Canadian football Canadian football is a form of gridiron football played almost exclusively in Canada in which two teams of 12 players each compete for territorial control of a field of play long and wide attempting to advance a pointed prolate spheroid ball into the opposing team ' s scoring area ( end zone ) . In Canada , the term football usually refers to Canadian football and American football collectively , or either sport specifically , depending on the context . The two sports have shared origins and are closely related , but have significant differences — in particular , 12 players on the field per team in Canadian football rather than 11 , and three downs per possession rather than four . The fewer number of downs in Canadian football results in less offensive rushing than in the American game . Rugby football in Canada had its origins in the early 1860s , and over time , the unique game known as Canadian football developed . Both the Canadian Football League ( CFL ) , the sport ' s top professional league , and Football Canada , the governing body for amateur play , trace their roots to 1884 and the founding of the Canadian Rugby Football Union . Currently active teams such as the Toronto Argonauts and Hamilton Tiger - Cats have similar longevity . The CFL is the most popular and only major professional Canadian football league . Its championship game , the Grey Cup , is the country ' s single largest sporting event and is watched by nearly half of Canada ' s population . Canadian football is also played at the high school , junior , collegiate , and semi - professional levels : the Canadian Junior Football League and Quebec Junior Football League are leagues for players aged 18 – 22 , many post - secondary institutions compete in Canadian Interuniversity Sport for the Vanier Cup , and senior leagues such as the Alberta Football League have grown in popularity in recent years . Great achievements in Canadian football are enshrined in the Canadian Football Hall of Fame . Other organizations across Canada perform senior league Canadian football during the summer . History . The first documented gridiron football match was a game played at University College , University of Toronto November 9 , 1861 on the present site of University College ( approximately 400 yards west of Queen ' s Park ) . One of the participants in the game involving University of Toronto students was ( Sir ) William Mulock , later Chancellor of the school . A football club was formed at the university soon afterward , although its rules of play at this stage are unclear . In 1864 , at Trinity College , Toronto , F . Barlow Cumberland and Frederick A . Bethune devised rules based on rugby football . However , modern Canadian football is widely regarded as having originated with a game of rugby played in Montreal , in 1865 , when British Army officers played local civilians . The game gradually gained a following , and the Montreal Football Club was formed in 1868 , the first recorded non - university football club in Canada . This rugby - football soon became popular at Montreal ' s McGill University . McGill challenged Harvard University to a game , in 1874 . Predecessors of the Canadian Football League include the Canadian Rugby Football Union ( CRFU ) , and the Canadian Rugby Union . The CRFU , original forerunner to the current Canadian Football League , was established in 1882 . League play . Canadian football is played at several levels in Canada . The professional league in which the sport is played is the eight - team Canadian Football League ( CFL ) , and its champion is awarded the Grey Cup , the oldest trophy in professional football . The CFL regular season begins in June , and playoffs are completed by mid - November . In cities with outdoor stadiums such as Calgary , Edmonton , Winnipeg , Montreal , Hamilton , and Regina , low temperatures and icy field conditions can seriously affect the outcome of a game . Amateur football is governed by Football Canada . At the university level , 27 teams play in four conferences under the auspices of Canadian Interuniversity Sport ; the CIS champion is awarded the Vanier Cup . Junior football is played by many after high school before joining the university ranks . There are 20 junior teams in three divisions in the Canadian Junior Football League competing for the Canadian Bowl . The Quebec Junior Football League includes teams from Ontario and Quebec who battle for the Manson Cup . Semi - professional leagues have grown in popularity in recent years , with the Alberta Football League becoming especially popular . The Northern Football Conference formed in Ontario in 1954 has also surged in popularity as College players that do not continue to or get drafted to a professional team but still want to continue playing football . The Ontario champion plays against the Alberta Football league champion for the " National Championship " . The Canadian Major Football League is the governing body for the semi - professional game . The field . The Canadian football field is long and wide with end zone s deep . At each goal line is a set of goalposts , which consist of two " uprights " joined by an crossbar which is above the goal line . The goalposts may be H - shaped ( both posts fixed in the ground ) although in the higher - calibre competitions the tuning - fork design ( supported by a single curved post behind the goal line , so that each post starts above the ground ) is preferred . The sides of the field are marked by white sidelines , the goal line is marked in white , and white lines are drawn laterally across the field every from the goal line . These lateral lines are