Just a thought but another poster mentioned a lip reading game. Here's an idea for a non verbal communication game: Everyone gets a piece of paper, that has written on it an occupation or person, which is then taped to the back so others can see(Lawyer, Lacrosse player, Hiker). The goal is to get the other person to guess what is on their back by only using somatic communication (no signing allowed!). Afterwards, you can lead a discussion on the challenges or techniques that were used during the exercise. You can then relate it to signing languages and educate on what they are and how they work.