>>2531869No gradual stripping or masturbation for mine - it's gotta be a nopan theme.
Start with two teams of about 5 girls each, all wearing identical long flowing skirts, fully opaque but very lightweight. Each team does activities like stair climbing or tightrope walking or pulling objects out of a bin, while the opposing team watches. After every round, contestants try to guess the color of an opposing contestant's panties, and any panties that are guessed correctly get taken off, while a contestant that makes a correct guess gets a new pair. The contestants that were faster with their own challenges that round get to guess first, while the one who completed hers slowest doesn't get a guess. After each round the skirts get shorter, and eventually the team with no panties left is eliminated.
Between rounds each team can secretly exchange their panties to strategically protect a teammate who might have been seen but not guessed the previous round or to keep the opposition guessing about who they need to watch closest, or just to keep their remaining panties hidden on the safest teammate.
And possibly the replacement panties are skimpier than the originals and therefore harder to identify. But eventually of course the skirts will just be too tiny to hide anything without a teammate to help protect them, and later rounds could add inconveniently placed mirrors on the walls or fans in the floor.