The strict definitions of "game" aren't that useful in real world situations.
e.g. the "game" in "game theory" would exclude
many 1-player video games, because "game" is defined as a competition between choices made by 2 or more rational actors. e.g. if you're playing a game in which the enemies move in set routes, it's not a "game" according to game theory because the enemies doesn't make decisions. Additionally, if the enemy only makes predictable moves in response to your moves then it's just reactive and not really in the spirit of "game theory" games. The whole point of them is to make decisions not knowing what the enemy will pick. But then again, game theory
does not say that each game needs a "winner" and a "loser", they just need some quantified outcome of each round (which is called a game).
However, when kids play make-believe it's also called a "game" even though there are no formal rules or win/loss conditions. Pretty much any attempt at a "definition" excludes a large chunk of what are normally considered games:
https://en.wikipedia.org/wiki/Game"A game is a form of art in which participants, termed players, make decisions in order to manage resources through game tokens in the pursuit of a goal". The "make decisions" bit here excludes any purely dice-rolling games from being games, so e.g. Snakes and Ladders isn't a game at all. And Monopoly wouldn't be a "game" at all, if you remove just a few of the rules (no auctions, no trading, no houses). So according to many definitions, Monopoly barely qualifies as a game.
A game of monopoly
can go forever, so it has both infinite play-states and optional end conditions. Dwarf Fortress has end conditions in the sense of fortress destruction / character death. So it has end-states the same as Monopoly. Whether the states are
subjective wins or losses is not important here. e.g. Monopoly's "win condition" of their only being 1 player left is clearly not a
good outcome, since that last remaining player suffers a
loss of income by the removal of all the other players: there is now nobody left to pay rent.
Take another example: Civilization. In "Civ" one end-state is to kill every other civilization, but it's not the only end state. Really, the only difference between Civ and DF is that Civ has predetermined states where the game turns itself off and you can't play anymore. Does that
really make one a game and the other not a game?