In rugby league, each team has 13 players on the field at one time.
The 13-player format is one of the clearest differences between rugby league and rugby union, which traditionally fields 15 players per side. Rugby league teams generally use six forwards and seven backs in their starting structure, although substitutions and tactical changes can alter individual roles during a match.
The modern number developed after the Northern Union split from the Rugby Football Union in 1895. Early rugby football retained larger teams, but rugby league gradually adopted a faster, more open style and reduced the number of players on the pitch. This created more space for running and passing while preserving the physical contest around the ball.
A match-day squad is larger than 13 because teams can name replacements. The exact interchange rules have changed across competitions and eras, so the number of players available on the bench should not be confused with the number playing at once.