A power play is hockey's temporary manpower advantage after the other team takes a penalty. The penalty kill is the short-handed team's effort to survive that time, clear the puck, and return to even strength without giving up a goal.
A team is on the power play when the opponent has fewer skaters because of a penalty that affects on-ice strength. The advantage is usually 5-on-4, but it can become 5-on-3 if two penalties leave the same team short-handed at the same time.
The short-handed team is on the penalty kill. It can still attack and score, but it is defending with fewer players until the penalty time expires, a goal cancels the right penalty, or the rulebook creates another release condition.
The standard power-play example is a minor penalty. In many hockey codes, if the non-offending team scores while enjoying that one-player advantage, the minor penalty being served by the short-handed team ends and the penalized player can return.
That does not mean every goal wipes out every penalty. If the goal is scored by the short-handed team, the penalty usually continues. If penalties are stacked, officials have to decide which penalty time is affected. If the goal is scored during a delayed penalty before the whistle, the pending minor may be cancelled or handled differently depending on the rulebook and the penalties already on the board.
Major penalties are different because they are meant to punish more serious conduct. A team on a major-penalty power play can usually score without ending the major early. The penalized team remains short-handed until the full penalty time is served, subject to any additional sanctions or game-specific procedures.
Double minors can also confuse viewers. They are often treated like two separate minor penalties served back to back, so a power-play goal may erase one portion while leaving more penalty time to serve. Exact handling depends on the code and the sequence of penalties.
A 5-on-3 happens when two penalties to the same team overlap and both reduce that team's on-ice strength. It is one of the strongest advantages in hockey because the attacking team can spread the penalty killers out and force longer defensive rotations.
Major rulebooks generally protect a minimum number of skaters. If a team is already down to that minimum and takes another penalty, the extra penalty may be recorded and served, but its clock may not start until earlier penalty time allows it. This is why scoreboard penalty time can look strange during long 5-on-3 sequences.
Because not every goal ends a penalty. A power-play goal usually affects a minor penalty that caused the manpower advantage. It does not normally end a major penalty, a misconduct-only penalty, a coincidental penalty that did not reduce strength, or a penalty belonging to the team that scored while short-handed.
Officials manage the sequence, not just the clock. They identify the foul, announce the penalty, place the player or substitute in the penalty area, adjust the on-ice strength, and restart play at the proper face-off location. During stacked penalties, the penalty timekeeper and officials track which penalty is active, which one is waiting, and which player may return after a goal or expiration.
When a delayed penalty is signaled, the attacking team may pull its goalkeeper for an extra skater before the whistle. That is not a power play yet in the penalty-clock sense; it is an extra-attacker advantage during the delay. The actual power play begins only after the penalty is assessed and play restarts short-handed.