Disk Dueling was an illegal sport on Metru Nui that involved two Matoran throwing Kanoka at each other. It was very popular, especially for settling arguments. The results, however, could be disastrous: Not only could Matoran be injured by the force of the throw, they could become victim to the Disk's powers. Its relation, if any, to the Kanoka Disk Toss disk-catching sport is unknown.