Differences between American and Canadian Football

Despite the fact that American football and Canadian football originated from the same game, they still developed their own distinctive characteristics over time. Below are the most striking features by which we can distinguish the origin of the game.

The tries in the USA
Contrary to Canadian Football and its 3 tries to go through 10 yards on each play, American Football, both at the amateur civic level and at the high school level (Middle School, Junior High School & High School), at the university level (College) and at the professional level (NFL, NFL Europe & Arena Football League), allows 4 tries to go through these same 10 yards on each play series.
12th player on the field in Canada
On offence, the 12th player (Canada) is usually a 2nd insert receiver and, on defence, a 2nd defensive back, rather than a 3rd cornerback.
Single (1 point) on a failed punt/kickoff/placement
The single in Canadian Football on a punt or kickoff, awarded when the returner cannot get the ball out of his own zone, is replaced in American Football (USA) by an automatic put back of the ball by the ball receiving team at their own 20-yard line. Likewise, on a fumble (USA), the receiving team automatically regains possession of the ball at the line of scrimmage of the fumble.
5-Goal circle protection on a punt
The 5 yards circular radius protection around the kick returner (partial immunity) in Canadian Football is replaced in the USA by the ability for the same kick returner to request immunity (full) by raising an arm in the air before catching (but not dropping) the ball or to simply let the ball roll and be “frozen” at the end of the run by the kicking team.
Field size
It is also worth noting that the American and Canadian versions’ field sizes are slightly different. For example, the NFL uses a 100-yard field, while Canada is used to playing on a 110-yard field.