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 substituted off for any reason except for minor bleeding is not allowed to return to the game (with the possible exception of front-row forwards). Rugby teams may make up to eight substitutions. There are fifteen players on the pitch at all times. Players who are verified as bleeding by an independent medical official are sent to the "blood bin," where they can receive medical treatment, and replaced until they have stopped bleeding. Ejected players in Canadian football can be replaced with a substitute, while in rugby union ejection means the team must play a man down the remainder of the