Everything you need to understand or teach The Game of Empire by Poul Anderson.
The Game of Empire is an adventure story set on faraway worlds in a future in which humanity has not only traveled to the stars but has created a huge interstellar Terran Empire. Diana Crowfeather is a teen-age girl who survives on the streets of Olga's Landing, a bustling city full of beings from many different worlds. She has an adventurous spirit and seizes on the first chance she gets to explore other...