Charades, which continues to be played in a modified form even today, is a game about acting. This game sets up a clear parallel to how Becky (and to an extent, many of the other characters) are essentially actors as they try to put forward a carefully cultivated persona in public. It makes sense that the charades game takes place at Lord Steyne’s house, the place where Becky practices her acting when she pretends to be a respectable member of high-class society.