[Spoiler warning: This article references plot points throughout season 4 of HBO’s “Game of Thrones.”]

When 15-year-old Isaac Hempstead Wright isn’t playing Bran Stark on HBO’s “Game of Thrones,” he’s back home in Kent, England, living the life of what he calls a “normal kid”: studying for school, listening to music, and playing Minecraft and other videogames with his friends.

"It’s...