“In the long run, we may become relatively more concerned about digital sentience, including video-game characters, reinforcement-learning agents, and other computational processes. As computing power increases, both on Earth and perhaps eventually in other parts of the galaxy, humans may run massive numbers of computations at high speed, some of which may embody morally relevant processes. Video-game NPCs are one example of this. In addition, as these NPCs become more life-like, intelligent, and affectively sophisticated, the moral weight of any given individual will increase. It’s possible that video games in 50 years will routinely contain characters as sentient as a minnow or salamander is today.”

— Brian Tomasik, This guy thinks killing video game characters is immoral (Dylan Matthews, Vox, April 23, 2014)