ORLANDO, Florida -- Pro football as we have come to know it has not undergone any major metamorphosis, even though NFL owners approved several rules changes designed to promote offensive efficiency.


The two-point conversion, for years a staple of college football, was approved for use in the National Football League on Tuesday, and five other moves were also overwhelmingly adopted, all in hopes of reviving offenses that have faced increasing struggles in recent years.


In addition to the two-point conversion -- approved by a 23-4 vote (the San Diego Chargers were not present) -- owners adopted the following rules:


?Kickoffs have been moved back from the 35 to the 30 in an effort to promote more returns and give offenses better field position at the start of drives.


?Kickers will only be allowed to use a 1-inch tee. The old rules allowed tees of up to 3 inches. The measure is designed to cut down on kickers attempting to pop the ball up, which often forces the return team to call for a fair catch and prevent a return.


?Missed field goals beyond the 20-yard line will now result in the opposing team taking over at the spot of the kick instead of the line of scrimmage, a difference of about 7 yards.


?Defensive players will be watched more closely when they guard eligible receivers.


?Offensive tackles will be allowed to set up about 2 feet further back from the line of scrimmage to get a head start on pass-rushing defenders. Crowd noise often prohibits the tackles from hearing the quarterback's signals.