Comparison of rugby league and rugby union 1 in league. A penalty goal is worth 3 points in union and 2 points in league. Use of a penalty box (or "sin bin") was introduced by rugby league in 1980. Rugby union had been experimenting with the same concept since 1979, although it was not formally sanctioned until 2001. Video referee technology was first used for rugby league in 1996 and for rugby union in 2001. In rugby league the ball may be thrown or knocked out of play deliberately, while in union those are penalty offences. Kicking the ball out of play is legal in both codes.
Comparison of American football and rugby union of the rugby try. Unlike American football, both codes of rugby require the ball to be grounded, whereas in American football it is sufficient for the ball to enter the end zone (in-goal area) when in the possession of a player. In American football a touchdown scores 6 points; in rugby union a try is worth 5 points. Rugby also allows for a penalty try, awarded by the referee when he believes that a try has been prevented by the defending team's misconduct. In comparison, American football allows the referee to declare that a "Palpably unfair act" was committed by