In London last month, a team from Alphabet’s UK-based artificial intelligence research unit DeepMind quietly laid a new marker in the contest between humans and computers. Thursday, it revealed the achievement, in a three-hour YouTube stream in which aliens and robots fought to the death. DeepMind’s broadcast showed its artificial intelligence bot, AlphaStar, defeating a professional player at the complex real-time-strategy videogame StarCraft II.

Learn about your ad choices: dovetail.prx.org/ad-choices