Ko is a Japanese word adopted into English usage. It is originally and primarily used to in the game of Go, but can be used for other games as well. Ko, sometimes translated as Eternity, describes a situation in a board game where the same scenario or state of the game is being repeated. While this may be advantageous to one player to keep the game from ending, it would generally be considered rude or annoying and a rule prohibiting Ko can be useful. This rule effectively prohibits a player from recreating the same board position more than once resolving the situation.