposable Sentry Gun, allowing him to place a second Mini-Sentry.

Metal spending priority

When hitting a Wrench on a Sentry Gun, the metal will be spent in a certain order:

Health Upgrade Progress Ammo Bullets Rockets

However, Ammo will usually be filled alongside Health and the Sentry Gun's Upgrade Progress. When Ammo is being filled, the bullets for the Sentry Gun are filled first, then the Sentry Rockets are filled.[1]

Demonstration

Combat Mini-Sentry Gun

“

— The Engineer on his Combat Mini-Sentry Gun I love that little gun! ”

The Combat Mini-Sentry Gun is a more combat-efficient version of the standard Sentry Gun and is a component of the Engineer's Gunslinger unlock. It is a smaller Level 1 Sentry Gun outfitted with a rotating light that glows and is painted with a white checkered paint. Like the Sentry Gun, it can be hauled.

Demonstration

Advantages

Costs only 100 Metal to place (the normal Sentry costs 130 Metal). This allows an Engineer at a full 200 Metal to build both it and a Dispenser without needing additional Metal.

Constructs much faster than the original Sentry Gun. Hitting the Sentry will make it construct faster and when deployed after hauling it will be armed in 1.5 seconds.

Begins construction with 50 health. This makes the Mini-Sentry less vulnerable while under construction when compared to the default Sentry Gun, which begins construction with 1 health.

Fires 25% faster than a Level 1 Sentry Gun.

Can rotate 35% faster than the default Sentry Gun.

Approximately half the size of a regular Sentry Gun, making it harder to notice and target.

More useful for Sentry jumping, as the firing rate and reduced damage combine to deal more knockback for an equivalent health loss.

Disadvantages

Has only 100 health, compared to a Level 1 Sentry Gun's 150.

Cannot be upgraded. The owner and other Engineers can still refill its ammo and health.

Deals only 50% the damage per shot of the original Level 1 Sentry Gun. Combined with the 25% faster firing rate, the damage per second is overall 38% lower (~50 DPS compared to the Level 1 Sentry Gun's ~80 DPS).

Bullets apply significantly less knockback force. (800% knockback multiplier compared to a regular Sentry Gun's 1600% multiplier)

Drops zero Metal when destroyed.

Once a Sentry jump is executed, not exceptionally useful as part of a base in the new area.

Sentry Gun Levels

Level Kill Icon Health Cost

(Metal) Weaponry Damage Ammo 1 Without Wrangler shielding: 150 With Wrangler shielding: 450 130 Single barrel machine gun Damage Maximum ramp-up: 19.49

Base damage: 16

Maximum fall-off: 8.45 Attack interval Without Wrangler: 0.225 seconds

With Wrangler: 0.135 seconds Average DPS Without Wrangler: 71.11-84.44

With Wrangler: 118.52-140.74 150 rounds 2 Without Wrangler shielding: 180 With Wrangler shielding: 540 330 Twin-mounted Gatling guns Damage Maximum ramp-up: 19.49

Base damage: 16

Maximum fall-off: 8.45 Attack interval Without Wrangler: 0.135 seconds

With Wrangler: 0.09 seconds Average DPS Without Wrangler: 118.51-140.74

With Wrangler: 177.78-211.11 200 rounds 3 Without Wrangler shielding: 216 With Wrangler shielding: 648 530 Twin-mounted Gatling guns and rocket salvos Gatling guns Damage Maximum ramp-up: 19.49

Base damage: 16

Maximum fall-off: 8.45 Attack interval Without Wrangler: 0.135 seconds

With Wrangler: 0.09 seconds Average DPS Without Wrangler: 118.51-140.74

With Wrangler: 177.78-211.11 Rockets Damage Maximum ramp-up: 150

Base damage: 100

Maximum fall-off: 52.81 Falloff is calculated from the distance of the Engineer to the target, not from the Sentry to the target Attack interval Without Wrangler: 3.06 seconds

With Wrangler: 2.25 seconds Note: Can be reflected with the Pyro's compression blast 200 rounds

20 rocket salvos Combat Mini-Sentry Gun Without Wrangler shielding: 100 With Wrangler shielding: 300 100 Single barrel machine gun Damage Maximum ramp-up: 9.74

Base damage: 8

Maximum fall-off: 4.22 Attack interval Without Wrangler: 0.18 seconds

With Wrangler: 0.09 seconds Average DPS Without Wrangler: 44.44-55.56

With Wrangler: 88.89-111.11 150 rounds

Advanced Tactics

Related achievements

Sentry Gunner

Accumulate 10 Sentry Gun kills with a single Sentry Gun.





Gun Down

Destroy an active sentry gun using your pistol.





Engineer to Eternity

Kill an Engineer as he repairs his sentry gun while it's under enemy fire. Guns of the Navar0wned

Kill 5 Engineer Sentry Guns while you are standing outside of their range.





The Argyle Sap

Blow up an Engineer, his Sentry Gun, and his Dispenser with a single Sticky bomb detonation.





Best Little Slaughterhouse in Texas

Rack up 5000 kills with your Sentry Guns.

Breaking Morant

Kill 10 Snipers with a sentry gun under the control of your Wrangler.

Building Block

Have a sentry shielded by the Wrangler absorb 500 damage without being destroyed.

Deputized

Get 10 assists with another Engineer where a sentry gun was involved in the kill.

Doc, Stock, and Barrel

Repair a sentry gun under fire while being healed by a Medic.

