In the German language a game is any activity which is executed only for pleasure and without conscious purpose. In this definition every activity that brings pleasure is a game. For example, people dance, play musical instruments, act in plays, and play with dolls and model trains.
This definition people use today comes from the works of Johan Huizinga (Homo Ludens, 1938) and Friedrich George Jinger (Die Spiele, 1959). But there are more ways to define games. Manfred Eigen's and Ruthild Winkler's definition for game goes beyond the definition used by Huizinga. They see a game as a natural phenomenon: half necessity and half coincidence (Das Spiel, 1975). Their definition of games comes closer to Adornos' definition, who set himself apart from Huizinga by identifying games as an art form.
I will now try to find the criteria for defining "game with rules". Kevin Maroney defined game in his Games Journal article, My Entire Waking Life. Scott Kim defined puzzle in his Games Cafe article "What Is a Puzzle?" as separate from a game. Kate Jones writes about less aggressive games in her Games Journal article Non Predatory Games. My definition is a further attempt to explore the nature of games.
Whoever reads a book, watches a movie, or listens to music, consumes or acquires, but does not act. While nowadays most leisure activities seduce people into passivity, the game makes people act. Depending on the game, the following activities may be undertaken:
I am sure that games do not fulfill a purpose, but are not useless. Activity is basic to all games. Here again, the embracing game term has its value.