Missile turret

"I hate these things. They can sense me even when I'm cloaked. We should take these out."

- Sarah Kerrigan

The Missile Turret is a Terran defense building designed to take out air units and detect both invisible and burrowed units.

Background
"Missile turrets are relatively inexpensive structures that will automatically target and fire upon incoming enemy aircraft. They also serve as sentry stations equipped with powerful sensors capable of detecting cloaked vessels."

"The various Terran military factions all benefit from the hardware and advanced weaponry produced by the colonies of the Koprulu Sector… Although most Terran tanks, starfighters, and war machines were designed and produced by privately owned corporations, the plans and technical layouts have been stolen, pawned, smuggled out and put into the hands of various faction scientists."

The Missile Turret fires a self-guided warhead called a "Longbolt Missile". This weapon does explosive damage, and so does half damage to small air units like Mutalisks and full damage to large units like Battlecruisers, unlike the Protoss Photon Cannon or the Zerg Spore Colony, which deal full damage to any unit, regardless of size.

Although primarilly automated, Missile Turrets are capable of being controlled manually. In this case, the missiles can be fired at ground targets also.

Given the constant Terran inter-colonial warfare prior to the events of Starcraft and given the above description, it is probable that by the time the Zerg and the Protoss arrived in the Koprulu Sector, the Missile Turret was a standard colonial defense system for most Terran installations, regardless of faction. This becomes even more likely when one considers that inter-colonial attacks would most likely involve some combination of bombardment by capital ships, assaults by fighter craft (including the Wraith, accounting for the Missile Turret's detection capabilities), and incursions by troop transports, all of which would fall under the jurisdiction of a defense system such as the Missile Turret.

In-Game unit
The Missile Turret is the Terran equivalent to the Zerg Spore Colony. They are best used in groups and/or in conjunction with Terran Bunkers, given their relatively low HP.

Missile Turret

 * Costs 75 minerals and no Supply.
 * Stationary (cannot evade Disruption Webs or maneuver into range of long-range air attacks); also, due to their stationary nature, individual Missile Turrets can become isolated or even avoided entirely by mobile forces, and a missile turret that can't take part in the defense of a base is a waste of 75 Minerals.
 * Detector
 * 200 Health
 * 1 armor
 * 20 Explosive damage against aerial targets, doing half damage to small units (like Mutalisks) and full damage to large units (like Battlecruisers).
 * Neither damage nor armor can be upgraded, reducing the Missile Turret's effectiveness in the late game.
 * Like all Terran structures, it will take damage over time if its health falls into the red
 * Attack cooldown significantly better than the Goliath's (1.5 times faster)

Goliath

 * The Goliath costs 100 minerals, 50 Vespene gas and 2 Supply.
 * Mobile, and so capable of avoiding Disruption Web or moving into range of long-range units, but as a consequence, it can be affected by Psionic Storm. On the other hand, it may also be given Defense Matrix, unlike a Missile Turret. Furthermore, the Goliath can stand on terrain locales where Missile Turrets cannot be built, and multiple Goliath units can move into position to focus fire on enemy units.
 * 125 health (significantly less)
 * 1 base armor
 * 20 base AA damage. Unlike the Missile Turret, the Goliath can attack ground targets for 12 base damage.
 * Damage and armor can be upgraded, for a total of +12 AA damage, outstripping the Missile Turret by a significant margin. This results in greater damage per second from the Goliath against air/space targets.

Trivia: it takes 28 hits from a fully-upgraded Zergling to kill a Missile Turret; it takes 31 such attacks to kill a fully-upgraded Goliath. And the Goliath can shoot back, unlike the Missile Turret.

Missile Turrets in StarCraft II
Missile Turrets feature in the gameplay footage of StarCraft II released in May 2007. Interestingly, they have been shown in the Artwork Trailer to be able to attack the Protoss Colossus units; Blizzard has confirmed that this is because the Colossus is so tall that it counts as both a ground and air unit for the purpose of what attacks are able to hit it.

Missile Turrets now fire two missiles per "volley". Each missile does 5 damage, with +2.5 damage against "medium" units and +5 damage against "armored" units. This effectively matches the amount of explosive damage inflicted by the StarCraft I version of the Missile Turret (10 vs small, 15 vs medium, 20 vs large units) except armor applies twice.

Missile Turrets lose the detector ability but Sensor Towers and Radar Towers grant detection to Missile Turrets within an area.