A term for a broadcasting provision in professional football in which a game cannot be shown on television in its regional market unless the game is sold out. If there are still tickets available, the game is not shown on television in the home city. Blackouts are rare in the NFL, and usually a bad sign for a football team's long term chances of success.
The blackout rule was used to try to ensure that games would be sold out at the stadium by forcing locals to go to the game if they wanted to see it rather than being able to sit at home and watch the game on television. Due to the popularity of the NFL, blackouts are relatively rare in today's game, only occurring in cities that have underachieving teams, or where the team is not particularly popular. Many teams have sold out many games in a row, and are not worried about blackouts. In certain occasions, the blackout rule can be waived for a game by the NFL.