http://www.jesperjuul.dk/text/gameplayerworld/

In this text, the author, Jesper Juul looks at the previous definitions of games and then proceeds to argue for the following new definitions:

A new definition: 6 game features

The game definition I propose finally has 6 points:

1) Rules: Games are rule-based.

2) Variable, quantifiable outcome: Games have variable, quantifiable outcomes.

3) Value assigned to possible outcomes: That the different potential outcomes of the game are assigned different values, some being positive, some being negative.

4) Player effort: That the player invests effort in order to influence the outcome. (I.e. games are challenging.)

5) Player attached to outcom: That the players are attached to the outcomes of the game in the sense that a player will be the winner and "happy" if a positive outcome happens, and loser and "unhappy" if a negative outcome happens.

6) Negotiable consequences: The same game [set of rules] can be played with or without real-life consequences.

A game is a rule-based formal system with a variable and quantifiable outcome, where different outcomes are assigned different values, the player exerts effort in order to influence the outcome, the player feels attached to the outcome, and the consequences of the activity are optional and negotiable.

Source	Definition
Johan Huizinga 1950, p.13.	[...] a free activity standing quite consciously outside "ordinary" life as being "not serious", but at the same time absorbing the player intensely and utterly. It is an activity connected with no material interest, and no profit can be gained by it. It proceeds within its own proper boundaries of time and space according to fixed rules and in an orderly manner. It promotes the formation of social groupings which tend to surround themselves with secrecy and to stress their difference from the common world by disguise or other means.
Roger Caillois 1961, p.10-11.	[...] an activity which is essentially: Free (voluntary), separate [in time and space], uncertain, unproductive, governed by rules, make-believe.
Bernard Suits 1978, p. 34.	To play a game is to engage in activity directed towards bringing about a specific state of affairs, using only means permitted by rules, where the rules prohibit more efficient in favor of less efficient means, and where such rules are accepted just because they make possible such activity.
Avedon & Sutton Smith 1981, p.7.	At its most elementary level then we can define game as an exercise of voluntary control systems in which there is an opposition between forces, confined by a procedure and rules in order to produce a disequilibrial outcome.
Chris Crawford 1981, chapter 2.	I perceive four common factors: representation ["a closed formal system that subjectively represents a subset of reality"], interaction, conflict, and safety ["the results of a game are always less harsh than the situations the game models"].
David Kelley 1988, p.50.	a game is a form of recreation constituted by a set of rules that specify an object to be attained and the permissible means of attaining it.
Katie Salen & Eric Zimmerman 2003, p.96.	A game is a system in which players engage in an artificial conflict, defined by rules, that results in a quantifiable outcome.




http://en.wikipedia.org/wiki/Game

A game is an (often, but not always recreational) activity involving one or more players. This can be defined by either a goal that the players try to reach, or some set of rules that determines what the players can or can not do. Games are played primarily for entertainment or enjoyment, but may also serve as exercise or in an educational, simulational or psychological role.

http://www.google.com/search?hl=en&lr=&client=safari&rls=en&oi=defmore&defl=en&q=define:game

 

Definitions of game on the Web:

*a single play of a sport or other contest; "the game lasted two hours"

*a contest with rules to determine a winner; "you need four people to play this game"

*an amusement or pastime; "they played word games"; "he thought of his painting as a game that filled his empty time"; "his life was all fun and games"

*the game equipment needed in order to play a particular game; "the child received several games for his birthday"

*your occupation or line of work; "he's in the plumbing game"; "she's in show biz"

*plot: a secret scheme to do something (especially something underhand or illegal); "they concocted a plot to discredit the governor"; "I saw through his little game from the start"

*crippled: disabled in the feet or legs; "a crippled soldier"; "a game leg"

*bet on: place a bet on; "Which horse are you backing?"; "I'm betting on the new horse"

*willing to face danger

*frivolous or trifling behavior; "for actors, memorizing lines is no game"; "for him, life is all fun and games"

http:///wordnet.princeton.edu/perl/webwn

 

A game is a recreational activity involving one or more players. This can be defined by A) a goal that the players try to reach, B) some set of rules that determines what the players can or can not do. Games are played primarily for entertainment or enjoyment, but may also serve an educational or simulational role.

http://en.wikipedia.org/wiki/Game

http://www.erasmatazz.com/library/JCGD_Volume_4/DefinitionGame.html

"Puzzles" are challenges with no purposeful opponents. They have a clearly defined goal and a variety of obstacles that the player must overcome to achieve the goal. The obstacles may be active or dynamic, and may even have behavior patterns of their own. However, so long as the player does not attribute to their behavior a purposeful attempt to foil his actions, they are obstacles rather than opponents and the chal-lenge is a puzzle. The majority of entertainment software products are puzzles. Adventures, for example, whether text or graphic, are puzzles. Tetris and its clones are puzzles.

 "Conflicts" are challenges with purposeful opponents. There are two subclasses of this class: competitions and games. They are differentiated by the ability of the opponents to impede each other's performance. If the opponents are constrained from impeding each other and instead devote the bulk of their attentions to maximizing their own performance, then the conflict is a competition. If on the other hand, they are permitted to hurt each other's performance, then the conflict is a game.

 "Competitions" are conflicts without impeding action between the competitors. Examples are races and political campaigns. It is almost always against the rules of a race for the racers to take direct action against each other (tripping, stabbing, mudslinging.)

This leaves games as conflicts in which the players directly interact in such a way as to foil each other's goals. In other words, if you can shoot back at the other guy, and he shoots at you in a manner that convinces you that he's out to get you, then it's a game. Their Finest Hour, Railroad Tycoon, Second Front and Trust & Betrayal are all games.