2001
During the annual owners meeting, they voted to extend Instant Replay until the end of the 2003 season.  The vote to extend replay for three years was 25-5.  The replay system will continue to use the same rules used during the 1999 and 2000 seasons.  Players are now banned from wearing bandanas; which was passed by a majority of 30-1 votes. Bandanas will be allowed to be worn for medical reasons only.  Skullcaps are allowed as long as they bear the team logo and colors.  The quarterback will be protected more greater this season.  Taunting will also be enforced more strictly with 15-yard unsportmanlike fouls.   The momentum rule has been changed.  The change results that the ball given to the defensive team at the spot where it took possession even if the defensive player's momentum carried him backward into the end zone.  This rule also goes for interceptions, fumble recoveries and free kicks.  

2000
Instant replay returns for the second year in a row.  The rules will be the same as the 1999 season. (Coaches get two challenges per game; An unsuccessful challenge results in a lost time-out.  In the last two minutes of the each half and overtime, a "replay official" in the booth determines if a challenge is issued. The on-field referee makes the decision, with a 90-second time limit on the review)  "Offsides" will be enforced more strictly this season.  The receiving team also has the option if the Kicking team is offsides of accepting a 5 yard penalty or keeping the ball.

1999 
Instant replay returns with a challenge system. Coaches get two challenges per game. An unsuccessful challenge results in a lost timeout. In the last two minutes of the each half and overtime, a "replay official" in the booth determines if a challenge is issued. The on-field referee makes the decision, with a 90-second time limit on the review. Clipping is now illegal around the line of scrimmage -- just as it is on the rest of the field.

1998
The coin toss will be called before the coin itself is tossed. Tinted visors are banned from players' facemasks except for medical need. Offensive players will automatically be flagged for having 12 players in the huddle. No defensive player may flinch to cause the offensive team to false-start.

1997 
When a team fakes a punt and throws the ball downfield, pass interference calls on the two outside defenders who are actually trying to block a coverage man from getting downfield and might not even know the ball has been thrown, have been eliminated. No player is allowed to remove there helmet while on the field unless there has been a time-out called.

1996 
Instant replay will be tested during the preseason in the nationally televised games. Three sideline variations will be tested, with the on-field officials reviewing the play -- no press box official. Each head coach was given a red flag to throw to indicate he wanted the play reviewed (max two reviews per half). The only plays subject to review are: Scoring plays. Sideline/end zone plays. Number of players on the field. The five-yard contact rule will be enforced more stringently. Hits with the helmet or to the head by the defender will be flagged as personal fouls and subject to fines. This is being done to protect the offense, particularly the quarterback.

1995 
There will be no instant replay. Previously there had been consideration in using instant replay for just the playoff games. A second proposal to allow teams three opportunities per game to challenge calls by officials was withdrawn from the vote. The emergency (third) quarterback may now enter the game in just the fourth quarter, regardless if the other two quarterbacks are able to play. This means that if the third string quarterback enters the game, the first and/or second quarterback may re-enter, unlike the past two seasons where the emergency quarterback would only play off the first two were unable to resume play. A receiver knocked out of bounds by a defensive player can now return to the field to make a play. Quarterbacks may now receive communication from the bench via a small radio transmitter in their helmets. This proposal was originally run on a test basis last year during the pre-season, but was scrapped.

1994 
There is now a 2 point conversion following touchdowns. The starting point of all kickoffs will be the kicking teams 30 yard line (moved back 5 yards). Kickoff tees used can be no more than one inch in height (previously 3 inches) A neutral zone infraction has been clarified. Officials are to immediately blow their whistles whenever a defender enters the neutral zone causing the offensive player's directly opposite to move. This is considered a penalty on the defense. If there is no immediate react ional movement by the offensive player's, there is no foul. (The neutral zone is defined as the space the length of the ball between the offense and defense line of scrimmage) All field goals attempted and missed when the spot of the kick is beyond the 20 yard line, the defensive team taking possession will get the ball at the spot of the kick. On any field goal attempted and missed with the spot of the kick is on or inside the 20, the ball will go to the defensive team taking possession at the 20. The 11 players on the receiving team are prohibited from blocking below the waist during a play in which there is a kickoff, safety kick, punt, field goal attempt, or extra point kick with one exception: Immediately at the snap on these plays those defenders on the line of scrimmage lined up on or inside the normal tight end position can block low.

1988
A 45 second play clock was adopted.

1980
Players were prohibited from directly striking, swinging, or clubbing on the head, neck, or face. 

1979
No player may block below the waist during kickoffs, punts, and field-goal attempts. Crack back fouls were made illegal. The referee was now allowed to blow the play dead when the quarterback was in the grasp of a defensive player. On fourth down, or on any down inside the last two minutes of either half, only the fumbling player can recover the ball for a gain. If anyone else on the fumbling team recovers, the ball is returned to the spot of the fumble.

1978
A defender could only make contact of an offensive pass receiver prior to going downfield 5 yards.

1977
Rules changes were adopted to open up the passing game and to cut down on injuries. Defenders were permitted to make contact with eligible receivers only once; the head slap was outlawed; offensive linemen were prohibited from thrusting their hands to an opponent's neck, face, or head; and wide receivers were prohibited from clipping, even in the legal clipping zone.

1976
Two 30 second clocks were adopted.

1974
Sweeping rules changes were adopted to add action and tempo to games: one sudden-death overtime period was added for preseason and regular-season games; the goal posts were moved from the goal line to the end lines; kickoffs were moved from the 40- to the 35-yard line; after missed field goals from beyond the 20, the ball was to be returned to the line of scrimmage; restrictions were placed on members of the punting team to open up return possibilities; roll-blocking and cutting of wide receivers was eliminated; the extent of downfield contact a defender could have with an eligible receiver was restricted; the penalties for offensive holding, illegal use of the hands, and tripping were reduced from 15 to 10 yards; wide receivers blocking back toward the ball within three yards of the line of scrimmage were prevented from blocking below the waist.

1973
A jersey numbering system was adopted, for quarterbacks and specialists, 20-49 for running backs and defensive backs, 50-59 for centers and linebackers, 60-79 for defensive linemen and interior offensive linemen other than centers, and 80-89 for wide receivers and tight ends.

1972
The hash marks were now in the middle of the field.

1970
Players now had there names on the backs of there jerseys.

1969
Playoff formats were constituted. 

1962
The scoreboard clock becomes the official time piece and no player is allowed to grasp any players face mask.

1956

A rule added that states no player show grasp a face mask other than the ball carrier's. Using communication equipment was illegal. 

1955

When a player possessing the ball touches the ground with any part of his body except a hand or foot while in the grasp of a defender, then he is ruled down.

1951
No tackle, guard, or center would be eligible to catch a forward pass.

1950
Free substitution was constituted.

1948  
An artificial tee for a kickoff was now legal and plastic helmets were illegal.

1946
Substitutions were allowed to only 3 players during one given down and all forward passes that strike the goal posts become automatically incomplete.

1945
The hash marks were moved 10 yards from the original location; a little closer to the middle of the field.

1941
A "Sudden Death" overtime period was added in the event of the game being tied at the end of  regulation.

1933
Goal posts on the goal lines, and hash marks were added.

1912
A touchdown will now be 6 points instead of 5.

1909
A field goal will now be 3 points instead of 4.

1906
All forward passes are now legal. 

1904
Field goals will now be 4 points instead of 5.

1800's
A touchdown will now be 5 points instead of 4.