A cup is a single-elimination bracket of 8, 16, or 32 players. 64/128 sizes are not live until 32-player cups are healthy in ops.
Buy-ins lock at join. If the field is not full at start, the cup is annulled and everyone is refunded. There are no underfill byes.
Child matches use code CUP-…, have zero 1v1 stake, and stay out of the open lobby, 1v1 stats, and referral first-match bonuses.