<P> Many of the positions have similar names but in practice are very different . The position known as' flanker' is not in rugby league; however the second row in rugby league are loose like the flankers in rugby union while the lock / loose forward in rugby league is similar to the number 8 in rugby union . In the backs, rugby league centres are split into left and right centre rather than inside and outside centres . </P> <P> The reduction in the importance of the scrum and the removal of the line - out from rugby league, has meant it is a faster free flowing game . Very different skill sets and body types needed for the different positions has become more obvious as union players specialise more . For instance, props and hookers in rugby union tend to be among the physically strongest and heaviest players with high levels of scrummaging and mauling skills, but traditionally with limited speed and ball - handling skills . In rugby league, props are physically big, straight running forwards whose job it is to set the platform and get the go forward while still possessing agility and good ball handling skills . Locks in union tend to be very tall and high jumpers, as this helps at line - outs; while as this is not a necessity for league; the two second rowers and the loose forward / lock are mobile with speed across the park who can off - load on attack and contain and enforce on defence . They are similar to the loose forward trio of flankers and number eight in rugby union . Depending on their speed and ball playing skills, lock forwards in rugby league can generally play as both a forward and as an extra five - eight . </P> <P> Scrum - half is a specialized position in rugby union and similar to the hooker in league: the number 9 initiates most moves by his or her team and must be an excellent passer of the ball in rugby union as with league . In rugby league any player can act from dummy half, however, in the professional modern game it is a specialised job for the hooker to instigate and direct the forward platform . He must also be able to probe with a running and varied kicking game from dummy half while still possessing strong and effective tackling . </P> <P> The similarity between the two games has meant that players can switch between the two codes . League initially recruited big name players from union, like Herbert "Dally" Messenger in 1907, and the RFU responded by banning any player that played rugby league for life . A push into converting union players to rugby league, such as All Blacks John Gallagher, Frano Botica, Matthew Ridge and Va'aiga Tuigamala, occurred during the late 1980s and into the 1990s . When rugby union became professional league players were allowed to play for rugby union teams, leading to a reversal in cross-code switching . Gallagher, Botica and Tuigamala returned to union, while leading league players such as Jason Robinson, Wendell Sailor, Mat Rogers, Lote Tuqiri, Henry Paul and Iestyn Harris, took up rugby union contracts . Sailor, Rogers, Tuqiri, Paul and Harris subsequently switched back to rugby league . Players who achieve play international rugby in both codes are known as dual - code internationals . </P>

What's the difference between rugby league and union