One of the most exciting moments in hockey is a huge open-ice hit that gets the home crowd off their feet. However, players have to be careful as too many strides can be ruled a charging penalty in the eyes of the referees. The NHL Rulebook states the following about a charging penalty:
"A minor or major penalty shall be imposed on a player who skates, jumps into or charges an opponent in any manner. Charging shall mean the actions of a player who, as a result of distance traveled, shall violently check an opponent in any manner. A “charge” may be the result of a check into the boards, into the goal frame or in open ice. "
Charging also applies to goaltenders, as it is the name of the penalty when a player hits a goalie when he is inside and outside the crease.
"A minor, major or a major and a game misconduct shall be imposed on a player who charges a goalkeeper while the goalkeeper is within his goal crease. A goalkeeper is not “fair game” just because he is outside the goal crease area. The appropriate penalty should be assessed in every case where an opposing player makes unnecessary contact with a goalkeeper. However, incidental contact, at the discretion of the Referee, will be permitted when the goalkeeper is in the act of playing the puck outside his goal crease provided the attacking player has made a reasonable effort to avoid such contact."
One of the more vicious charging penalties in recent memory happened when Paul Byron crushed MacKenzie Weegar against the glass in a game in 2019. Byron was traveling at a high speed when he arrived at Weegar, then left his feet to send Weegar's upper body viciously into the boards.
Charging penalties can be a a very discretionary call. On PK Subban's famous hit on Brad Marchand, you can see that he leaves his feet to make the check but the referees don't rule it as charging.