Due to travel restrictions required during World War II, league president Frank Calder abolished the 10-minute overtime for regular season games in 1942 so that teams could catch their trains without delays. Regular season overtime did not return with the conclusion of the war, though playoff games continued until a winner was decided. Overtime was not re-introduced for the regular season until the 1983–84 season.
In 1943, the rules committee was looking for ways to increase the speed of the game and make it more entertaining. Rangers coach Frank Boucher proposed that the neutral zone be divided by a centre red line, and that teams be allowed to pass the puck out of the defensive zone into their half of the neutral zone. Previously, the league required that defensive players skate the puck out of their defensive zone, not permitting a pass across the blue line. Introduced in 1943–44, the new rule changed how the game was played. Where strong forechecking teams were previously able to pin their opponents in their own zone for minutes at a time, teams were able to create rushes up the ice by having defencemen pass to forwards across the blue line. Scoring increased 10% league-wide, and four of six teams topped 200 goals, the first teams to do so.
Stan Mikita inadvertently introduced the curved blade to the hockey stick in the early 1960s. Having cracked his blade during a practice and not wanting to go get another, Mikita shot the puck in anger. He noticed that the curve made by the crack caused the puck to behave differently. Mikita and Bobby Hull experimented with heating and bending the blade of their sticks to create different curves. Mikita went on to win four Art Ross Trophies as the NHL's leading scorer using a curved blade. He later said that he regretted the idea. "It's one of the worst inventions in hockey, because it eliminated the use of the backhand."
The NHL Amateur Draft was first held on June 5, 1963 at the Queen Elizabeth Hotel in Montreal, Quebec. It was created by Campbell as a means to distribute talent on a more even basis. To that point, teams had sponsored junior clubs directly, buying the rights to players on those teams. The first player selected in the 1963 draft was Garry Monahan, a 16-year-old player with the St. Michaels Juveniles. Monahan remains the youngest player ever selected in an NHL draft. The Entry Draft system did not fully replace the sponsorship system until 1969.