The road to the mythical kingdom of Westeros now passes through Boston, as a local video game company launches a new game based on the popular television series “Game of Thrones.”

Titled Game of Thrones Ascent, the game debuts Thursday on the Facebook social network. Fans of the HBO series can play as nobles in the service of the great families portrayed on the show. Facebook friends can join forces online to complete challenging tasks. Or they can compete for the wealth and status they’ll need to sway the destiny of the Seven Kingdoms.