A tripping (or obstruction tripping) penalty in ice hockey is called by the referee when a player trips an opposing player with their stick, or uses their skate against the other players skate, causing them to lose balance or fall and obstruct them from making their desired play ("slew footing").
A tripping call usually results in a two-minute minor penalty on the player that caused the infraction. However, if the player is called for slew footing, he receives a match penalty. If the player was tripped on a breakaway (with no opponents to pass other than the goaltender), a tripping call may instead result in a penalty shot for the tripped player.
"Rule 91Tripping". July 13, 2017. Archived from the original on July 13, 2017.