Directly as a result of the rat trick craze, the NHL amended its rules prior to the season to prevent a recurrence of this phenomenon and delays to the game that followed. Per the rule, if fans throw debris onto the ice, the referee can have the public address announcer warn the fans to stop. After a warning, the referee can then issue a delay of game penalty to the home team. The league, however, created a special exemption for articles "thrown onto the ice following a special occasion", specifically excluding the traditional tossing of hats onto the ice following a hat trick goal from subjection to the penalty.
