Rugby is returning to the Olympics for the first time in 92 years, bringing the ruck, the maul and the hooker back into the lexicon of the Summer Games.
The format has changed, considerably, since the United States won the last rugby union Olympic gold medal in 1924, with the abbreviated seven-player version favored for Rio over the traditional 15-a-side game, and Fiji favored for a breakthrough triumph. The aim remains the same: score more tries — grounding the ball in the opponent's in-goal area — and you're a good chance of winning.
It's fast and physical, with more emphasis on speed and passing the ball (always backward) than heavy contact, and it is typically played in two seven-minute halves.