Minor penalty

A penalty in ice hockey is a punishment for an infringement of the rules. Most penalties are enforced by detaining the offending player within a penalty box for a set number of minutes, during which the player may not participate in play. Penalties are called and enforced by the referee, or in some cases the linesmen. The offending team usually may not replace the player on the ice, leaving them short handed as opposed to full strength. The opposing team is said to be on a power play, having one player more on the ice than the short-handed team. The short handed team is said to be "penalty killing" until the penalty expires and the penalized player returns to play. While standards vary somewhat between leagues, most leagues recognize several common degrees of penalty, as well as common infractions.

The statistic used to track penalties was traditionally called "Penalty Infraction Minutes" (PIM), although the alternate term "penalty minutes" has become common in recent years. It represents the total assessed length of penalties each player or team has accrued.

The first codified rules of hockey, known as the Halifax Rules, were brought to Montreal by James Creighton, who organized the first indoor hockey game in 1875. Two years later, the Montreal Gazette documented the first set of "Montreal Rules", which noted that "charging from behind, tripping, collaring, kicking or shinning the ball shall not be allowed". The only penalty outlined by these rules was that play would be stopped, and a "bully" (faceoff) would take place. Revised rules in 1886 mandated that any player in violation of these rules would be given two warnings, but on a third offence would be removed from the game.

It was not until 1904 that players were ruled off the ice for infractions. At that time, a referee could assess a two-, three- or five-minute penalty, depending on the severity of the foul. By 1914, all penalties were five minutes in length, reduced to three minutes two years later, and the offending player was given an additional fine. When the National Hockey League (NHL) was founded in 1917, it mandated that a team could not substitute for any player who was assessed a penalty, thus requiring them to play shorthanded for the duration. The penalty was shortened to two minutes for the 1921–22 season, while five- and ten-minute penalties were added two years later.

...
Wikipedia