Canadian football rules evolved from rugby in the late 1800's through the first half of the 20th century, separate from the development of the American game. The best source for a summary of the evolution is the first chapter of The Canadian Football League: The Phoenix of Professional Sports Leagues. Additional information can be found in older CFL books.
The CFL did not change any rules; Canadian football was not created recently from the tweaking of an existing rule book. Canadians developed the Canadian game from rugby over a long period at the same time other brands of football were being developed. The games influenced each other with the Canadian game having more attributes (size of field, number of players on the field, scoring) that resemble its rugby origins but introducing many modern rules and play styles that were adopted later elsewhere. The Canadian code was also slow to adopt new innovations such as the forward pass, which created a gulf in the development of the two football codes.
The two brands of North American football, despite geographic isolation (not the connected world of today) during the birth of the sports, have always had an influence on each other. Canadian football has faced the far greater influence in later periods as American players and coaches have come north to the CFL and its predecessors. Despite groups who have desired to do away with the differences in the game over the past 100 years and continue today, Canadian football rules have remained a unique brand and the world is better for the diversity.
If you would like to know more about the origins and codification of football (soccer), rugby, Canadian and American football, and the other offshoots, see Mike Roberts' book The Same Old Game: The True Story of the Origins of the World’s Football Games Vol. 1 and Vol. 2. The last two chapters of the second volume deal with the "early development of football in Canada, and how and why the game shifted from British rugby towards American football, but also explores Canada’s influence on the American game".
The CFL field is 65 yards wide by 150 yards long (110 yards between the goal lines plus two 20-yard end zones). Up to 1985 the field was 160 yards long. The end zones were 25 yards each until the 1986 season when they were reduced to 20 yards. The field is divided into two 55-yard halves, so centre field is at the 55-yard line.
The goal posts in the CFL are situated on the goal line. Good necked or single-shaft wishbone goal posts were first introduced in the CFL in 1966.
A CFL game is 60 minutes of playing time and takes about three (3) hours to complete (the Grey Cup championship is the exception, due to the halftime show and other factors it can take up to four (4) hours).
There are two halves, each consisting of two quarters for a total of four (4) quarters of 15 minutes each in a CFL game. Halves and quarters are self-explanatory, they represent dividing the game by two (or in half) and four (or in quarters). Overtime, if necessary, is not timed and can take up to 30-45 minutes of real time to complete the maximum two possessions per team in the Regular Season.
Broadcasters will refer to the "long" quarters in a CFL game when in fact all quarters are the same length. What they are referring to, however, is that the second and fourth quarters have different time in (clock starting) rules in the last three minutes, allowing more plays to be executed in those quarters, therefore they are considered "longer".
The CFL halftime break is 14 minutes long as designated in Article 2 of Section 7 — Starting & Timing of Rule 1 — Conduct of the Game of the Official Playing Rules of the Canadian Football League. This was changed from 15 minutes in 1988. Additional timing specifics are prescribed in Section K (page 17) of the CFL Regulations, which stipulate a 140 second break at the conclusion of the first and third quarters and the lengths of time-outs.
There is a 20-second play clock in the CFL. From the time the ball is set and time is blown in by the referee, there is 20 seconds for the offence to put the ball in play or be penalized for a time-count violation. Complete rules on the starting and stopping of the play clock are found in Rule 1, Section 7 of the CFL Rulebook.
The number of plays executed in a CFL game varies from game to game (a range of 135-175 plays per game). The average number of plays, including kickoffs, converts and punts is between 150-160 plays per game. In a game balanced between the two teams this would result in approximately 80 plays per team and about 55-60 offensive plays per team. Overtime games can add 20 or more plays to a game depending on whether a second possession is needed to decide the game and in how many plays both teams score in.
In 2015, the average (mean) number of plays over all regular season games including any extra plays in overtime was 154.3 with a minimum of 137 and a maximum of 173. The median was 153 plays and the mode was 150 plays per game.
If we assume the average play takes about six to seven seconds of clock time from snap to whistle and multiply that by 154 plays in a game, we get 924 to 1,078 seconds or 15:24 to 17:58 minutes of actual playing time in the average game. In a 60 minute game, that is 25.6% to 29.9% of the time executing plays. Other factors such as scoring, penalties, turnovers, changes of possession will affect these numbers. Beyond the snap of the ball to the whistle, there is a lot of other activity in Canadian football, from pre-snap motion (and the waggle), to contact through the echo of the whistle to getting up and running back to the huddle or on and off the field not included in play time.
