Re: 3 laws for AI
Well, they're not just a literary device. They're also a thought experiment in a concise, easily comprehended, logically consistent set of axioms can still produce unexpected results. Asimov's robot stories (and to a lesser extent the novels, which were also significantly concerned with social effects of machine intelligence) are as much about logic and complexity as they are about robots.
Of course that has never stopped people from interpreting them as prescriptive, or even as descriptions of fact. I remember an Asimov editorial from IA'sSFM around 1980 in which he described getting calls from reporters asking about the Three Rules, after a Japanese maintenance worker was killed by an industrial robot.