At the highest level of play in the NFL and NCAA, the one constant in all formations is the offensive line, consisting of the left and right tackle, left and right guard, and a center. These five positions are often referred to collectively as the "line", and have the primary role of blocking. By rule there must be two additional players on the line of scrimmage called Ends. These players are eligible receivers and may play near the linemen (tight ends) or farther away (split end or wide receiver). Most teams play additional players near (but still off) the line of scrimmage to act as extra pass receivers.
Of the four players behind the line, one is always the quarterback (defined as the player who receives the ball from the center), except in the Wildcat formation. The quarterback has four options once he receives the ball:
- He may keep the ball and run with it
- He may hand or pitch the ball laterally or backwards to another player, who may then run or throw a forward pass
- He may throw a forward pass to an eligible receiver
- He may punt the ball to the other team
The three other backs can be half backs, (who primarily carry the ball), fullbacks, (who primarily block), or they can play near (but not on) the line of scrimmage to act as extra tight ends or wide receivers. A tight end that fills the role as the 4th back is often called an "H-Back" and a wide receiver that fills that role is sometimes known as a "flanker" or a "slot" receiver (depending on where he lines up). Most formations have a "strong" side (the side with the tight end, or the side with more players) and a "weak side" (the side opposite the tight end, or the side with fewer players).
Below are the most common and historically significant offensive formations, along with descriptions and diagrams to display each. In each case, the diagrams will use the following symbols:
- QB = quarterback (the player who receives the snap to start the play)
- C = center (always the player who snaps the ball)
- G = guard
- T = tackle
- TE = tight end (also for H-back)
- WR = wide receiver (split end, flanker or slot receiver)
- HB = half back (the primary ball carrier)
- FB = full back (the primary blocking back)
This list is not exhaustive; there are hundreds of different ways to organize a team's players while still remaining within the "7 on the line 4 in the backfield convention".