How these game designers tried to keep to the plot in an open world

Crafting a story has always been tricky in the video game world. And it's only been getting harder. Many of gaming's biggest blockbusters have touted their "open world" environments -- worlds that let players run down roads less traveled with more side quests than you could shake a machine gun at. Yet while players have liked the feeling of having no limits, there's been some backlash, too. Gamers prefer having a plot.