The player controls a five-man football team, actively controlling one team member at a time, with the computer controlling the rest. As in traditional American football, the player's team must score more points than the opponent's team within the time limit of the game. The game consists of four quarters, each a simulated 15 minutes in length, and takes place on a horizontally scrolling 100-yard simulated football field.
Player 1 always starts the game on offense and receives the opening kick-off from Player 2; at the start of the second half, Player 2 will receive the kick-off from Player 1. NFL Football is played in the same basic manner as a regulation game of football, with the offense being given four downs to advance the ball a minimum of ten yards before losing possession of the football to the opposing team. At the start of each down, the players use their controller's keypad to input a formation and a play for that down; descriptions and diagrams of the plays were printed in the game's instruction manual and not visible on-screen. When both players have entered their formations, play resumes.
The player on offense generally controls the team's quarterback unless the ball is handed off to a running back or passed to an eligible receiver. In the former case, control immediately switches to the running back. In the latter case, control switches to the intended receiver, who must maneuver to catch the ball before it goes out of bounds or is intercepted by the defense. On defense, the player controls the "captain,"[3] roughly in the position of a safety. All defensive team members are capable of tackling the ball carrier, but only the player-controlled team member may attempt to intercept a pass.
Games whose scores are tied at the end of the fourth quarter of play end as ties, with no overtime period.