A penalty in ice hockey is a punishment for inappropriate behavior. Most penalties are enforced by detaining the offending player within a penalty box for a set number of minutes, during which, the player can not participate in play. 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.