Guess Who? is a kids' board game played by two people. Each player has 24 cards with faces on them. The players take turns asking each other questions about the identity of one designated face card among the 24. The person who guesses his/her opponent's designated card first wins.
Vulture has created a downloadable variant of the game for Game of Thrones. You can find it here.
It would really come in handy, since there are so many characters in the series that it's hard for them to keep even themselves straight. You can ask questions like, "Have you had an important body part cut off?" and "Hodor?" and "Are you obsessed with vengeance?"
-via Nerd Approved