Offside
The provision as it is printed, and everything on Ruleside that turns on it.
A player in an offside position (A) may be penalised before playing or touching the ball, if, in the opinion of the referee, no other team-mate in an onside position has the opportunity to play the ball.
Worked by IFAB itself 1
One of the positions the Laws answer by name rather than by rule, drawn.
The Laws of the Game are published by The IFAB and quoted here for the purpose of explaining the decisions on this site. Ruleside is not affiliated with The IFAB or FIFA. Every clause of Practical guidelines for match officials that Ruleside cites.