In American

American football

American football is a sport played between two teams of eleven with the objective of scoring points by advancing the ball into the opposing team's end zone. Known in the United States simply as football, it may also be referred to informally as gridiron football. The ball can be advanced by...

 and Canadian football

Canadian football

Canadian football is a form of gridiron football played 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...

, a guard (G) is a player that lines up between the center

Center (American football)

Center is a position in American football and Canadian football . The center is the innermost lineman of the offensive line on a football team's offense...

 and the tackles on the offensive line of a football team.

The guard's job is to protect quarterback

Quarterback

Quarterback is a position in American and Canadian football. Quarterbacks are members of the offensive team and line up directly behind the offensive line...

 from the incoming defensive line and linebacker

Linebacker

A linebacker is a position in American football that was invented by football coach Fielding H. Yost of the University of Michigan. Linebackers are members of the defensive team, and line up approximately three to five yards behind the line of scrimmage, behind the defensive linemen...

s during pass plays, as well as creating openings (holes) for the running backs

Running back

A running back is a gridiron football position, who is typically lined up in the offensive backfield. The primary roles of a running back are to receive handoffs from the quarterback for a rushing play, to catch passes from out of the backfield, and to block.There are usually one or two running...

 to head through. Guards perform speed blocking and "pulling"—sprinting out in front of a running back in order to block for him. Guards are automatically considered ineligible receivers

Eligible receiver

In American football and Canadian football, not all players on offense are entitled to receive a forward pass. Only an eligible pass receiver may legally catch a forward pass, and only an eligible receiver may advance beyond the neutral zone if a forward pass which crosses the neutral zone is thrown...

, so they cannot intentionally touch a forward pass, unless it is to recover a fumble or is first touched by a defender or eligible receiver.

Right guards (RG) is the term for the guards on the right of the offensive line, while left guards (LG) are on the left.