Rugby union, widely known simply as rugby, is a contact team sport that originated in England in the first half of the 19th century. One of the two codes of rugby football, it is based on running with the ball in hand. In its most common form, a game is played between two teams of 15 players using an oval-shaped ball on a rectangular field with H-shaped goalposts at either end. Rugby union is a popular sport around the world, played by male and female players of all ages. In 2014, there were more than 6 million people playing worldwide, of whom 2.36 million were registered players. World Rugby, previously called the International Rugby Football Board (IRFB) and the International Rugby Board (IRB), has been the governing body for rugby union since 1886, and currently has 101 countries as full members and 18 associate members. In 1845, the first football laws were written by pupils at Rugby School; other significant events in the early development of rugby include the decision by Blackheath F.C. to leave the Football Association in 1863 and the split between rugby union and rugby league in 1895. Historically an amateur sport, in 1995 restrictions on payments to players were removed, making the game openly professional at the highest level for the first time. Rugby union spread from the Home Nations of Great Britain and Ireland and was embraced by many of the countries associated with the British Empire. Early exponents of the sport included Australia, New Zealand, South Africa and France. Countries that have adopted rugby union as their de facto national sport include Fiji, Georgia, Madagascar, New Zealand, Samoa, and Tonga. International matches have taken place since 1871 when the first game was played between Scotland and England at Raeburn Place in Edinburgh. The Rugby World Cup, first held in 1987, is contested every four years. The Six Nations Championship in Europe and The Rugby Championship in the Southern Hemisphere are other major international competitions that are held annually. National club and provincial competitions include the Premiership in England, the Top 14 in France, the Mitre 10 Cup in New Zealand, the National Rugby Championship in Australia, and the Currie Cup in South Africa. Other transnational club competitions include the European Rugby Champions Cup, the Pro14 in Europe and South Africa, and Super Rugby in the Southern Hemisphere and Japan.