Making the case for Story Games III: Why would you need a rules to make a story together? Why not just talk it through?
I've been talking about the attraction of creating your own stories, and the incentives offered by doing it with other people. (It's worth reading these first to get something out of this post.) At first blush, it might seem like doing things in a freewheeling manner is better than worrying about a bunch of rules. Surely, you just get your creative juices flowing, and run with it? One massive brainstorm?
If this appeals, all power to you! However, there are a number of reasons why using a system may make this activity both more creative and fun.
The first was touched on above: system can be actively involved in creating story. It accomplishes this by offering well-focused constraints on what can happen in the story. The constraint "if any character commits a sin, the next step in the story is to focus on the repercussions of that sin" dictates the progress of certain parts of the story, but doesn't determine the outcome (the repercussions could be infinite in breadth). It also provides an over-arching focus - people creating the story are aware that in this story sin is a major feature - a theme or premise, if you will - and introducing it will drive and direct the story.
The second reason relates to the social aspect of creating story. You know where I said that it's very likely that other people will shake up a story just where you wouldn't? If this gave you any misgivings, hey, I'm with you. Without a guiding system, this could be a recipe for fruitless bickering, with everyone confident that their creative vision is the best. Ultimately things could end up unresolved or decided through force of personality, either way with the potential to bring about ill feeling.
With a system? The problem can largely disappear. "Allan can decide everything that happens in part one of the story - but everyone else gets one overrule that they can use to change something they feel strongly about". If you stick to the system, there's really no avenue to argue, and given a basic level of trust among everyone, the sticky points get passed by quick to get to some more great story.
The third reason I'll offer is even broader, on the social aspect of doing stuff. When I said it "can enhance any activity" I'm sure you came up with counterexamples; we all can. Some of this will be because some people are bad eggs, and a bad egg can ruin any activity. It's a shame, but there you go. Avoid. But many other people will be perfectly cool, and potentially great partners in a number of activities, but only if you're on the same page to begin with. If you want your story to avoid graphic violence, or to offer a redemptive view of religion, it's best to make sure everyone knows this. You can agree on these rules at the beginning, in which case they become part of the system you are using, albeit one spoken rather than written, or you can use a rule-set that lays out the creative experience it intends to emphasise, making sure that everyone finds this interesting. In many cases, you do both.
These are some of the ways in which rules, as a formal explicit part of a story-creating system, can be hugely useful. There is another, hugely important part of using rules. This is that it can make the process into a game*. This isn't necessarily so, as systems like Oulipo, or the strictures of a writers workshop demonstrate, but is true for almost every such system that is used for leisure. The reason is obvious: games are fun. And the very best systems utilise the fun of playing games to produce story as an outcome.
*I'm not going to get into the semantics of what a game is, but use the maxim of 'you know it when you see it'.