Three Laws of Robotics

The Three Laws of Robotics were created by Isaac Asimov for his Robots novel series. They state: Howard and Raj have accused Sheldon of being a robot based on the fact that he has never broken any of the Laws.
 * 1) A robot may not injure a human being or, through inaction, allow a human being to come to harm.
 * 2) A robot must obey any orders given to it by human beings, except where such orders would conflict with the First Law.
 * 3) A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.