MOST STUPID RULE : STALEMATE

Urban Legend: before Chess (an archaic work for Check), we had Capture, a game to capture the opponent's King. A King took it a bit too personally and executed the person whom taught him the game.

Or it could be the best rule ever--you are about to lose and Ola! Stalemate!

It exists because otherwise the game would fall apart. The player could have like 18 minutes left and has to wait them out. This would make the (most likely winning) opponent mad.