When exactly does it become endgame? I can recognize when I'm playing endgame, but can never tell when, and what move has transited the game into endgame. Is it when you reach a certain move number? Captured a certain number of pieces? I'd like to know. Curiosity, it's killing me.

The line between middlegame and endgame is often not clear, and may occur gradually or with the quick exchange of a few pairs of pieces. The endgame, however, tends to have different characteristics from the middlegame, and the players have correspondingly different strategic concerns. In particular, pawns become more important; endgames often revolve around attempting to promote a pawn. The king, which has to be protected in the middlegame, becomes a strong piece in the endgame. It can be brought to the center of the board and be a useful attacking piece.

very informative, but not actually attentive to the question. thanx for ur answer

Seems to me he answered your question pretty well.  But, to try a more direct approach, I'll say:  1) no, move number has nothing to do with it; 2) having a certain number of pieces left on the board is closer, but still not quite an answer.  Basically (like David says) once there are no longer mate threats and the kings are free to roam around, that's (usually) the endgame.  Also (again like he says) when queening pawns becomes the paramount consideration, that too is the endgame.

To show why simply counting how many pieces are left on the board can be deceptive in these matters, consider the finale of the following study:

http://www.chess.com/forum/view/more-puzzles/very-nice-study-by-albert-beliavsky

You might (erroneously) call that position an "endgame." But really it's the culmination of a very clever and attractive combination. Chess is too subtle and filled with nuance to suffer easily such arbitrary (and manmade) distinctions.

Thank you. I just wanted the answers in someone's own words. David just copied/pasted from wapedia.mobi/en/Chess_endgame. It's not that I care about the copy/paste, I'd already read it before he posted it. Chess.com isnt the only site that has chess answers. Again, I just wanted an answer that wasn't ripped off a website. I know my question was ambiguous and was actually counting on it. I'd like to get as many answers as possible so maybe I should have asked,'When, in your own opinion, does the endgame begin?'

Thank you.

Of course it is a subjective matter. As far as I'm concerned the endgame begins when I say so. Other players can have it begin when they say so in their games. It's just a word; endgame,endgame,endgame-nothing has happened.

I have a suspicion that the endgame begins earlier as a player improves. Great masters will call a position a dull drawn endgame where the rest of us (and the great master when still a feeble student) would think we're still in the middle of a game of chess.

The endgame starts when my objective of a known and hopefully won endgame becomes clear. If I'm still working on mates and creating small weaknesses and placing my pieces for improved scope, it's a middlegame.

My personal definition of endgame is 8 pts worth of pieces or less for each side or 1 queen for each side.  Thus three minor pieces for each side is not an ending even though it is the same value ( 9 pts ) as 1 queen.  That may sound contradictory but I find the definition helpful in my studies.

I dont count the value of an active king in the definition.

According to one of the books I'm reading, the andgame arrives when you no longer have to worry about king safety. there's no exact move, the endgame may be reached after 15 moves or 115 moves.

I think the end game begins when I start looking for checkmates. Usually the end game for me i think (rarely actually do) of how i can sac a piece for a checkmate or a perpetual check. Usually i think if the game is in someones favor then it's the endgame because all that person has to do is wear the other one down.