Turrets are defensive structures that can be crafted after being researched. They come in three different types with different health, shooting speed, range, ammunition, damage type and damage per shot.
Gun turrets are very basic and cheap defensive structures and the simplest element of automatic defenses. They use magazines for ammunition which can be refilled manually or by inserters. They do not require power and can operate practically anywhere as long as they have sufficient ammunition. Gun turrets deal double damage per shot as compared to the man-portable pistol and submachine gun, but have somewhat lower fire rate than the latter, so absent any turret-specific upgrades it does 1.33 times as much damage per second as the submachine guns. The gun turret receives bonuses from technologies that improve bullets so it keeps pace with the submachine gun as those improve, and they also receive bonuses from their own damage upgrade. These two damage effects stack multiplicatively: fully upgraded, bullets do 2.2 times as much damage as a standard bullet, and turrets do 2.2 times as much damage as a standard turret, so bullets from a turret do 2.2×2.2=4.84 times as much damage as without the upgrades, totaling 19.36 damage from regular and 48.4 damage from piercing bullets, more than fully-upgraded laser turrets can provide, though still not quite enough to kill medium spitters in a single shot.
If one plans to exclusively use gun turrets, using a Train to send ammo to restock distant turrets is very effective.
|Recipe:||+ + + =>|
|Damage||Based on ammunition damage (Physical)|
|Shooting speed||10 shots/second|
Laser turrets are an advanced defense building with a longer range, good damage and use electricity to operate (and a smaller amount of energy when idle). By dealing laser damage they don't face any resistances (enemies receive full damage) but have a lower rate of fire than gun turrets. Each shot costs a constant 800kJ of energy; as the shooting speed increases through upgrades, so too does the power required to keep firing.
Since using laser turrets to ward off attacks can cause electricity usage spikes, using accumulators to offset the cost is recommended to keep the rest of the network fully functional.
|Recipe:||+ + + =>|
|Max power:||2.4 MW (electric)|
|Energy consumption on standby||24 kW|
|Shooting speed||3 shots/second|
New in version 0.13, Flamethrower turrets provide literal fire support, setting enemies on fire and doing damage over time. Unlike the previous turrets, they have a limited firing arc, therefore should be place at choke points or behind walls. They use liquids as ammunition, which requires dedicated fluid pumping, capable of using crude oil, heavy oil, or light oil. Different liquids provide further damage bonuses. (Light oil yielding a 10% damage boost.)
Currently, flamethrower turrets have a tendency to miss the first row of biters, as unlike the laser and gun turrets they do not have a seeking projectile, instead firing over the heads of the first row. Due to this, gun/laser turrets will be necessary in addition to flame turrets. The second biters in line will not be so lucky, however. When fully upgraded, Flamethrower turrets are capable of doing 145.2/s Fire damage plus an additional 217.8/s damage for 8 seconds. This makes them far more powerful than the gun turret or the laser turret, especially considering Biters' lack of resistance to fire. The high damage cheapens the cost of liquids.
The optimal attack for flamethrower turrets to handle would be a very linear attack, where the enemy attacked in a line formation, to ensure most attackers end up walking through the pool of fire left by the turret.
|Recipe:||+ + + + =>|
|Total raw:||+ +|
|Fluid Consumption||0.12/s while firing (zero while idle)|
|Damage Over Time||45/s (Fire) for 8 seconds|
|Area of Effect size||2.5 tiles|
|Damage modifiers:||= 100 % = 105 % = 110 %|