Turret

Automated Turrets are automatic, unmanned machine guns which are capable of sensing and attacking targets that are hostile to the faction or organization to which they belong.

They are employed by both military organizations like the Enclave or Brotherhood of Steel, and civilian operations such as the Museum of History, though in the latter case their former operators have been long since gone. In one case, a Raider group near the Arlington Library has reprogrammed turrets to protect a camp and a drug lab.

Variants
Automated turrets can rest on the floor or hang from the ceiling. The ceiling turrets use bullet-based weaponry whereas the ground turrets are equipped with lasers. Both variants have unlimited ammo. For conversation and reference purposes, odd-numbered turrets ( Mark I, Mark III, etc.) are 5.56, ceiling turrets while even numbered turrets (Mark II, etc.) are ground-mounted, laser turrets.

The Turrets aboard Mothership Zeta are simply known as "Turrets"

The following models exist: There are a few, stat-wise identical versions of each model in the game (with different Base IDs) for different factions.

Tactics

 * Turrets are generally controlled from a nearby terminal. Using your Science skill to hack the terminal will allow you to override the targeting parameters - which will make the turret target any character (not just the player) or shut it down completely. After being turned off the turret can be turned back on at the same terminal if so desired.
 * Shooting at the targeting module carries a high chance of the turret becoming frenzied, and attacking everyone.
 * The ceiling-based turrets have a blind spot directly below them, making it a key location for attack.
 * The Enclave Officer at Camp RHO carries a special keycard named Experimental Rho ID. Once you have it the turrets in the camp are no longer hostile.
 * With the Robotics Expert perk, it is possible to sneak up on turrets and disable them. You need not necessarily be  [HIDDEN] , simply being momentarily out of sight is enough to deactivate them.
 * You can use a dead body to get past a turret(they won't shoot if the body is directly blocking their view). Be careful not to sway or run, as the body moves out of place, the turrets will take advantage of an open shot. (tested PS3)

Appearance
Automated turrets can be found in many locations in Fallout 3 and its add-ons. Mark VII and Mark VIII turrets only appear with the Broken Steel add-on.