The aim of taekwondo is to land as many kicks and blows on your opponent as possible.
Points are awarded for kicks and punches in taekwondo
A bout begins when the referee shouts "shi-jak", with the competitors wearing body, head and shin protectors, mouthguards and a groin guard.
There are three rounds of three minutes each - three of two minutes for women - and the action takes place inside an eight-metre-square zone on a mat.
Victory can be achieved by knockout, by scoring the most points, or by default if the opponent earns eight penalty points or is disqualified.
One point is scored for each strike on the body and two are given if contact is made to the face. Competitors get an additional point for a knockdown.
One referee and three judges oversee the bout and points are awarded only when two or more judges register the hit.
+80kg, -80kg, -68kg, -58kg
+67kg, -67kg, -57kg, -49kg
Kicks to the head and body must be landed with parts of the foot below the ankle, while blows to the body must be with the front of the index and middle finger knuckles of a correctly clenched fist.
Penalties play a major part in any bout. They are awarded for offences such as grabbing, holding, feigning injury, pushing and turning one's back on an opponent.
The most serious offence is the gam-jeom, and leads to one point being deducted.
This is awarded if a competitor throws another, deliberately steps over the boundary line, pulls an opponent to the ground by grappling with their foot in the air or attacks the opponent's face using the hands.
When an opponent is knocked to the ground the referee begins a 10-second count. A knockout occurs if any part of a contestant's body touches the floor, apart from the foot.
DID YOU KNOW?
Taekwondo is a number of ancient martial arts unified into one sport - it translates as "the ways of hands and feet"
There is a mandatory eight count before the referee decides whether the bout should continue.
If a contest ends in a tie on points, then the competitor with the most points before penalties were deducted is the winner.
If it is still tied, the referee awards the contest to the fighter he believes to have showed the most willing.
The only exception occurs in the final, when a tied bout will go to an extra, sudden-death round where the first score wins. If no result is achieved the final decision once again lies with the referee.
The Olympic competition takes the form of an elimination tournament to decide the gold and silver medals.
Two groups are then drawn up of all the competitors who have lost to either of the finalists - except the semi-finalists - and another knockout process produces two pool winners.
They then face the beaten semi-finalist from the other side of the draw, and the winners of the two bouts compete for bronze.