All you do is drop something on the person below you, and they do something with it. Then that person drops something and it keeps going.
Ex:
Person 1: Drops a kitten.
Person 2: Plays with it. Drops a pencil.
Person 3: Draws with it.
Drops a flashlight
Ex:
Person 1: Drops a kitten.
Person 2: Plays with it. Drops a pencil.
Person 3: Draws with it.
Drops a flashlight