Arm wrestling

Arm wrestling is a physical game played on Earth in which opponents attempt to force the other person's hand to the table or other surface being used. Sullivan's pub was a common place for this game. Harry Kim once defeated an opponent Liam, who seemed to be much more powerful than him. 

Klingons raise the stakes by having a d'k tahg on either side of the arms. Thus, whoever loses gets their hand impaled.