The game consisted of an iridescent sphere, which the player attempted to turn into a solid color. To do so required complete clarity of the mind, and the player needed focus entirely on the task at hand, and no physical contact was involved. If, as was the case with Julian Bashir, one's mind was not focused, the sphere itself would disappear. Dax told him that she had been trying to master the game for 140 years or so. (DS9: "A Man Alone")