Hockey, and we are talking about ice hockey now, is simply a part of life in Canada. The passion with which it is followed is possibly only comparable to soccer in the UK or an India-Pakistan cricket clash.

As a newcomer to Canada, you might find it strange that a hockey league that is limited to clubs in North America evokes such passion. The sport regularly makes the front pages even in the mainstream national papers, and hockey talk around the water-coolers at work can get quite animated.

The fact is, it is strange only until you start watching the game yourself. It doesn't take long to get drawn into the sport, and before long, you too will be joining the legion of fans for whom every Saturday is Hockey Night in Canada.

The National Hockey League (NHL) is generally recognized as the sport's premier league. While it only features teams from Canada and the United States, the players themselves are drawn from all over the world. There are no limits placed on teams having to pick players from that city alone. This means a team like, say, the Toronto Maple Leafs can feature a dozen nationalities, and zero players from Toronto itself.

If you are new to Canada or to hockey (or both!), sit back and let me explain what the game is all about. Hopefully, it won't be too long before you can join the guys and girls at the water-cooler in discussing last night's exciting game.

Hockey is Canada's official national winter sport, and it has a strong enough following in certain regions of the United States (notably the Northeast, the Northern Midwest, and Alaska) that many Americans consider hockey to be a "major sport" in their country as well. The parts of North America which have the strongest followings of the sport are often called "hockey country".

While most of the countries mentioned above have their own professional ice hockey league, North America's National Hockey League, commonly called the NHL, is considered the world's premier professional ice hockey league and attracts almost all of the world's elite players.

A substitution of an entire unit at once is called a line change. Substitutions are permitted at any time during the course of the game. When players are substituted during play, it is called changing on the fly.

The boards surrounding the ice help keep the puck in play, and play often proceeds for minutes without interruption. When play is stopped, it is restarted with a faceoff, where one player from each side vies to play the puck upon the referee's whistle.

In men's hockey, but not in women's, a player may use his hip or shoulder to hit another player if the player has the puck or is the last to have touched it. This use of the hip and shoulder is called body checking. Not all physical contact is legal -- in particular, most forceful stick-on-body contact is illegal -- as there are many infractions for which a player may be assessed a penalty.

For most penalties, the offending player is sent to the penalty box and his team has to play without him for a short amount of time, giving the other team what is popularly termed a power play. A two-minute minor penalty is often called for lesser infractions such as tripping, elbowing, roughing, boarding, high-sticking, too many players on the ice, illegal equipment, charging (leaping into an opponent), holding, interference, delay of game, hooking, or cross-checking.

More egregious fouls of this type may be penalized by a four-minute double-minor penalty, particularly those which (inadvertently) cause injury to the victimized player. These penalties end either when the time runs out or the other team scores on the power play; in the case of a goal scored during the first two minutes of a double minor, the penalty clock is set down to two minutes upon a score (effectively expiring the first minor). Five-minute major penalties are called for especially violent instances of most minor infractions which result in intentional injury to an opponent, as well as for fighting and spearing. Major penalties are always served in full: they do not terminate on a goal scored by the other team.

Two varieties of penalty do not always require the offending team to play a man down. Ten-minute misconduct penalties are served in full by the penalized player, but his team may immediately substitute another player on the ice unless a minor or major penalty is assessed in conjunction with the misconduct (a two-and-ten or five-and-ten).

In that case, the team designates another player to serve the minor or major; both players go to the penalty box, but only the designee may not be replaced, and he is released upon the expiration of the two or five minutes, at which point the ten-minute misconduct begins.

A player who is tripped by an opponent on a breakaway – when there are no defenders except the goaltender between him and the opponent's goal – is awarded a penalty shot, an attempt to score without opposition from any defenders except the goaltender. A penalty shot is also awarded for a defender other than the goaltender covering the puck in the goal crease.

Offensive tactics include improving a team's position on the ice by advancing the puck out of one's zone towards the opponent's zone, progressively by gaining lines, first your own blue line, then the red line and finally the opponent's blue line.

Offensive tactics are designed ultimately to score a goal by taking a shot. When a player purposefully directs the puck towards the opponent's goal, he or she is said to shoot the puck.

A team that is losing by one or two goals in the last few minutes of play may elect to pull the goalie; that is, removing the goaltender and replacing him or her with an extra attacker on the ice in the hope of gaining enough advantage to score a goal. However, this tactic is extremely risky, and as often as not leads to the winning team scoring a goal in the empty net.

If a game is tied, there is a single five-minute sudden death overtime period, with each team only allowed five players (including goalie) rather than six. If it is still tied after overtime, there is a penalty shootout. This consists of five (or three) players from each team taking penalty shots. After these six (or ten) total shots, the team with the most goals is awarded the victory.

If the score is still tied, the shootout then proceeds to a sudden death (actually sudden victory) format. Regardless of the number of goals scored during the shootout by either team, the final score recorded will give the winning team one more goal than the score at the end of regulation time.