Court Build-off.

Twelve teams of three, picked by shuttle toss, got one badminton court and six hours each. No theme announced beforehand — the brief was revealed at the net once every team had claimed a side. Power cables ran along the tramlines, the scoreboard app was built the night before by someone who then had to compete against it, and demos were played like an actual rally: three minutes to serve your idea, two minutes for the crowd to return it. The verdict came from a show of hands at the net, which is a worse voting system than almost any alternative and also the only one anybody enjoyed.