Starting in 2013 each team receives two (2) time outs per game, but are only allowed to use one within the 3-minute warning of the second half. The full definition of time outs are found in Rule 1, Section 7, Article 5 of the CFL Rulebook. Prior to 2013 each team was allowed one (1) time out per half in a CFL game and time outs were not carried over if not used.
Any player on the field or the Head Coach may call a time out by notifying any official on the field. Time outs are 30 seconds in duration and stop the game clock until the next snap.
Overtime does not provide for any additional time outs.
The CFL employs a two-possession overtime (shootout style or modified Kansas Plan) where teams alternate possessions from the 35-yard line and attempt to outscore their opponents in a series in order to win the game. Starting in 2010, teams are required to attempt a two-point convert after scoring a touchdown on any possession. In the regular season, a tied score after two possessions by each team results in a tie game and each team being awarded 1-point in the standings. The playoffs and Grey Cup feature the same overtime rules, however teams continue to play a series of possessions until a winner is decided.
The shootout format of overtime was introduced in 2000 with four possessions per team before a game would be declared a tie. This was reduced to two possessions in 2001. From 1986 to 1999 the format used was two 5-minute halves, non-sudden death.
Starting with the introduction of overtime, 2 points in the standings was awarded for a win and 1 point to each team for a tie. From 2000 to 2002, an extra point was awarded to a team that lost in overtime (2 points to the winner, 1 point to the loser, or 1 point each if tied after overtime). This change was repealed in 2003 and now the standard 2 points for a win and 1 point each for a tie is how points are awarded in the standings.
The rules surrounding video review and coaches challenges have grown complicated with changes and expansion occurring every year so I recommend you read the complete rules and not rely on this summary.
The rules governing Instant Replay in the CFL can be found in the rulebook. Effective August 26th, 2016, each team receives three challenges per game. If the challenge is unsuccessful, the team is charged (loses) a time-out. A team must have a time-out available in order to use a challenge. Teams receive two time-outs per game. In order to use their third challenge, teams must have been successful in their first and second challenges and have a time-out remaining.
The most recent changes removed the "free" challenge available to coaches. Previously, each team received two challenges per game and a third challenge if their first two challenges were successful and they had a time-out remaining. If a team was unsuccessful in their first challenge, there was no penalty except the availability of a third challenge. Unsuccessfully challenging a ruling with their second challenge cost a team a time-out and the availability of a third challenge. Challenging a play unsuccessfully with their third challenge also cost a team a time-out.
In the final three-minutes of regulation time and all overtime play, coaches may not challenge a play, though they may challenge a penalty provided they have a remaining challenge. Instead, reviews of plays will be initiated by the CFL replay command centre. Since 2012, all scoring plays are reviewed by the replay command centre. Starting in 2014, certain turnovers by fumble or interception are automatically reviewed by the command centre.
Only challengeable play types as defined in the rulebook can be reviewed. In 2014, pass interference penalty calls were included as challengeable plays. In 2016 this was expanded to all pass interference/illegal contact penalties and more as defined in Coach Reviewable Penalties.
Instant replay was introduced in 2006 and was performed by the head official on the sidelines for the 2006-2008 seasons inclusive. The current system of a central command centre was established in 2009.
The 2009 challenge and play review log was available from CFL.ca.
As of Labour Day weekend games in 2011, video-board operators are allowed to show replays while a play is under review. Since the move in 2009 to establish a central command centre for all challenges and play reviews rather than on the sidelines by the head referee, showing the replay in-stadium while in review has no possibility of influencing the call, hence the reversal of the guidelines introduced with the adoption of instant replay in 2006.
Prior to this directive to teams by the league in 2011, the Instant Replay overview page in the rulebook read "Video board operators are not permitted to show replays on the video board in the stadium while a review is in progress."
CFL memos to teams on the subject provide the following guidance:
Video board operators are not permitted to show replays on the video board in the stadium while a review is in progress. A review begins when the coach throws his challenge flag and ends when the Referee announces the result.
The following incidents must not be replayed on video boards under any circumstances: (a) Altercations between players. (b) Confrontations between game officials, players and/or coaches.
Common sense should prevail concerning replaying potential controversial officiating decisions. When a penalty has been called, no replays may be shown prior to the Referee announcing the penalty call... Discretion must be exercised by a club if a player’s injury is replayed, especially if the injury is severe.
