Rugby league football is a full-contact team sport played by two teams of thirteen on a rectangular grass field. Rugby league is one of the two major codes of rugby football, the other being rugby union. Rugby league takes its name from what was initially a breakaway faction of the English Rugby Football Union (RFU) known as the Northern Union in 1895, and was played under the same rules as rugby at first. When similar breakaway factions occurred from RFU-affiliated Rugby Unions in Australia and New Zealand in 1907 and 1908 they formed associations known as Rugby Leagues and introduced modified Northern Union rules. The Northern Union later changed its name to the Rugby Football League. Thus, the game became known as rugby league. Over the following decades the game's rules were gradually changed and now rugby league is a distinctly different sport. The aim of the game is to score points by carrying an oval ball (the correct geometric shape is a prolate spheroid) up the field towards the opposing team's in-goal where the ball is grounded to score a try (worth four points). This is to be done by the attacking team within a "set of six" tackles allowed before the ball must be handed over to the opposition. At the end of a set of six, unless the attacking team is in good field position from where they can attempt to score a try, the team with the ball will usually elect to kick the ball to the adjacent end of the field, thereby forcing the opposing team to run the ball from as far away from their own try line as possible. The opposing team attempts to prevent the attacking team from carrying out this objective by tackling the player with the ball. After scoring a try the scoring team then has the right to attempt to kick a goal (worth a further two points if successful). The kick may be taken from any point on an imaginary line parallel with the touch-line and through the point where the try was scored. The team with the most points at the end of two 40-minute halves wins. Full Article on Wikipedia