One time in second grade we were playing capture the flag in the gym and the only thing I did was walk calmly past the other team and grab the flag. Twice. Both times it took me walking back across the gym and poking the teacher for him to realize I had won. I was that socially invisible.
I used to win tag-in dodgeball in middle school gym classes by standing perfectly still about 2/3 of the way back from the center line. People only aim for moving targets, and everyone knew I had terrible aim, so nobody worried about taking me out until I was literally the last person standing. Then I’d catch all the balls or deflect them with a ball so they landed on our side and tag in the best player.
I won dodgeball for my team at least 3 times that way. I always got chosen last.