It’s common to wonder what your friends really think about you, but how can you ever know for sure? Surprisingly enough, HBO and Facebook have an app for that.

In order to promote the April 1st premiere of HBO’s returning soap-opera-with-dragons series, Game of Thrones, Facebook has unveiled a new game that pits fans of the series against each other in a loyalty contest to be judged by the players’ mutual friends in secret. The app, created by BBDO New York, requires a webcam to use, but for a very good reason. After players challenge their Game of Thrones-loving friends to battle, both graft their faces onto dueling fighter avatars; and once it’s all over and a group of friends votes on who they want to win, a first-person POV video plays, showing the winner vividly beheading the loser and finally holding up the head of this now-vanquished foe.

Watch the video for the app below, and let the games begin.