VANCOUVER, British Columbia -- After several embarrassing officiating controversies overshadowed the Stanley Cup playoffs, the National Hockey League significantly increased the scope of its referees' video review capabilities and added a third category to its coach's challenges at Thursday's general managers meeting in Vancouver.

"We view this as evolutionary. We don't want it to be perceived as an overreaction," NHL commissioner Gary Bettman said. "The increased use of video replay is something we've considered and discussed over time, and at this point and time we think it was the appropriate response to what we were seeing, coupled with our ability to do it."

That said, there are clear links from this "evolution" of the coach's challenge and video review to the controversial missed calls from the 2019 playoffs.

Referees who call major or match penalties -- not including those handed out for fights -- will now be required to use video review to either confirm the call or reduce the penalty to a two-minute minor if it's clear there was a mistake made on the severity of the penalty. They can consult any other on-ice official, but not the NHL's situation room.

"The referee is going to review the call using advanced technology, and has the discretion to confirm the call, hopefully in most cases, or reduce the call to a minor penalty. He will not have the discretion to eliminate or rescind the penalty," deputy commissioner Bill Daly said.

This rule change would cover plays like the controversial major penalty handed to Cody Eakin of the Vegas Golden Knights in their Game 7 loss to the San Jose Sharks, during the playoffs' opening round. The Sharks, down 3-0, rallied with four goals on the subsequent five-minute major penalty and eventually won the game in overtime. The NHL apologized to the Golden Knights for the incorrect call, and the officials who worked the game did not again appear in the postseason.

The NHL is also empowering its referees to review double-minor penalties for high-sticking, in which one teammate's stick hits another teammate or a player's own stick strikes him in the head, or "friendly fire" situations as Bettman termed them. These reviews will not be required, but rather will be discretionary. As with the major penalty reviews, there will be no consultation with the NHL situation room.

In addition to interference on the goaltender and offside calls preceding goals scored, NHL coaches can now challenge plays in the offensive zone that should have resulted in play being stopped before a goal was scored.

That includes "black or white" plays like the missed hand pass that helped the Sharks win Game 3 of the Western Conference finals in overtime, and the puck that bounced off the netting that resulted in a Columbus Blue Jackets goal in the Eastern Conference semifinals. It would also cover plays like the puck being hit with a teammate's high stick before a goal.

There are no time limitations on these challenges, and there's no mandate that a team must maintain possession of the puck during the missed call. The only restriction is that the puck must remain in the attacking zone through the missed stoppage and the goal being scored.

Bettman was clear that this new category of coach's challenge would not cover "missed penalties," such as the uncalled trip by St. Louis Blues forward Tyler Bozak on Boston's Noel Acciari in Game 5 of the Stanley Cup Final that led to a critical goal for the Blues.

The St. Louis Blues weren't happy with the officials' apparent miss of an illegal hand pass in an overtime loss during the Western Conference final. The NHL announced changes to its video review system for next season on Thursday. Dilip Vishwanat/Getty Images

"We're not prepared to go there in terms of the game right now. That would be something that wouldn't be terribly productive and would be terribly disruptive," Bettman said.

The NHL also removed the limitations on how many times teams can use a coach's challenge during the game. Now, teams can challenge as many scoring plays as they wish. An unsuccessful first challenge would result in a minor penalty for delay of game. Any subsequent unsuccessful challenges would result in a double minor for delay of game. Currently, coaches need a timeout in order to challenge a goalie interference play.

"We don't want lots and lots of challenges. We don't want to disrupt the flow of the game," Bettman said. "We only want challenges where it's crystal clear that an egregious mistake has been made."

The situation room in Toronto will continue to be responsible for initiating video review in the final minute of regulation and overtime as well as continue to have final authority over all coach's challenge video review decisions with input and consultation from both the on-ice officials and a former official staffed in the situation room.

In other NHL rules changes approved by the league's general managers, after being suggested by the NHL's competition committee:

Helmets: Subject to further consultation with the NHL Players' Association on precise language, a player on the ice whose helmet comes off during play must (a) exit the playing surface, or (b) retrieve and replace his helmet properly on his head (with or without his chin strap fastened). A player who is making a play on the puck or who is in position to make an immediate play on the puck at the time his helmet comes off, shall be given a reasonable opportunity to complete the play before either exiting the ice or retrieving and replacing his helmet. Failure to comply with the above will result in a minor penalty being assessed on the offending player. A player who intentionally removes an opponent's helmet during play shall be assessed a minor penalty for roughing.

Line changes for defensive team: The defensive team will not be permitted a line change when a goalie freezes the puck on any shot from outside the center red line. Similarly, if the actions of a skater of the defensive team cause a stoppage by unintentionally dislodging the net from its moorings, the defensive team will not be permitted to make a line change. In both of these instances, the offensive team will have the choice of which end zone dot the faceoff will take place.

Faceoffs following an icing and to begin a power play: Following an icing as well as at the beginning of any power play, the offensive team will have the choice of which end zone dot the faceoff will take place.

Awarded goal: If the goalpost is deliberately displaced by a goalkeeper during the course of a "breakaway," a goal will be awarded to the nonoffending team.

Puck out of bounds: When the attacking team is responsible for the puck going out of play in the attacking zone, in all instances, the faceoff will be conducted at one of the two faceoff dots in the attacking zone.

Bettman said there was a discussion about changing the puck-over-the-glass rule that currently leads to a delay of game penalty, but said that inconsistency of camera coverage from arena to arena makes it difficult to tweak it.