A mandatory restricts the path the disc may take to the target. A disc must pass the correct side of the mandatory before the hole is completed. A disc has passed the mandatory once it establishes a position beyond the mandatory line.
The mandatory line is the line marked by the director or course designer to indicate when a disc has passed or missed the mandatory.
If no line has been marked, the mandatory line is defined as a straight line through the mandatory, perpendicular to the line connecting the mandatory to the previous mandatory, or if there is no previous mandatory, the tee.
In the case of a double mandatory when no line has been marked, the mandatory line is the straight line connecting the two mandatories, and extends beyond them in both directions.
A throw has missed the mandatory if it passes the incorrect side of the mandatory from the direction of the tee, and establishes a position completely beyond the mandatory line.
A throw that has missed the mandatory results in a one-throw penalty. The next throw shall be made from the drop zone, as designated for that mandatory.
If no drop zone has been designated, the player shall play from the previous lie.
If, after a mandatory has been passed, a subsequent throw crosses the mandatory line on the correct side but in the reverse direction, the mandatory has no longer been passed. The player must still pass the mandatory on the correct side. A line connecting the lies for the hole must pass to the correct sides of all mandatories for the hole.
The nearest mandatory which has not yet been passed is considered to be the target for all rules related to marking the lie, stance, obstacles, and relief, if the line of play does not pass to the correct side of that mandatory.
