Mogul skiers race down a 27-degree slope over large uniform bumps called moguls.

The length of the run is between 230 and 270 metres with bumps up to 1.2m high.

Mogul scoring is a combination of judging jumps and bumps and speed.

In a good run, shoulders remain parallel to the finish line, turns should be quick and short, and skis should not leave the snow surface, except at pre-determined jumps.

To perform aerial manoeuvres, skiers hit two large jumps, placed one-third and two-thirds of the way down the run.

The moguls competition consists of a run down a bump-laden course with two jumps.

The Olympic format is a one-run elimination round followed by a one-run final.

The skier with the highest score in the final round wins.

In the aerial competition, athletes perform various combinations of flips and twists off snow-packed jumps as high as 4m (13 feet), with take-off angles as steep as 70 degrees.

Competitors are scored on air, form and the landing.

The Olympic aerial format consists of a two-jump elimination followed by a two-jump final.

The highest total score from the final is the winner.