Badminton in : In, out and the rally · 408

A contest is a compact, high-tempo test of power, control and endurance. Matches are decided over the best of three games to 21 points, with a two-point margin required and a hard cap at 30. Play is continuous but for two short intervals, and the shuttle's rapid deceleration means every point can pivot from an all-out smash to a whisper-quiet net exchange and back again.

Since 2006, every rally scores a point regardless of who served, replacing the old service-only system. A game is played to 21 points; the winner must lead by at least two, so a game can extend past 21 in a deuce. If the score reaches 29-29, the next point wins at 30 — the absolute cap. A side that wins a rally serves next. Winning two games takes the match, and there is no need to play a third game if the first two are won.

The serve must be delivered underhand and, since 2018, struck below a fixed height of 1.15 metres from the court, with the racket shaft pointing downward. Both feet stay stationary and in contact with the floor. The shuttle is hit diagonally into the opponent's service court. The server's score determines the court used: from the right (even) court when the score is even, from the left (odd) court when it is odd. A wrong service court or an illegal action is a service fault.