New RPGs, and numerous advice columns - like this one - suggest that when in doubt you make the ruling or decision that is in the best interest for the story. To some people this statement has an intuitive meaning. For others it is less so. I never thought about that until I saw a rant the Angry GM had on twitter (fair warning, he can be abrasive at times and I don't agree with everything he says but he regularly has good gaming advice.) recently where he said it was basically a meaningless statement. It got me to thinking, and I find that on this issue I actually stand opposed to Angry's rants. Today I want to explain why, and how "for the good of the story" is anything but meaningless drivel.
The Crux of the Rant
Angry's rant focused on this core fact: the story is just whatever happens in a game, therefore everything that happens is part of the story and thus for the good of the story. This means that any decision, regardless of outcome, is for the story making it meaningless advice.
It is not a position without merit, but it also isn't a complete picture. For one thing, while it is true that whatever happens is part of the story that doesn't mean it is in the best interest of the story. There are plenty of shitty stories out there, just like there are plenty of shitty games out there. Very few people set out to run a shitty game or story, and so advice that helps push things towards a better story/game is thus with merit. But how does that work?
The Purpose of a Story
The purpose of a story is to entertain, often while teaching some lesson (a moral) or discussing some underlying trend (a theme.) In its core function this makes a story the same as a game, its purpose is to entertain. Stories and games follow different rules and have different needs though. Stories need characters, plot, and tension to be entertaining. Games need rules, challenge, and some way of progressing through it.
These two things then get fused together in an RPG where you have characters, plot, tension, rules, challenge, and meansof progression. This is why even at their most dungeon crawliest of crunch fests RPGs are "Story Games." However, this doesn't mean that the story, or game, partof a particular game are good or bad, and every game is going to lie somewhere different on the scale of Pure Story to Pure Game.
What Makes a Good Story
Boiled down to its core points of Characters, Plot, and Tension we can look at those points and define what makes them good. To keep going in simple terms,
Characters are good when they are interesting. I'll leave it up to you to decide what makes an interesting character and what doesn't. I know my tastes have changed over the years, and I only need to suggest running a Super Hero game to be reminded how varied the interests of my own playgroup are. Beyond being Interesting, for a story to be good (on the character level) the character also has to be consistent. Any time a character acts in a way that is not consistent with the character our brain notes it, is jarred out of the story's narrative, and we tend to think of it as being less good because things happen for the sake of them happening.
Plot, like characters, have to be interesting. Again, this is to taste. Some people love Romantic Comedies. Other people love slasher flicks. Both use different plots but it doesn't mean they're bad. A plot also has to make sense. How does a plot make sense? By being internally consistent. You can have the most interesting plot in the world, but if it doesn't make sense - if it isn't internally consistent - people aren't going to like it as much.
Finally, we have tension. Tension is caused by conflict, and to be more specific it is caused by meaningful conflict. Any time a character can lose or be harmed whether on a social, physical, spiritual, mental, or other level there is tension. Tension is what pulls you to the edge of your seat in a movie theater, and what makes people sit up a bit straighter or stay up way past their bed time when reading a good book. Tension has to be well managed for a story to be good. Too little and the story or scene is boring. Too much and you will exhaust your audience and they will lose interest because it is literally stressing them out.
"For The Good of the Story"
Put all of this together and we have an argument that makes sense for the good of the story. The reason people should, when all else is equal, take actions that are for the good of the story is because it makes the story, and thus game (since story/game are linked in an RPG) better. I'll let you decide if you want it better for yourself or better for the group (generally I find betterfor the group is best, but I don't expect everyone to agree with me.)
That means that if you're GMing and there is a rules question you don't know how to decide so you go in the way that keeps the plot making sense, or adds/eases the right amount of tension to a scene, then you have made a decision for the good of the story.
On the other hand, making a character run away because you don't want them to die - despite the fact they are established as a "fight to the death" type of character - is not for the good of the story because it breaks the character's consistency.
Obviously both could have numerous situations that makes them go the other way, but those exceptions too are mired in the context of the story.
I agree with Angry that the story is everything that happens in the game. But if story is everything in the game, why would you think making a decision geared towards making that story more successful, more entertaining, would ever be a meaningless piece of fluff?