Android

Androids, also called synthetic humanoids or synths, are artificial intelligence units designed to look and behave like humans.

Background
The Institute in the Commonwealth has been able to create androids. These androids, according to Dr. Zimmer, have fake skin, and blood, and are programmed to simulate human behavior, like breathing. They can even eat and digest food realistically. The androids created in the Commonwealth have no rights, and are viewed as nothing more than machines. They are often used as slaves. Any android that attempts to escape is hunted down by the Synth Retention Bureau, a special branch of the Commonwealth Police.

These escaping androids, that are hunted down by specially trained trackers, appears to be an homage to the sci-fi classic Blade Runner. The terms "synthetic humanoid" and "synth" are very similar to the androids of the "Alien" films and comics.

Related quests

 * The Replicated Man

Appearances
Two confirmed androids appear in Fallout 3. Others have been debated, though it is merely speculation. They are:
 * Harkness
 * Armitage