Sentry Gun
by@SentryGun9990The Sentry Gun (abbreviated to SG), officially known as Sentry Mechanical Firing Device and also known as 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).
A level one Sentry Gun is a single-barrel machine gun with an internal magazine. The Sentry has a motion sensor, as stated in Meet the Engineer and the Sentry Manual.
A level two Sentry Gun appears to use an automatic cranking system to rotate the barrel, as indicated by the 2 electric cables visible. It also has 2 Gatling guns and a laser sight is built into the carbine body. Its ammunition is belt-fed.
A level three Sentry Gun is identical to the level two, with the exception of an additional set of rocket silos on the top, which comes out of the back ammunition housing area.
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 having 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. If a Sentry Gun is sapped, it gains a 33% damage resistance against a Spy's weapons.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 and a minor damage resistance to all Miniguns. 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 melee weapon. 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 team-colored sphere of 1100 Hammer unit radius. A Sentry Gun that is being constructed has 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; however, it 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. Additionally, there is a 30% chance for the Sentry Gun to look up or down 10 degrees each time it rotates 90 degrees. 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 alt-fire button (default key: MOUSE2) rotates the blueprints counterclockwise by 90 degrees.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 an enemy within the range of the Sentry Gun. Enemies detected by a Sentry Gun hear its noise as a slightly different alert noise. All of these scanning noises are silenced when a Sentry Gun is Wrangled.
A Sentry Gun constantly checks if there is an enemy player or building in scanning range with a clear line of sight. If multiple targets meet this criteria, it selects the closest one and switches targets the instant another target is closer, prioritizing players over buildings in its range. Sentry Guns also only attempt to fire once they have lined up with the target, even if firing before then could cause damage to an enemy. Sentry Guns have a maximum rotation and pitching speed when attempting to track a target, which increases with level and is faster than its idle scanning rotation. Sentry Guns still aim and try to fire at enemies even if their ammo reserves are empty.
Sentry Guns cannot see through geometry and Engineer buildings; however, they ignore friendly players.
After running out of valid targets for whatever reason, the Sentry Gun briefly stays pointing in the direction of its last detected target before returning to its scanning sweeps.
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. 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 moving any building). 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.
Like most other weapons, the Sentry Gun's weapons have damage ramp-up and fall-off. Sentry Gun bullet ramp-up and fall-off is calculated based on the distance between the enemy and the Sentry Gun. However, the rockets from a Level 3 Sentry Gun calculate their ramp-up and fall-off based on the distance between the enemy and the Engineer who built the Sentry Gun.
Unlike most other weapons, the Sentry Gun's weapons do not gain Critical hits. It is possible, however, to make the Sentry Gun deal Mini-Crit attacks and damage if its target is coated in Jarate, being Marked For Death, 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.
Sentry Guns are controlled by the TF2 server rather than the Engineer's client. That means Sentry Guns behave the same regardless of the connection quality of the Engineer that built them.Included in the Engineer Update as an unlockable secondary replacement, the Wrangler 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.
In Mann vs. Machine, Sentry Guns can gain benefits from certain Power Up Canteens. An ÜberCharge Canteen forms a Wrangler-esque shield around the Sentry Gun, reducing incoming damage by 90%. Use of a Kritz Canteen triples the Sentry Gun's firing rate. An Upgrade Buildings Canteen instantly upgrades the Sentry to Level 3 as well as fully repair it, however it does not refill the Sentry Gun's ammo. 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 that is slightly worse than a Combat Mini-Sentry.Sentry Guns are damaged by most weapon effects that damage players; however, some 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 weapons or indirect explosions. A destroyed Sentry Gun drops 65 Metal worth of scrap pieces, which can also be picked up by other classes as Ammo.
Sentry Guns do not fire upon enemy Spies that are cloaked. In general, Sentry Guns do not fire upon enemy Spies that are disguised; however, if the Sentry was firing upon the Spy at the time the disguise was activated, it continues to fire upon the Spy until the Spy cloaks, breaks line of sight, or moves out of range. Sentry Guns also do 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.
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 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).
The Engineer, commonly shortened to Engi, Engie, or Engy, is a soft-spoken, amiable Texan from Bee Cave, Texas, USA, with an interest in all mechanical things. He specializes in constructing and maintaining buildings that provide support to his team, rather than being a front line class, making him the most suitable for defense. The Engineer's various gadgets include the Sentry Gun, an automated turret that fires at any enemy in range; the Dispenser, a device that restores the health and ammunition of nearby teammates; and Teleporters that quickly transport players from point A to point B. Because the Engineer's ingenious devices are under constant threat from explosives and devious enemy Spies, a good Engineer must keep his gear under a watchful eye and under repair with his Wrench at all times. When the Engineer needs to get his hands dirty, his trio of generic yet capable weapons, along with the assistance of his helpful hardware, make him more than capable of holding his own in a fight. If need be, the Engineer can even pick up and haul constructed buildings to redeploy them in more favorable locations. While usually viewed as a defensive class, the Engineer has a selection of high-tech weapons that allow him to destroy projectiles or to build faster-deploying, less damaging Sentry Guns, which give him great utility at the front lines too. His Teleporters are also a key point to both the offensive and defensive team's success, allowing slower, heavier classes to reach the front lines quicker. The Engineer is voiced by Grant Goodeve in the game and by Nolan North in the short film Expiration Date.
Sentry Gun:*Beep* *Beep* Engineer:"Whoooowee! Makin' bacon!"