50 move rule
If there have been 50 moves with no captures or pawn moves a draw can be claimed. Here, the draw is automatic for live Chess
If 50 moves have been done with no capture or pawn move, the game is automatically drawn. A few decades ago it was changed to 75 and later 100, but then was reverted back to 50, which has remained since.
This type of draw almost never occurs in practice, as it's generally very obvious when a position is a dead draw; therefore, players will almost always agree to a draw before a game comes close to it. Not to mention, 50 moves is a very long game; not many get that far.