The Players

Most football players have highly specialised roles. At the college and NFL levels, most play only offense or only defense.

Offense

• The offensive line (OL) consists of five men (two offensive tackles (OT), two guards (G), and a centre (C)) whose job is to protect the passer and clear the way for runners by blocking members of the defense. All plays begin with the centre handing the ball backwards between their legs, or snapping it, to a teammate, usually the quarterback.
• The quarterback (QB) receives the ball on most plays. They then generally hand or toss it to a running back, throw it to a receiver or run with it themselves.
• Running backs (RB) and fullbacks (FB) line up behind or beside the QB and specialise in rushing with the ball (especially RB's). They also block (especially FB's), catch passes and, on rare occasions, pass the ball to others.
• Wide receivers (WR) line up near the sidelines. They specialise in catching passes.
• Tight ends (TE) line up outside the offensive line. They can either play like wide receivers (try to catch passes) or like offensive linemen (protect the QB or create spaces for runners).

Defense

• The defensive line (DL) consists of three to five players (two defensive ends, one or two defensive tackles (DT), and possibly one nose guard (DT)) who line up across from the offensive line. They try to tackle the running backs before they can gain yardage or the quarterback before they can throw a pass.
• At least four players line up as defensive backs (DB). They may be cornerbacks (CB), free safeties (FS), or strong safeties (SS). They cover the receivers and try to stop pass completions. They occasionally rush the quarterback.
• The other players on the defense are known as linebackers (LB). They line up between the defensive line and backs and may either rush the quarterback or cover receivers and/or running backs.

Special Teams

The units of players who handle kicking plays are known as special teams. Special-teams players include the punter (P), who handles punts, and the kicker or placekicker (K or PK), who kicks off and attempts field goals and extra points. Field goal and extra point attempts also require a holder who receives the ball from the centre and holds it in a position that allows the kicker to easily kick the ball.