A game is a structured form of play characterized by a set of rules, interactivity, and feedback that result in a quantifiable outcome often eliciting an emotional response. The term can refer to a broad range of activities, from competitive sports and board games such as checkers, Monopoly, and Connect Four to simulated wargames and virtual reality simulations. Some games help to develop practical skills, serve as a form of exercise, or perform educational or socially important functions, while others provide entertainment, a challenge, and/or a chance to win or lose.

While some definitions of games are quite expansive, most scholars agree that there are certain essential aspects to any game. In general, a game must involve competition and adversary, but this is less important than the fact that a game is an activity that exists in auxiliary or parallel space to the players’ quotidian life. Furthermore, games must be able to be played by individuals of all ages, genders, and socioeconomic status. Finally, the rules that govern the playing of a game must be sufficiently inefficient to encourage players to take risks and explore new possibilities for achieving their goals.

The most widely accepted definition of game is that it is a system of rules governing the interactions and outcomes of play. The definition goes on to note that the goal, challenge, and outcomes of a game are distinct from those of other kinds of activities, but that there is also a kind of mystical or magic circle between players where they are constantly given the opportunity to exit the game by agreeing to its rules.

Almost all definitions of game consider the need for a set of rules that are agreed upon by all players (either in advance or during gameplay) and that make the playing of the game fair to all participants. Some authors have suggested that this should include the ability to make small changes to the rules of a game, such as house rules, so long as the overall structure of the rules remain the same.

However, it is possible to have a useful definition of game without taking previous research into account (although this may be more difficult and prone to running into problems that others have already overcome). There is nothing stopping anyone from defining a game in any way they want, although doing so will require careful thought about the context within which a particular game should be defined.

A number of scholars have argued that the definition of game used in videogame studies is too restrictive, and that there are other activities that could be described as games (including many types of sport, art, and a variety of forms of entertainment). These criticisms usually focus on the idea that a game needs to be a digital or electronic experience, or that it must involve interaction with a computer screen or an artificially intelligent agent in order to be considered a game.