Canadian football 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: 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" generally refers to kicking plays, which typically involve a change in possession. Canadian football Canadian football () is a sport played in Canada in which two teams of 12 players each compete for territorial control of a field of play long and wide
Comparison of Canadian football and rugby union running backs, receivers, and quarterbacks have roles similar to backs in rugby. Because of the playing time, number of pauses, number of players and the nature of the game in general, rugby players will typically need higher physical endurance than Canadian football players while more short-term bursts of physical strength, power, and speed are required in Canadian football (amongst equivalent positions and weights). Collisions between players in rugby union tend to last significantly longer than Canadian football, in which collisions are more often "hits" in which the momentum of the player is enough to bring the other player to ground