Rugby union – commonly referred to as just rugby, or union, and in New Zealand occasionally as football or footy – is a code of football. Rugby union is a contact sport played by teams with fifteen players. The name is derived from the name of the game's original governing body, the Rugby Football Union, with the suffix union used to differentiate it from other codes of rugby football. The game developed from the variant of football at played Rugby school in England. The crucial differences from association football are that in rugby the ball is a prolate spheroid instead of a sphere, and that the players are allowed to pick the ball up and run with it. The players are also allowed to throw the ball from player to player, but are not allowed to throw it forward – the ball must only be passed sideways or backward.
The game has established itself as a major global sport, and is especially popular in New Zealand, Fiji, Tonga, Samoa, Wales, England, Ireland, Scotland, France, Australia, Argentina and South Africa. Rugby is also gaining popularity in Italy, which was accepted into the Six Nations Championship in 2000, and Japan. Rugby is the most popular team sport in Georgia and is popular in Romania, Namibia, the United States of America and Canada.