Three Laws of Robotics from I, Robot

Three Laws of Robotics:

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 the orders given 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.