NFL Game Day is a game that approximates coaching an NFL football game by providing two different decks of card (offensive and defensive plays) that players use, based on the board positioning, to simulate play calling.
One player will be on offense and the other on defense, each player selects a play call from their hand of cards and they play them simultaneously. A comparison is done using a chart on each card, and the magnetic football is moved on the board accordingly.
For instance: It's 1st and 10 on the offensive players own 30 yard line. The offensive player chooses a passing play, and the defensive player chooses a run defense. The chart on the card indicates that the play results in a turnover. Now, the players change decks, and assume the other role.