NFL overtime depends on the season stage.

How overtime is sorted

1. Check whether the game is regular season or postseason.
2. Start with the overtime coin toss and first possession.
3. Track whether each team has had a possession opportunity.
4. If both teams have possessed, the next score can end the game.
5. If the game is postseason, continue overtime periods until there is a winner.

Ties are still possible

Regular-season overtime has a fixed extra period. If the score remains tied after that period, the game ends as a tie. That is why end-of-overtime clock management can matter almost as much as field position.

The clock can cut off the response

The regular-season overtime period lasts 10 minutes. The rule gives both teams an opportunity to possess, but it does not extend that fixed period merely because the second team's first drive is still underway. If the clock expires, the result is based on the score at that moment: a tied score produces a tie, while a team that is behind loses. That makes pace, timeout use, and field position important even before ordinary sudden death begins.

Each team receives two timeouts in a regular-season overtime. Fourth-quarter timing principles otherwise apply, so a team cannot treat the period as an untimed possession contest.

No playoff ties

Postseason overtime continues until a winner is decided. Teams switch ends between overtime periods like between regulation quarters, and the game cannot end tied.

Postseason play keeps going

A postseason overtime period lasts 15 minutes. If the score is tied when a period ends, or the second team's initial possession has not finished, another period begins. The game continues for as many periods as necessary. Timeout accounting also differs from the regular season: each team receives three timeouts during an overtime half rather than two for a single 10-minute period.

How the first two drives compare

A touchdown on the opening offensive possession does not automatically end the game under the current format. The opponent normally receives its own possession and can answer. If the first team scores a field goal, the second can win with a touchdown, tie with a field goal, or lose by failing to score. If the first team scores a touchdown and try, the second team can answer with its own touchdown and choose a try result that ties or wins.

After both teams have had an opportunity, compare the score. If one team leads, it wins. If the score is tied, the next score by either team wins. That later phase is the part accurately described as sudden death.

Defensive scores change everything

• Defensive touchdown: if the kicking team's defense takes the ball away and scores during the receiving team's opening possession, the game ends. Both teams have possessed during the play.
• Opening safety: if the team that kicked off scores a safety on the receiving team's initial possession, the game ends immediately.
• Turnover without a score: an interception or fumble recovery ends the offense's opportunity, but the new offense may still need to score or protect its lead.
• After both opportunities: once both teams have had the ball and the score remains tied, the next score wins.

Three quick overtime reads

• Opening touchdown: the second team still gets the ball and must answer before its possession ends or the regular-season clock expires.
• Opening punt: the second team can win immediately with any score because both teams have then had an opportunity to possess.
• Matching field goals: the game moves to sudden death, so the next field goal, touchdown, or safety ends it.

"The first touchdown always wins"

That used to be an easier shortcut, but it is no longer reliable. The current overtime structure is built around possession opportunity first, then sudden death once both teams have had their chance or an exception ends it.

Source material

• NFL Overtime Rules
• NFL Rulebook