Here's an idea, what if we had outside forces controlling the story. For example, lets say you have two people playing ball in the park but you want them to go somewhere else. A player could write "Suddenly, it starts to rain" or "Dark storm clouds approach." I call this "playing God" because of the powerful and omniscient control you have over what happens in the world and how this control conveniently changes people's fates. So what does the community think about this mechanic? How could this work in an RP?