A visual tour of Riot Games, one of the ‘best places to work’ (photo gallery)

Riot Games has spawned an empire from a single game, League of Legends. The free-to-play multiplayer online battle arena (MOBA) game has become hugely popular. It had more than 32 million active monthly unique players as of a year ago. That number is wildly out of date, but Riot hasn’t disclosed new numbers. At that time, 12 million players were playing every day, and the more than 5 million players were online at peak times.

Whatever the numbers are now, League of Legends is still doing great almost four years after its launch. And Riot Games has grown to more than 800 people in Santa Monica, Calif. The company was named as No. 3 on the list of the best medium-size places to work for in 2013, based on the Great Place to Work evaluation service.