Designated Sitter

Plenty of people visit amusement parks and end up having to "baby sit" while others in the group ride rides too extreme for younger guests. Sometimes this duty is rotated among the adults, but sometimes this is the sole reason for that person's presence. The idea is to allow certain amusement park visitors to enter the park for free, predicated on their not riding any rides for the duration of the visit.

Like a designated driver, the designated sitter would need to be unambiguously identified. Designated drivers usually get a pin wrist strap that entitles them to free (non-alcoholic) drinks.

Designated Sitters would have to be treated oppositely. They'd have to be denied an identifying mark which would entitle everyone else to gain entrance to rides. Whether that was accomplished through a breakable wristband, hand stamp or whatever really wouldn't matter, as long as it couldn't be shared with someone else. Maybe the Designated Sitter gets to take the kids to floor shows or something...