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.
Conversion (gridiron football) still used in American football rule books), and thus early scoring rubrics for the game gave more points to the subsequent kick than the actual advancement of the ball over the goal line. The related term "conversion" is still used in both rugby union and rugby league to refer to extra points scored by kicking the ball through the posts after a try has been scored. By the start of the 20th century, touchdowns had become more important and the roles of touchdown and kick were reversed. By this time the point value for the after-touchdown kick had reduced to