In the works of science fiction author Isaac Asimov, all robots are programmed to follow three specific rules known as the Laws of Robotics.
A robot must never harm a human being, or allow a human to come to harm through inaction.
A robot must obey all orders given to it, except those which contradict the first law.
A robot must defend its own existence, unless doing so conflicts with the first two laws.
All of Asimov's works make mention of the Three Laws. The Laws have even been borrowed by others and have been featured in other works of media, such as the Mega Man video games and the movie I Robot, which was based on Asimov's short stories.