Frontier Justice

Have your sentry kill the enemy that just killed you within 10 seconds.

If You Build It, They Will Die

Haul a level 3 sentry gun into a position that achieves a kill shortly after being redeployed.

No Man's Land

Use a sentry gun to kill 25 enemy players that are capturing a point. Patent Protection

Destroy an enemy Engineer's sentry gun with a sentry under control of your Wrangler.

Pownd on the Range

Kill 10 enemies outside the normal sentry gun range using the Wrangler.

Revengineering

Use a revenge crit to kill the enemy player that destroyed your sentry gun.

Rio Grind

Perform 50 repairs and/or reloads on a Sentry gun being Wrangled by another Engineer.

Search Engine

Kill 3 cloaked Spies with a sentry gun under control of your Wrangler.

Texas Two-Step

Use your shotgun to finish off an enemy recently damaged by your sentry gun.

Uncivil Engineer

Provide an enemy player with a freeze cam of you and the sentry that just killed them.





Midwife Crisis

Heal an Engineer as he repairs his sentry gun while it's under enemy fire.





De-sentry-lized

Destroy 3 Engineer Sentry Guns.





Constructus Interruptus

Kill an Engineer who is working on a sentry gun. Joint Operation

Sap an enemy Sentry Gun within 3 seconds of a teammate sapping another.





Real Steal

As an Engineer, escape with your sentry as a sentry buster is about to detonate. Undelete

During a wave, use a canteen charged with 'Instant Building Upgrade' to build a new sentry gun within 3 seconds of your previous sentry gun's destruction.

Bugs

The player has the ability to build the Combat Mini-Sentry Gun, while having any wrench equipped, by holding out the blueprints for the Sentry with the Gunslinger and then quickly switching to a wrench. The player will build a Mini-Sentry (it will still cost 130 Metal). This cannot be done vice versa (equipping the Gunslinger while having normal Sentry blueprints out). If this is done with the Jag the Sentry will get the construction boost effect.

Sometimes, when an upgraded Sentry is moved, it will fire a bullet between upgrade stages if pointed directly at an enemy or Wrangled.

Rarely, after removing a Sapper, all of the Sentry Gun's ammunition, including rockets, will be completely gone.

A Wrangled Sentry does not play its rocket-reloading animation.

Wrangling a Combat Mini-Sentry Gun might result in it remaining in the Wrangled state even when the Wrangler is not the currently active weapon. Switching back to the Wrangler corrects the problem.

After the Mini-Sentry finishes its building animation, it sinks into the ground slightly.

Sentry bullets are affected by ramp-up and falloff.

Occasionally, after being built, a Level 1 Sentry will be frozen in animation and not fire any bullets.

There still exists a way to get a Leveled Mini-Sentry on some custom maps.

Sometimes, when a Spy saps the Sentry Gun during it being constructed, the Engineer can not destroy the Sapper, making him have to destroy the Sentry Gun, or let the Sapper destroy the Sentry Gun.

Rarely when a Sentry Gun has been sapped, and the Engineer has changed Class or left the game, the Sapper will appear floating in the air.

The damage of the Sentry Gun's rockets is calculated based on the distance between the enemy and the Engineer, not the Sentry Gun. Therefore, if the Engineer is closer to the enemy being targeted by the Sentry Gun, it will do more damage.

When redeploying a level 2 or level 3 building that is damaged, hitting the building with the Wrench while it is in the upgrading animation stages of redeployment will use the metal supply but does not repair the building.

Trivia

The original Sentry Gun designs were created by Radigan Conagher in 1890. [2] The original and current designs are visually identical.

The original and current designs are visually identical. Valve ordered and received a full size motion-tracking model of a Level 1 Sentry Gun from Weta Workshop.

In the Steam menu, right-clicking Team Fortress 2 and selecting "View Player Manual" will open a PDF of the Sentry Operating Manual. The Sentry Operating Manual uses the recycling sign to tell players they can reuse metal from destroyed equipment. The problem is that the sign itself wasn't created till 1970 when caring about the environment became a concern among college students and later to all kinds of people. The cover of the Sentry Operating itself is more like that of the late 1950s to early 1960s, whereas the game itself takes place in July of 1968 (The Calendars). By that point, the font of "Sentry" was outdated and was no longer being used. Industrial (upon which the game is heavily based) used a very basic font even before that. The Sentry Operating Manual is in color, which would be wrong for an industrial manual as most aren't in color, especially during the 20th century.

and selecting "View Player Manual" will open a PDF of the Sentry Operating Manual. On the back of the Level 3 Sentry Gun's rocket salvo a tab connects three of the four rockets to the device.

Unused content

Unused Sentry kill icon

An unused alternate kill icon for the Level 1 Sentry Gun exists in the game files, shown on the right. Judging by the fact that this icon shows a laser similar to the one caused by the Wrangler, it is assumed Wrangled Sentry kills would have used alternate icons similar to the one shown.



Gallery

Level 1 Sentry Gun.

Level 2 Sentry Gun.

Level 3 Sentry Gun.

Combat Mini-Sentry Gun.

Sentry Gun concept art.

Sentry Gun models with ambient occlusion.

Sentry Gun concept art.

Sentry Gun concept art.

Sentry Gun explosion.

Icon for a hauled item being destroyed via the Engineer's death.

Modifying your Sentry.



Merchandise

References

See also



