From the introduction: First family is an RPG about the survival of those first men who faced dinosaurs. The world is a harsh unforgiving place and you are going to kick reptile butt, gather food and protect your cave. The key element as to what makes First Family different is the use of a limited language called Cave Tongue. Cave tongue has a limited number of core words and the players must expand their language but using gesture and drawing as well as words, if they are to survive.