Fullback (sports position)

Association football (soccer)

In association football the full-back (commonly left-back or right-back) is a defender stationed on the flank. Traditional duties include stopping opposing wingers, marking crosses and protecting the penalty area. Modern full-backs often join attacking phases, making overlapping or underlapping runs to provide width and deliver crosses. Variants include the more attacking wing-back in formations such as 3-5-2 and the "inverted" full-back who moves into midfield to help possession play. Famous stylistic examples include the attacking Brazilian full-backs who combined pace and crossing ability.

American football

In American football the fullback is an offensive back who lines up behind or beside the quarterback and primarily blocks for the ball carrier or the quarterback. A fullback can also act as a short-yardage runner, a lead blocker, or a pass catcher out of the backfield. This role has evolved: many modern offenses emphasize passing and use smaller, faster backs or hybrids (H-backs), but the position still exists in goal-line and power-running situations and in teams that value a strong lead blocker for the running game that protects the quarterback.

Rugby and other codes

In rugby union and rugby league a fullback is the player positioned deepest in defense, often the last line against opposition breaks. Responsibilities typically include fielding kicks, launching counterattacks, and covering defensive gaps. The role demands safe handling, good positional sense and kicking ability.

Roles, evolution and notable distinctions

• Defensive vs. offensive: In soccer and rugby the fullback is mainly defensive with attacking support, while in American football the fullback is primarily an offensive blocker and short-yardage weapon.
• Tactical evolution: Across codes the position has adapted to changes in formations and playing style — from purely defensive to multifunctional, hybrid and more attack-oriented roles.
• Physical and technical traits: Effective fullbacks often combine stamina, awareness, tackling, crossing or kicking skills, and the ability to read the game.

Understanding the fullback position requires viewing each sport’s tactical context: the same name covers distinct responsibilities shaped by rules, formations and strategic trends.