Alien

Aliens are extraterrestrial beings in the Fallout series.

Background
Once thought to be covered up by a government conspiracy and believed only by "crackpot" groups such as the Quaere Verum, evidence of extraterrestrial life can be traced back throughout human history, but became nationally recognized after the mysterious disappearance of the Clarabell 7 space pod during the 1960s Space Race. It is said that the Enclave have access to alien technology and was the basis of many of the Enclave's more exotic and impressive weaponry and robotics, and even toy manufacturers such as Wilson Automatoys weren't immune to these accusations and that the pre-War United States government, which kept its alien specimens mostly in Area 51.

The Brotherhood of Steel and Shi have encountered the bodies of alien life forms or their spaceships. By extension, the Capital Wasteland Brotherhood of Steel and its Brotherhood Outcasts also have access to a part of alien technology; alien power cells can be found at Fort Independence and the Citadel's armory (seen if you choose to destroy the Citadel during Who Dares Wins).

Characteristics
Aliens are small, greenish humanoids that seem to view humans as animals, worthy of experimentation at best and vivisection at worst. They speak in their own language of clicks, high pitched squeaks and wails and thus cannot be communicated with by humans. They are reminiscent of the 1950s style of aliens, mostly Martians. Their hands lack thumbs completely, but the fingers are so long they can wrap around objects.

The aliens seem to be incredibly technologically advanced, capable of spaceflight and technological feats far beyond that of even the most advanced human pre-war technology, such as long-term cryostasis and holograms. They seem to breathe oxygen and subsist on a diet of unknown worm and squid food, having no visible teeth.

Alien soldiers carry shock batons, disintegrators, and atomizers. They prefer to attack their foes in large numbers.

Encounters

 * In Fallout, the Vault Dweller can encounter a downed small saucer and two dead aliens.
 * In Fallout 2, the Chosen One can encounter some things of apparent extraterrestial origin and a dead alien in the Living Quarters of the Sierra Army Depot.
 * In Fallout 3, the Lone Wanderer can encounter aliens on the spacecraft Mothership Zeta and a dead alien at the location of a downed spacecraft - the recon craft Theta crash site.


 * In Fallout: New Vegas with the Wild Wasteland trait, the Courier can find two Aliens and an Alien Captain.

Combat

 * Aliens will occasionally wear helmets, even inside the ship.
 * Inertia suppression fields are sometimes employed by aliens and significantly increase damage resistance; the amount of shots needed to kill a shielded alien tends to at least quadruple. At level 30, a high-ranking Alien with an Inertia Suppression Field can survive slightly more damage than a Super Mutant Overlord. However, the inertia suppression fields don't protect against after-effects such as Jingwei's Shocksword's shock damage or the flamer's burning damage, nor will they have any effect on a reverse-pickpocketed explosive device.
 * Aliens tend to have drones with them.

Crashed ships
Five alien ships are known to have crashed in the United States:
 * An alien ship in special encounter in California (Fallout).
 * Recon Craft Theta in Capital Wasteland (Fallout 3).
 * Another alien ship can explode over the head of the Lone Wanderer in the Capital Wasteland during the Firelance event although the cause of the catastrophe is unknown.
 * At the Citadel, there is information on a terminal (in the A-Ring) about another ship that crashed in a heavily wooded area that the government was not able to reach.
 * An alien ship, with three aliens near it, is just east of Brooks Tumbleweed Ranch in the Mojave Wasteland (Only with the Wild Wasteland Trait) (Fallout: New Vegas).

Weapons
Firearms:
 * Alien atomizer
 * Alien blaster (Two exist)
 * Alien disintegrator
 * Atomic puliverizer
 * Captain's sidearm
 * Destabilizer
 * Drone cannon
 * Drone cannon Ex-B
 * Firelance

Melee weapons:
 * Electro-suppressor
 * Shock baton

Ammo:
 * Alien power cell
 * Alien power module

Turret:
 * Alien turret - Turret which fire electric projectiles.

Vehicle mounted:
 * Death ray - Powerful cannon equipped on Mothership.

Robots and computers

 * Experimental weapons drone
 * Guardian drone
 * Support drone

Vehicles

 * Alien ship crash site in California - A small saucer that housed 2 pilots.
 * Recon Craft Theta - Small alien vehicle, found in Capital Wasteland. Used by 1 pilot.
 * Mothership Zeta - Large alien vehicle located in space near Earth dedicated to study of humanity.
 * The Second Mothership - A ship of the same design as Mothership Zeta, it comes right after Zeta's Bridge is captured by the Lone Wanderer.
 * Firelance Event craft - Identical vehicle to Recon Craft Theta, destroyed by unknown cause while near the Lone Wanderer.
 * Horowitz Farmstead Craft - a Craft the same size as recon Craft "Theta" it was piloted by 2 soldiers and 1 captain.

Medical

 * Abominations - Beings created from humans as a result of alien experiment.
 * Alien biogel - Ingestible and curative gelatin-like liquid (Stated that they pour/rub it into injuries)

Miscellaneous

 * Alien epoxy - Alien repairing agent.
 * Alien homing beacon - A beacon teleportation sent by a Mothership to return quickly.
 * Alien squid food - A strange substance the aliens experiment on that can be used as food.
 * Drone control device - Remote control for drones.
 * Force field generator - Used for protective cover or blocking a passage.
 * Healing archway - Care generator in Mothership.
 * Inertia suppression field - Personal protection shield technology.

Fallout 3
Aliens in Fallout 3 have several tiers, which tier appears is based on the player's level.

‡ Tier 4-6 aliens are equipped with an inertia suppression field which grants them a damage resistance of 50 at NPC level 20, 80 at NPC level 25, and 110 at NPC level 30 (a 110 DR effectively increases their durability by more than 400%).

Behind the scenes

 * The aliens of Fallout 3 resemble Greys, beings commonly described in alien abduction accounts and commonly depicted in 1950's science fiction that have come to represent the "stereotypical" alien.

Appearances
A downed alien spacecraft with two skeletal corpses appears in Fallout, and Brotherhood Scribes, the Shi Emperor and Skynet all make reference to alien technology in Fallout 2. The crashed recon craft Theta spacecraft appears in Fallout 3, and the aliens are the primary antagonists of the Fallout 3 add-on Mothership Zeta. They also make a small appearance in Fallout: New Vegas, if the player has the Wild Wasteland trait. It is an event triggered by the character heading to a remote stop, north of New Vegas, and to the west of the Northern Passage, along the cliffs.