The World Club Series was an annual rugby league football competition played between clubs from the NRL (Australia and New Zealand) and the Super League (England and France). The competition culminated with the World Club Challenge, a single match played between the reigning champions of each league. The World Club Challenge was first contested in 1976 and was expanded to include two invited teams from each league playing a short Series in 2015. The Series was reduced to one invited team from each league in 2017, and suspended (only the usual Challenge was played) in 2018.