Rule 6.3 Ball Used in Play of Hole
Rule 6.3c THE WRONG BALL
A player must not make a stroke at a Wrong Ball. The stroke does not count and in Stroke Play the player must correct the mistake under the Rules by playing the right ball from its original spot or by taking relief under the Rules.
In Match Play the penalty is Loss of Hole. If the player and opponent play each other’s ball during the play of a hole, the first to make a stroke at a Wrong Ball gets the General Penalty Loss of Hole. If it is not known which Wrong Ball was played first, there is no penalty and the hole must be played out with the balls exchanged.
In Stroke Play the player must correct the mistake by continuing to play with the original ball by playing it as it lies or taking relief under the Rules.
The stroke made with the Wrong Ball and any more strokes before the mistake is corrected (including strokes made and any penalty strokes solely from playing that ball) do not count. The penalty is the General Penalty - 2 Strokes.
If the player does not correct the mistake before making a stroke to begin another hole or, for the final hole of the round, before returning his or her scorecard the player is Disqualified.
In Stroke Play, if you hit a Wrong Ball, you must go back and try and find the right ball before teeing from the next teeing area. If you searched for 2 minutes before playing the Wrong Ball you have only 1 more minute to search. If you do not find your original ball you have to go back to where you played the previous shot under Stroke and Distance. Total penalty strokes would then be 3 – 2 penalty strokes for playing the wrong ball and one penalty stroke for stroke and distance.