Grasshopper: Games, Life, Utopia, by Bernard Suits
A retelling of Aesop's fable of the Grasshopper and the Ants, Grasshopper is an engaging and insightful book that addresses some of the philosophical paradoxes raised by games. Cheating, rule-following, and the reality of games versus the real world are among the topics Suits addresses. It is from this book that we derive our concept of the lusory attitude, an important game design concept.
Recommended:
Chapter 3: Construction of a Definition
Chapter 4: Triflers, Cheats, and Spoilsports
Homo Ludens, by Johann Huizinga
Perhaps the most influential theoretical work on play in the twentieth century, in Homo Ludens (Man the Player), Dutch philosopher and historian Huizinga explores the relationship between games, play, and culture. His point of view is certainly not that of design; however, Huizinga's work directly influenced many of the other authors we reference here, such as Roger Caillois and Brian Sutton-Smith. In the chapter recommended below, Huizinga establishes his essential definition of play.
Recommended:
Chapter 1: Nature and Significance of Play as a Cultural Phenomenon