A regulation ice hockey game is 60 minutes long. The game is divided into three periods, each of which lasts 20 minutes.
The first, second and third period all have intervals in between them. The average interval lasts for 5 to 20 minutes, depending on the level of play. If the game goes into overtime, it can last longer than usual. When the game is tied at the end of the regulation play, a sudden death period takes place. During sudden death, the first team to score a goal wins. For the National Hockey League, the overtime period lasts five minutes during regular games. During playoff games, the overtime period lasts for 20 minutes or until a goal is scored.
Field hockey varies in length and there are two periods with an intermission in between. Each period lasts for 35 minutes and the interval in between is 5 minutes long. If the game ends in a tie, two 10-minute periods take place to determine the winner. The team with the highest score at the end of the overtime periods wins the game. On occasion, sudden-death overtime is held in field hockey. This also requires two 10-minute periods, but the first team to score is the winner.