Here’s the 411 on how a game starts and ends. This is for traditional games within the 82-game season. This does not count the Stanley Cup Playoffs.
A hockey game is 3 periods of 20 minutes apiece, with a 17 minute intermission in between periods. If the game is tied at the end of regulation (meaning all 3 periods of hockey were played), then the game goes into overtime. As of 2018, overtime is 5 minutes long; if no team scores after overtime is over, the play extends to a shoot out to decide a winner.
After each period, the teams change sides.
When the game starts, 6 players are on the ice: 3 forwards, 2 defensemen, and 1 goalie. The team who scores the most goals wins the game.
Penalties/Power Play (PP)/Penalty Kill (PK)
Penalties are called when a player (or team) has conducted an illegal action that goes against the rules of the NHL. Penalties can be called against a player, or against a bench, depending on the circumstances. Traditionally, most penalties are on the players.
Penalties can be for 2 to 10 minutes, depending on the situation and the severity (fighting is always 5 or more). Penalties can also stack against a player (i.e., a double minor: 4 minutes for high sticking if blood is present; or 2 minutes for roughing plus an additional 2 minutes for unsportsmanlike conduct), resulting in a longer sit in the penalty box. Multiple players can be charged with penalties on the same occasion, or different occasions, while other players are in the penalty box.
Players who meet the requirements for all minor and some major penalties go to the penalty box (i.e. the “sin bin” or “the box”). They sit there for the duration of their penalty minutes, until they have served their time. If they attempt to leave the box, or play a puck while coming out of the penalty box and before both skates touch the ice, it is an automatic minor penalty, and they go back in.
Some exceptions for major penalties result in a player being ejected for game misconduct, or they serve 10 minute misconduct and go to the locker room.
(More details about penalties are in the Hockey FAQ: Penalties section)
If one team has a player who commits a penalty, the opposing team goes on the “power play”. The team whose player committed the offense goes on the “penalty kill”.
While a player is in the box, the player is not replaced on the ice, resulting in a 5-on-4 situation for the duration of the penalty (as long as the other team does not have a player who was sent to the box in the same situation, and did not have a player in there previously). The object for the team on the powerplay is to score before the penalty time is up. The object of the team on the penalty kill is to “kill off” the penalty by defending the goal against the other team, even though they are shorthanded.
A goal scored by a team that’s shorthanded (i.e. they have a player or players in the penalty box), and on the penalty kill, is called a “shorthanded goal”. A goal scored by a team on a power play is a “power play goal”. If Team A has a player in the penalty box for a 2 minute minor, and Team B scores a power play goal, regardless of how long Team A’s player was in the box, the remaining minutes left on the penalty are cancelled out, and Team A’s player can rejoin their team. If Team A’s player was serving a double minor (4 minutes) when a power play goal was made, the double minor is reduced by 2 minutes. The player does not return to the ice after a power play goal if they are serving a major penalty, a misconduct, or a game misconduct.
If both teams have players who committed a minor infraction at the same time, or the penalties against each player are staggered (ex. first Team A has a player in the box for 2 minutes, then Team B’s player goes into the box halfway through Team A’s penalty) both teams lose a player to the box, and they play 4-on-4. If Team A and Team B’s players went into the box at the same time, they both stay there until both penalties are served. If Team A’s player went in first, then 30 seconds later, Team B’s player went in, the teams play 4-on-4 until Team A’s player served his time, and comes out of the box. Once that occurs, it is treated as a 5-on-4 powerplay for the rest of the penalty still being served by Team B’s player.
No one can lose more than 2 players on the ice for penalties: they must have 3 players on the ice at minimum. If more than 2 players are in the same team’s penalty box, players on that team’s active playing roster must be subbed in on the ice to fulfill the minimum 3-person rule. When players come back onto the ice from the penalty box, those subbed in players must immediately head to the bench.
If Team A commits a penalty that took away Team B’s chance to score, Team B may be given a penalty shot by the referee. This is where Team B’s player takes a direct shot at Team A’s goalie, and tries to score. A penalty shot is entirely up to the discretion of the referee.
This is worth mentioning because it happens a lot at the very end of a game. In the event that a team is down a goal or two, they can “pull” the goalie for an extra attacker. A team does this to try and get as many goals as they can, in order to either pull ahead of the other team, or at least get the game into overtime. Pulling the goalie would leave the goal empty, and an opposing player can shoot a puck easily into it… if they can get around the other team’s offense and defense to score.
As expected, pulling the goalie within the last few minutes of a game, and scoring on the man advantage, has a very low success rate.
What happens when the game goes to overtime? Overtime is played with a special 3-on-3 format, meaning each team picks 3 players (usually two forwards and a defensemen), and they play in front of 1 goaltender. The overtime period is “sudden death”, meaning the first team to score is the team that wins. If the overtime period ends with no one scoring, the game goes to a shootout, meaning each team picks their best scorers, and sends them out one at a time to take a shot against the rival goaltender. The shootout lasts at least three rounds, with the possibility of more rounds if the teams are tied in shootout goals (there is one exception. See below). The home team shoots last in each round. The most number of goals within three rounds wins.
If the home team has two goals, and the visiting team has none by the end of the second round, then the home team wins automatically (the visiting team cannot tie the shootout score within three rounds). If the home team has two goals, the visiting team has one, and the visiting team fails to score in the third round, then the home team wins automatically without playing in the third round (the visiting team cannot tie the shootout score within the three rounds given).