A game is a recreational activity involving one or more players, defined by a) a goal that the players try to reach, and b) some set of rules that determines what the players can do. Games are played primarily for entertainment or enjoyment.
Games can involve one player acting alone, but more often involve competition among two or more players. Taking an action that falls outside the rules generally constitutes a foul or cheating.
All through humanhistory, people have played games to entertain themselves and others, and there is an enormous variety of games types; for specific information about any type, see links at the end of this article.
Philosopher David Kelley, in his popular introductory reasoning text The Art of Reasoning, defines the concept "game" as "a form of recreation constituted by a set of rules that specify an object to be attained and the permissible means of attaining it." This covers most cases well, but does not quite fit with things like war games and sports that are often done not for entertainment but to build skills for later use. In Philosophical Investigations, philosopher Ludwig Wittgenstein argued that the concept "game" could not be contained by any single definition, but that games must be looked at as a series of definitions that share a "family resemblance" to one another.
In a different context, Stephen Linhart said, "People say you have to choose between games and real life. I think this claim that there's a dichotomy is very dangerous."