Isaac Asimov's three rules of robotics are at the core of all of his robot stories and fans of not only his works, but countless other authors who have touched on a future filled with robots are familiar with the results. But simply re-arranging the order of the stories makes for an entirely different set of scenarios -most of which are terrible. XKCD explores these other outcomes in this simple-but-effective comic.
Via Geeks Are Sexy
Obeying orders is the tricky one... You don't want some random human to order your expensive bot to commit suicide for their own amusement. You don't want them to be used to commit crimes from a safe distance. Etc.