There are seven (7) on-field officials and seven (7) sideline officials for a total of 14 officials to manage a CFL game. The titles of both on-field and sideline officials are defined in Rule 2 - Section 1 - Designation of Officials and their duties defined in Rule 2 - Section 2 - Jurisdiction & Duties of Officials of the Official Playing Rules for the Canadian Football League.
Rule 1, Section 11, Article 1 of the CFL Rulebook defines the size of the team bench area and who is allowed in this area. The bench area is set back six feet from the sidelines and substitute players, coaches, doctors, trainers, equipment assistants and water carriers are allowed to be in this area. Only coaches are allowed between the bench area and sideline. Coaches are not allowed on the field at any time except with the permission of the referee. The penalty available to officials for violations of this rule is a loss of 10 yards.
Interference with play by accredited bench personnel is covered by Rule 1, Section 12, Article 1 of the CFL Rulebook. The penalty can award a touchdown to the opponent and disqualify the offending player from the game.
Interference with play by a non-accredited person on the sidelines is covered by Rule 1, Section 12, Article 2.
Players must get one foot to touch down in the field of play before stepping out of bounds in the CFL when receiving a ball, whether a pass, kick or fumble. This comes into play if they leap for the ball and acquire it in midair. When they land, one foot must touch down in the in bounds area before any part of their body touches down in the out of bounds area. This applies in all areas of the field, including end zones and the normal field of play. Full rules on out of bounds are found in Rule 1, Section 9 of the CFL rulebook.
Out of bounds is defined as any part of the body touching the white stripe or beyond on the external boundary of the field. All parts of the foot must be in bounds (not touching the stripe) for the foot to be considered in bounds.
For the goal line, the leading part of the stripe must be broken by any part of the ball (not the whole ball) for the goal line to be considered broken and a touchdown scored. Imagine an invisible plane (a flat surface on which a straight line joining any two points on it would wholly lie) extending upwards from the front of the goal line stripe across the width of the field. If the ball touches or breaks this plane, the ball is considered in the end zone and a touchdown scored. See Rule 3, Section 2, Article 1 of the CFL rulebook.
The power of the commissioner to fine and suspend players, coaches, employees, officials or team executives is granted in Section 10.06 of the CFL Constitution as amended in Section 14.02 of the current CBA. Discipline can be imposed for "… breach of any requirement of the Constitution, By-laws, Regulations or any proper orders or for conduct, actions or behaviour that, in the opinion of the Commissioner, brings disrepute to the League or the game of football."
The maximum league fine shall not exceed $25,000 or one-half (½) of the player's regular season game cheque. To reach the $25,000 limit a player would have to have a $900,000 contract (excluding bonuses). There is no maximum suspension length defined. Section 10.06 of the Constitution grants the commissioner the ability to suspend indefinitely or for life any player or person associated with the league or its member clubs who has bet on the outcome of a game as well as fine them a maximum of $5,000, cancel their contract and order their shares in any member club sold.
Article 21 of the CBA defines the rules surrounding fines and player discipline available to member clubs. Players may be fined a maximum of one-half their pay for a regular season game. Fines of $75 or less may be used by the players and coach for the benefit of all players on the club roster. Fines greater than $75 are to be collected by the member clubs, turned over to the CFL who in turn shall remit the total to the CFLPA. The CFLPA may use these monies for any purpose provided they report to the CFLPRC the use of the fines.
Based on this rule, teams may have varying levels of fines of $75 or less for infractions as decided by the head coach or players. Popular infractions for fines would be personal fouls in games, being late for practice or meetings, and other discipline related actions. While it is possible for a system to fine for every penalty a player commits, it is more likely imposed for face-masking, objectionable conduct, disqualification and other major penalties.
The non-offending team has the option, per Rule 8, Article 3 of the rulebook, to decline a penalty "… to take any advantage of position, score, down, time, etc." For example, if a defensive team was offside, which results in a 5-yard penalty and down repeated, but the play resulted in a 20-yard gain for the offence, the offence would decline the penalty and take the gain that resulted from the play as it is greater and provides a new set of downs.
There are instances when it may be advantageous to accept the penalty rather than the gain, such as when the penalty awards an Automatic First Down. Therefore it is up to the coach to determine the best course for the team in accepting or declining a penalty. There are also instances where teams are not given the option to decline a penalty, such as the rules in Rule 4 Scrimmage.