In a corner of Alphabet’s campus, there is a team working on a piece of software that may be the key to self-driving cars. No journalist has ever seen it in action until now. They call it Carcraft, after the popular game World of Warcraft…

…Scenarios like this form the base for the company’s powerful simulation apparatus. “The vast majority of work done—new feature work—is motivated by stuff seen in simulation,” Stout tells me. This is the tool that’s accelerated the development of autonomous vehicles at Waymo, which Alphabet (née Google) spun out of its “moon-shot” research wing, X, in December of 2016.

If Waymo can deliver fully autonomous vehicles in the next few years, Carcraft should be remembered as a virtual world that had an outsized role in reshaping the actual world on which it is based.