Sam Riegel and Travis Willingham tell IndieWire about the "Critical Role" journey from livestream to producing animated series. Either you already know what “Critical Role” is, or you don’t have any D&D nerds in your life — and if that’s the case, you should fix that. But as Sam Riegel and Travis Willingham, two executive producers and lead nerdy-ass voice actors behind the show that has done as much as “Stranger Things” to generate cultural interest in Dungeons and Dragons, look back on