National Football League players will be penalized for using the crown of their helmet against defenders and quarterbacks figure to fumble more often under rule changes adopted Wednesday.
The NFL club owners meeting resulted in an end to the controversial "tuck rule" involving passers and gave a nod to a head safety move in the wake of concussions becoming concerns both for active players and for long-term impact.
"I think we made some very significant progress on both those matters," NFL commissioner Roger Goodell said.
New England and Washington, each with a star quarterback in Tom Brady and Robert Griffin III respectively, abstained from the "tuck rule" vote, which now says that if a quarterback starts to bring the ball back to his body while trying to throw, it will be ruled a fumble rather than an incomplete pass.
The rule was famously applied in a 2001 playoff game where Brady lost the ball but the play was ruled an incomplete pass rather than a fumble and New England defeated the Oakland Raiders to advance to the Super Bowl.
"Adios Tuck Rule," tweeted the Raiders.
Running backs will not be able to lower their head and drive the helmet into opponents under the new helmet safety rule, a 15-yard penalty arising from any player using the crown of his helmet in such a way against an opponent.
That rule brought about the most debate, much of it over concerns about how the rule would be handled by referees.
"This is a pretty major change but one they think will be adapted to well by players," said Rich McKay, chairman of the competition committee.
The NFL also voted to limit the formations kick rushing defensive units may use and ordered a 15-yard penalty for blockers who do "peel back" blocks, ones used mainly on screen passes or plays to the sides of the line of scrimmage.