Protectron (Fallout 3)

Protectron is a pre-war robot type, shaped per the classic Robbie the Robot model. Their primary function seems to be protection, their secondary programming is very modular and they can do many things from being greeters, to ticket-takers and bartenders, to even functioning as celebrity/historical figure impersonators. They were created by the RobCo corporation.

Removal of the combat inhibitor on a Protectron's back (say, shooting it off) will cause the robot to frenzy, attacking friend and foe alike.

Many Protectrons in various areas have been programmed differently; the Protectrons within the Nuka-Cola Factory, for example, mention that they are operating under the authority of Nuka-Cola as they attack you, with the words "Nuka-Cola!" being dubbed in from an exterior source. Other Protectrons have even been supplied with sophisticated personalities, such as the one guarding The National Archives, but these are the exception rather than the rule.

Appearances
Protectron robots appear only in Fallout 3.

Protectrons seem to have a weakness to Flamer and other weapons that use fire.

Known Protectron robots
Deputy Weld

Shakes

Button Gwinnett

Ticket Bot