Every rally scores a point, whoever served. The side that wins the rally serves next.
Group stage
One game to 21. You need a two-point lead, so 21–20 plays on. At 24–24 the next point wins, so no group game goes past 25.
Knockouts
Best of three games, each to 21 with a two-point lead
Open draw: games are capped at 30, so 29–29 is sudden death
Intermediate draw: games are capped at 25, so 24–24 is sudden death
There is a short interval when the leader reaches 11
In the third game, change ends when the leader reaches 11
If you're unsure about a score, ask the referee before the next serve. The score on the referee's phone is the score of record.