There are a plethora of games in the world whose only "win" condition is "how long can we keep this up?" I guess that is a kind of win condition, but, it's not what I think you're referring to RC. It's not a game where you really win, but, simply have degrees of losing.
If I play Pac Man for three minutes or thirty minutes, did I win at Pac Man?
I believe that, upthread, in this thread or another, I described a game in which the win conditions include simply beating your previous best (Bus Depot Diner). A game can certainly have degrees of victory; victory conditions do not need to be zero-sum.
Truth or Dare is an excellent example of a game that seems very simple at first glance, but when examined closely reveals strategy, social engineering, bluff, and theory-of-consciousness elements. At a glance, the goal is "how long can we keep this up?" but when examined more closely (and certainly when actual play is examined) the game is really won on the basis of information exchange.
If a player selects "Truth", he has the option of attempting to bluff, should the question he is asked be one he does not wish to answer truthfully. Failing in this usually ends the game, and at the same time the failed bluff often reveals the truth the player was attempting to hide.
"Dare" exists as a counterpoint to "Truth", without which many people might not play. Dares typically become increasingly difficult as the game progresses for two reasons: (1) for the same reason Truths do, as outlined below, and (2) to give players increasing reason to select "Truth". Obviously, you can balk at a Dare, but doing so forfeits the game.
Truths tend to be tentative at first, because (1) players wish to have "Truth" selected, and (2) upping the ante for others automatically ups the ante for yourself as well. Moreover, players are less likely to balk with a slowly progressing degree of personal information required. I.e., sharing smaller confidences makes it easier to share larger confidences.
Note also that Dares and Truths are often intertwined, based upon what the other player actually wishes to know. Thus, selecting "Truth" might lead to "Do you like me?" while selecting "Dare" might lead to necking for five minutes alone in the closet -- the same information is conveyed either way.
Each player is also trying to limit his or her own vulnerability. Thus, if Joe wants to know if Sarah likes him, Joe might ask as a series of Truths: "Is there any boy you like?" "Do you like anyone in this room?" and "Who?" in an attempt to limit his vulnerability by admitting that he likes Sarah. Of course, he is also fencing with his answers/Dare responses, to avoid revealing the same (or other information he might not wish to reveal).
There is a reason why Truth or Dare is played mostly by adolescents, teenagers, and unattached groups of young adults. Successful play can often lead to sexual encounters (to one degree or another). Of course, successful play also generally requires that the participants pretend not to understand what the win conditions are, or what their end goals are.
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In Pac Man, the win condition is not simply "How long can I keep this up?", but rather "What score can I achieve?" The score is there to make objective how well you did. Indeed, if you do well enough, you get to place your initials on the machine's "High Score" so everyone can see how good you are.
When you play Pac Man, the outcome of the victory conditions is unknown (i.e., you do not know what your score will be), and the outcome is directly related to the choices you make. It is, therefore, a game.
What the victory conditions (goals) are is unimportant when determining if something is a game; there must be victory conditions, however.
RC