called " yard lines " and are marked with the distance in yards from the nearest goal line , except for the yard line in the centre of the field , which is usually marked with a " C " for " Centre line " . " Hash marks " are painted in white , parallel to the yardage lines , at intervals , from the sidelines . On fields that have a surrounding running track , such as Commonwealth Stadium , Molson Stadium , and many universities , the endzones are often cut off in the corners to accommodate the track . Play of the game . Teams advance across the field through the execution of quick , distinct plays , which involve the possession of a brown , prolate spheroid ball with ends tapered to a point . The ball has two one - inch - wide white stripes . Kickoff . Play begins with one team place - kicking the ball from its own 35 - yard line . Both teams then attempt to catch the ball . The player who recovers the ball may run while holding the ball , or lateral throw the ball to a teammate . Stoppage of play . Play stops when the ball carrier ' s knee , elbow , or any other body part aside from the feet and hands , is forced to the ground ( a " tackle " ) ; when a forward pass is not caught on the fly ( during live play ) ; when a touchdown ( see below ) or a field goal is scored ; when the ball leaves the playing area by any means ( being carried , thrown , or fumbled out of bounds ) ; or when the ball carrier is in a standing position but can no longer move . If no score has been made , the next play starts from " scrimmage " . Scrimmage . Before scrimmage , an official places the ball at the spot it was at the stop of clock , but no nearer than 24 yards from the sideline or 1 yard from the goal line . The line parallel to the goal line passing through the ball ( line from sideline to sideline for the length of the ball ) is referred to as the line of scrimmage . This line is a sort of " no - man ' s land " ; players must stay on their respective sides of this line until the play has begun again . For a scrimmage to be valid the team in possession of the football must have seven players , excluding the quarterback , within one yard of the line of scrimmage . The defending team must stay a yard or more back from the line of scrimmage . Live play . On the field at the beginning of a play are two teams of 12 ( unlike 11 in American football ) . The team in possession of the ball is the offence and the team defending is referred to as the defence . Play begins with a backwards pass through the legs ( the snap ) by a member of the offensive team , to the quarterback or punter . If the quarterback or punter receives the ball , he may then do any of the following : Each play constitutes a " down " . The offence must advance the ball at least ten yards towards the opponents ' goal line within three downs or forfeit the ball to their opponents . Once ten yards have been gained the offence gains a new set of three downs ( rather than the four downs given in American football ) . Downs do not accumulate . If the offensive team completes 10 yards on their first play , they lose the other two downs and are granted another set of three . If a team fails to gain ten yards in two downs they usually punt the ball on third down or try to kick a field goal ( see below ) , depending on their position on the field . The team may , however use its third down in an attempt to advance the ball and gain a cumulative 10 yards . Change in possession . The ball changes possession in the following instances : Rules of contact . There are many rules to contact in this type of football . First , the only player on the field who may be legally tackled is the player currently in possession of the football ( the ball carrier ) . Second , a receiver , that is to say , an offensive player sent down the field to receive a pass , may not be interfered with ( have his motion impeded , be blocked , etc . ) unless he is within one yard of the line of scrimmage ( instead of in American football ) . Any player may block another player ' s passage , so long as he does not hold or trip the player he intends to block . The kicker may not be contacted after the kick but before his kicking leg returns to the ground ( this rule is not enforced upon a player who has blocked a kick ) , and the quarterback , having already thrown the ball , may not be hit or tackled . Infractions and penalties . Infractions of the rules are punished with " penalties " , typically a loss of yardage of 5 , 10 or 15 yards against the penalized team . Minor violations such as " offside " ( a player from either side encroaching into scrimmage zone before the play starts ) are penalized five yards , more serious penalties ( such as holding ) are penalized 10 yards , and severe violations ( such as face - masking ) of the rules are typically penalized 15 yards . Depending on the penalty , the penalty yardage may be assessed from the original line of scrimmage , the spot the violation occurred ( for example , for a pass interference infraction ) , or the place the ball ended after the play . Penalties on the offence may , or may not , result in a loss of down ; penalties on the defence may result in a first down being automatically awarded to the offence . For particularly severe conduct , the game official ( s ) may eject players ( ejected players may be substituted for ) , or in exceptional cases , declare the game over and award victory to one side or the other . Penalties do not affect the yard line which the offence must reach in order to reach first down ( unless the penalty results in a first down being awarded ) ; if a penalty against the defence results in the first down yardage