With the Broncos-Steelers game going into overtime, the new overtime rules come into effect for the first time this season.
In the past, the first team to score would win, regardless of when that was (first possession, second possession, etc).
However, this time, there are only two ways a team can end the game on the first possession. If the offensive team scores a touchdown or if the defending team returns a turnover for a touchdown or forces a safety, the game is over.
But if the offensive team scores a field goal, the other team will have a chance to get the ball. If they go on to score a touchdown, the game will be over. If they score a field goal, it will go into sudden death.
These new rules went into effect at the start of last postseason and were not applicable during the regular season.