The only Seven Up I remember was played on rainy days in our classrooms. First, seven kids were selected.The rest of the class put their heads down on their desks with one thumb stuck up (like the “ok” sign). The seven selected students quietly went around the classroom– each one turned down one thumb. When the rest of the class raised their heads, the ones with thumbs turned down had to guess who did it. If you guessed the right kid, you got to be one of the Seven Up.