X01 is a game in which each player starts with a set number of points and takes turns throwing three darts to reduce the number of points. The total score of the darts thrown is subtracted from the points, and the player who gets exactly 0 points in the end wins.
However, the last throw to make 0 points must be in the double area (including double bull). If the score falls below 0 points, if there is only 1 point remaining, or if the final score is not a double even if it reaches 0 points, it will be considered a "burst" and the score for that round will be invalidated and the score will return to the state before the round started.