Soccer, also known as Football, is a team sport of human origin. The game was considered to be one of the most popular games on Earth, and spread to other worlds as humanity joined the interstellar community.
Soccer is played between two teams of 11 players each, on a rectangular grass field with a goal on each end. The object of the game is to maneuver the ball into the opposing team's goal, while preventing the opposing team from doing the same. With the exception of the goalkeepers, players are not allowed to use their hands or arms to maneuver the ball.
As a 13 year old, Worf led one of the local youth soccer teams on Gault. While playing against another team, there was an accident in which Worf and another boy named Mikel had a collision, which led to fatal head injuries for Mikel. (DS9episode: "Let He Who Is Without Sin...")