While robots' capacity to pass for human can be measured by Turing or Voight-Kampff tests or various other criteria, films that feature them are often simultaneously testing the humanity of the non-robotic characters around them, as well as of viewers whose emotional response to the constructs projected on screen constitutes our ability to empathise even with artificial stimuli.
Robots, in other words, represent a fluid boundary against which our own humanity can be charted. They differ from us, and yet in certain respects are like us and often want little more than what we have: our freedom, our feelings, our fleshy form.
Here are 10 key robot films.