Football rules for beginners: how to follow a game on TV

What is each team trying to do?

Score by carrying or catching the ball in the other team's end zone, or by kicking it through their goalposts. The field is 100 yards between the goal lines, with a 10-yard end zone at each end, and each team has 11 players on the field at a time.

Teams don't alternate play by play. One team keeps the ball — a drive — until it scores, turns it over, or runs out of downs. That's why a single drive can take several minutes of broadcast time.

How do downs work?

1. 1st & 10 — The offense starts with four downs to gain 10 yards from where the drive's first down began.
2. Gain ground — Each play is a run or a pass. The yards gained are subtracted from the distance still needed.
3. Reach the line, reset — Cross the 10-yard mark (the yellow line on TV) and it's a new first down: four more tries for another 10 yards.
4. Fourth down decision — Short of the line after three downs, the offense usually punts the ball away or kicks a field goal. Going for it and failing hands the other team the ball right there.

How does scoring work?

How does the clock work?

A pro game has four 15-minute quarters with a halftime break after the second. The clock stops for incomplete passes, timeouts, scores, penalties and — at certain times — plays that go out of bounds, which is why an hour of game time fills about three hours of broadcast.

Each team has three timeouts per half. In the pro game there is also an automatic stoppage with two minutes left in each half, the two-minute warning. Tied at the end of regulation, the game goes to overtime; the exact overtime format differs between the regular season, the playoffs and college, and the broadcast explains it when it happens.

What is a turnover?

• Interception — a defender catches a pass meant for the offense. Returned for a touchdown, it's a “pick six”.
• Fumble lost — the ball carrier drops the ball and the defense recovers it.
• Turnover on downs — the offense goes for it on fourth down and falls short.
• A turnover is the fastest momentum swing in the game: the other team starts a drive from wherever the play ended.

What do the flags and penalties mean?

A thrown yellow flag means a referee saw a foul. The play usually runs to completion, then the referee announces the penalty and the yards it costs. A red flag thrown by a coach is different: it's a challenge asking the officials to review the play on replay.

How do you read the score box on TV?

• Team scores and the quarter with the game clock, usually along the bottom or top of the screen.
• Down and distance — “2nd & 7” is second down with 7 yards still needed.
• The play clock — seconds left for the offense to start the next play.
• Timeouts left, shown as small bars or dots beside each team.
• On the field itself, the blue line is where the play starts and the yellow line is the first-down marker. Both are graphics added for TV, not painted on the grass.

Do you need to know all this to enjoy a game with friends?

No. Most of what makes a broadcast exciting — a long touchdown, a turnover, a missed kick, a coach throwing the red flag — is obvious on screen even if you can't explain the rule behind it, and the commentators narrate the rest.

It's also why a live-broadcast party game works for mixed rooms. In Final Whistle most cards describe things anyone can see happen on TV, so the newest fan in the room can call a card as fast as the most devoted one — and the group votes on anything close.