Number of moves

Is there a limit to the number of moves in a tournement game?

NO (in general)- and YES (specifically) - there is a "50 move rule" in which the game is a draw if 50 consecutive moves are made without a pawn move or piece capture. (For instance, so that bozos who don't know how to mate with K+B+N vs K can't learn it OTB by making you sit at the board for days, wks or years until they "get it.") And there is a "triple repetition rule" in which the game is drawn if a player announces it prior to making his/her move that will result in a triple repetition of the exact same position - and it doesn't have to be three moves in a row either which can get confusing, esp in time pressure.

Other than that, the other reasons for ending a game don't directly relate to limiting the number of moves: checkmate, stalemate, insufficient material or both players simply agree to a draw.

However, the fifty move rule must be claimed by the player who desires a draw.  so in theory after a minimum of 126*50 = 6200 moves either player will have the RIGHT to a draw, but NEED NOT claim it.  So no, there is no limit to length.

@tazerdadog Where does the 126 come from? Yo no comprendo...

126 = maximum number of 50-move-rule resetting moves in a game.

I still don't get it - what's the rationale/reasoning/proof (or where is it online)

The 50 move rule is reset by a pawn move or a capture.  15 captures per side are possible in one game. 6 moves per pawn per game are possible.

((6(8) + 15)x2)x50 = 126x50 = 6200

OK I figured there was some formula but I was too lazy (or senile) to try figuring it out. Thanks for providing it.

So what happens in a tournament game if two players decide to keep playing forever without claiming a draw (say time controls have 5 seconds delay, and players take less than that for each move)?

Does the TD eventually steps in to declare it a draw?