being attained , then the offence is awarded a first down . Penalties may occur before a play starts ( such as offsides ) , during the play ( such as holding ) , or in a dead - ball situation ( such as unsportsmanlike conduct ) . Penalties never result in a score for the offence . For example , a point - of - foul infraction committed by the defence in their end zone is not ruled a touchdown , but instead advances the ball to the one - yard line with an automatic first down . For a distance penalty , if the yardage is greater than half the distance to the goal line , then the ball is advanced half the distance to the goal line , though only up to the one - yard line ( unlike American football , in Canadian football no scrimmage may start inside either one - yard line ) . If the original penalty yardage would have resulted in a first down or moving the ball past the goal line , a first down is awarded . In most cases , the non - penalized team will have the option of " declining " the penalty ; in which case the results of the previous play stand as if the penalty had not been called . One notable exception to this rule is if the kicking team on a 3rd down punt play is penalized before the kick occurs : the receiving team may not decline the penalty and take over on downs . After the kick is made , change of possession occurs and subsequent penalties are assessed against either the spot where the ball is caught , or the runback . Kicking . Canadian football distinguishes three ways of kicking the ball : On punts and field goal attempts ( but not kickoffs ) , members of the kicking team , other than the kicker and any teammates who are onside ( behind the kicker at the time of the kick ) , may not approach within five yards of the ball until it has been touched by the receiving team . Scoring . The methods of scoring are : Resumption of play . Resumption of play following a score is conducted under procedures which vary with the type of score . Game timing . The game consists of two 30 - minute halves , each of which is divided into two 15 - minute quarters . The clock counts down from 15 : 00 in each quarter . Timing rules change when there are three minutes remaining in a half . A short break interval occurs after the end of each quarter ( a longer break at halftime ) , and the two teams then change goals . In the first 27 minutes of a half , the clock stops when : The clock starts again when the referee determines the ball is ready for scrimmage , except for team time - outs ( where the clock starts at the snap ) , after a time count foul ( at the snap ) and kickoffs ( where the clock starts not at the kick but when the ball is first touched after the kick ) . In the last three minutes of a half , the clock stops whenever the ball becomes dead . On kickoffs , the clock starts when the ball is first touched after the kick . On scrimmages , when it starts depends on what ended the previous play . The clock starts when the ball is ready for scrimmage except that it starts on the snap when on the previous play The clock does not run during convert attempts in the last three minutes of a half . If the 15 minutes of a quarter expire while the ball is live , the quarter is extended until the ball becomes dead . If a quarter ' s time expires while the ball is dead , the quarter is extended for one more scrimmage . A quarter cannot end while a penalty is pending : after the penalty yardage is applied , the quarter is extended one scrimmage . Note that the non - penalized team has the option to " decline " any penalty it considers disadvantageous , so a losing team cannot indefinitely prolong a game by repeatedly committing penalties . Overtime . In the CFL , if the game is tied at the end of regulation play , then each team is given an equal number of chances to break the tie . A coin toss is held to determine which team will take possession first ; the first team scrimmages the ball at the opponent ' s 35 - yard line and advances through a series of downs until it scores or loses possession . If the team scores a touchdown , starting with the 2010 season , it is required to attempt a 2 - point conversion . The other team then scrimmages the ball at the same 35 - yard line and has the same opportunity to score . After the teams have completed their possessions , if one team is ahead , then it is declared the winner ; otherwise , the two teams each get another chance to score , scrimmaging from the other 35 - yard line . After this second round , if there is still no winner , during the regular season the game ends as a tie . In a playoff or championship game , the teams continue to attempt to score from alternating 35 - yard lines , until one team is leading after both have had an equal number of possessions . In Canadian Interuniversity Sport football , for the Uteck Bowl , Mitchell Bowl , and Vanier Cup , the same overtime procedure is followed until there is a winner . Players . Offence . The offensive positions found in Canadian football have , for the most part , evolved throughout the years , and are not officially defined in the rules . However , among offensive players , the rules recognize three different types of players : Specific offensive positions include : Defence . The rules do not constrain how the defence may arrange itself ( other than the requirement that they must remain one yard behind the line of scrimmage until the play starts ) . Special teams . " Special teams " generally refers to kicking plays , which typically involve a change in possession . Bibliography . Stebbins , Robert A . ( 1993 ) " Canadian Football : The View from the Helmet " . Toronto , ON : Canadian Scholars Press .