In Challenge Football players are taking the role of coaches in an "American" Football game. As coaches, each is deciding what plays to run in order to win the game. Plays commences with the selection of a play card by the defensive player. He/she installs a cover over this card such that the offensive player can only see the players on the line of scrimmage. A "shift" card must also be selected that gives the option of shifting the defensive line to either side for the play. The offensive player receives the play card and cover and must draw the offensive play on top of the clear holder. This could be a combination of runs, handoffs and passes. With the plays determined, the cover is removed, the shift card revealed and the path of the play is compared to the defensive positions. Where the path crosses a triangle is where the ball is downed. A touchdown is scored when a play is not downed on the field. Players are also attempting to make ten yards in four downs, as in football, to earn a first down. Random events include a roll every play to see if there is a penalty, and dice-rolling punting, kick off and field goal rules. After four quarters of fifteen plays each, the winner is the player with the most points. 3M Bookshelf Series.