What is a Game?

I thought I knew what a 'game' was until I tried to define what makes a game a game and not something else.

In the end the only definition I can come up with that seems to fit is:

A game is any activity that involves play

So, then what is play?

Play is anything that is done as a physical or intellectual stimulation of an individual and is not done for any other reason

The problem is that this seems to broad. I would have thought that a game could be defined as:

A game is a directed activity that has an outcome that is dependent on the actions of the player or players of the game

It has to be a 'directed activity', meaning it must take place within a defined structure that has known boundaries and must lead from a known start state to a definable end state. Within these limits the player(s) must be able to perform actions that have a direct result on the outcome of the game. The player must know the nature of the outcome they are attempting to achieve in order to make meaningful decisions about their actions within the game.

Applying this to recognised games:

• Chess - Yes this works
• Barbie Doll - No, it is not a game; No definable end state, no dependent actions
• The Sims - No, it is not a game; No definable end state, no dependent actions, there are actions which change the state but these do not have a direct result on any definable outcome.
• Space Invaders - Yes, it is a game; The defined outcome is a 'high score', the actions of the player have a direct effect on the final outcome (i.e. the score archived before you die). It is important that you die sooner or later, otherwise the high score is meaningless.
• Half Life (any FPS) - No?; The outcome is that you get to the end? but it is not a race so what is achieved by getting to the end? Does it matter in anyway that you get to the end? Not as far as I know, so it is not a game.
• World of Warcraft (any MMO) - No; There is no outcome, the actions of the player have no effect on the play field, It makes no difference whatsoever how you get from one state to the next.

So it goes on, there appears to be a problem with the definition of 'game' or there is a problem in the way that Digital Games are regarded? I can imagine that the lack of a definable outcome to many computer based games would lead people to 'give up' playing them after a while, once the 'experience' of the play becomes the only reason to continue and the 'game' has no other qualities. Hence I can see that such 'games' can only be played once. Is it part of the Design of computer games that they cannot be replayed? Is the experience of replaying the game so similar each time that it very quickly becomes lame and tired and people give it up?