A couple years ago, Google pitted AlphaGo -- an AI designed to master Go, a famous chinese board game, by watching other players and learning from their actions -- against the world's top players. The results shocked the gaming world: AlphaGo beat Ke Jie, the Go world champion. But that was just one surprising AI gaming experiment among many over the next few years. Big-name video game companies like Blizzard Entertainment, EA, Apex Game Tools and others have started using AI to change the face of their industry. How are they doing it?