NEW YORK (AP) — Blindside hits to the head are a thing of the past in the NHL.

The executive board of the players' union voted Thursday to accept a new temporary rule that will ban hits to the head against unsuspecting players. The decision takes effect immediately, starting with the league's 11 games tonight.

"We believe this is the right thing to do for the game and for the safety of our players," NHL commissioner Gary Bettman said in a statement. "The elimination of these types of hits should significantly reduce the number of injuries, including concussions, without adversely affecting the level of physicality in the game."

The rule prohibits "lateral, back-pressure or blindside hit to an opponent where the head is targeted and/or the principal point of contact." The league will have the power to review such hits and apply further discipline.

The union's representatives on the competition committee signed off on the ban Wednesday. It was then left to the union's board to accept or reject the recommendation.

The rule is in effect through this year's playoffs. The competition committee is expected to meet during the summer to create a permanent rule that will also include an on-ice penalty instead of solely punishment after the fact.

"We are encouraged by the league's recent willingness to explore on-ice rule changes as a means of reducing player injuries and have no doubt that by working together, a safer working environment can be established for all NHLPA members," the union said in a statement.

After Wednesday's recommendation by the players' association members on the competition committee to accept the ban, the union said its executive board would vote within two days. It acted swiftly Thursday to agree to the new rule.

The NHL board of governors unanimously approved the proposed penalty Tuesday. The league's general managers first proposed it this month.

Florida forward David Booth missed 45 games this season after getting hit by Philadelphia captain Mike Richards — a play that was legal at the time, but will no longer be tolerated under the new system.

An unpunished blindside hit by Pittsburgh's Matt Cooke against Boston's Marc Savard on March 7 also increased pressure to enact a new rule. Savard sustained a concussion that will likely sideline him for at least the rest of the regular season.

The GM meetings began the day after Savard was hit.