From the NFL’s Policy Manual for Member Clubs: Volume II, the operation of retractable roofs are subject to the ground rules (for once, meant literally) set by the NFL. Retractable roofs are installed in the home fields of the Cardinals, Colts, Cowboys, and Texans.
One and one-half hours prior to kickoff, the home team will have the authority to determine if the roof should be open or closed for the game. The home club may choose to open the roof for some games and not for others. In the event a game is started with the roof in the open position and it is closed pursuant to the procedures set forth below, or if the game starts with the roof in the closed position, the roof must thereafter remain in the closed position for the duration of the game.
1) In the week prior to a game and on game day, to preserve and protect the field, the League’s tarp rule will be in effect, if the roof is open.
2) No later than one and one-half hours prior to kickoff, the home club is required to notify the Referee or the highest-ranking League official working at the game whether the roof shall be open or closed. The opening or closing of the roof as designated by the home club should be completed no later than the time that the teams take the field for pre-game warm-ups. All overhead lighting must be on prior to team warm-ups and must remain on for the duration of the game.
3) If, subsequent to the home club’s decision to have the roof in the open position for the game, a hazardous condition (lightning, severe winds, etc.) develops or is anticipated that threatens the welfare of participants and/or spectators, as determined by the Referee after receiving input from the Stadium Manager and the highest-ranking League official working at the game, the roof shall be closed immediately. If it begins to rain at any time after the club’s decision to have the roof in the open position for the game, the roof shall be closed immediately, by signal of the Referee to the Stadium Manager.
4) If a game starts with the roof open, it shall be closed at any time due to the development or anticipation of a hazardous condition that threatens the welfare of participants and/or spectators. The game Referee, in consultation with the highest-ranking League official working at the game, after receiving input from the Stadium Manager, will decide if the roof should be closed. If the roof is closed pursuant to the above, it must remain closed for the duration of the game. Play may continue while the roof is being closed, subject to the Referee suspending play pursuant to the procedures for emergency situations.
5) If a game starts with the roof open, it shall be closed at any time up to the last five minutes of the fourth period if it begins to rain. The decision to close the roof will be made by the Referee, who will signal to the Stadium Manager or otherwise communicate to him or her to begin closing the roof. Play will continue while the roof is closing.
6) If the fourth period ends with the roof in the open position, no change will be made prior to or during an overtime period, unless the roof is closed pursuant to the procedures for hazardous conditions as set forth in No. 4 above.
Image credit: Eisenman Architects. Video credit: kevinmidtownindy