I've always said that any RPG rulebook is <Barbarossa Voice> More like guidelines, anyway </Barbarossa Voice> than anything else. But that still means you need some sort of framework there. In this article, game designer Krister Sundelin gives us a look inside how they put together the rules for Troubleshooters.
From the article:
Rules in roleplaying games are a curious phenomenon. Unlike any other game, rules are more like guidelines because of the cooperative nature of roleplaying. Sometimes, the game is best when you don’t even use the rules. In one branch, rulings by the GM is more important than rules themselves. At times I feel that because of the guidelines, rules are haphazardly slapped on to a game setting with no regard to whether they are the right rules. There are also times when I feel that game designers make rules to be different, not to be the right rules.
In the early 2000s, indie game designers came up with the concept of “system matters”. Like every good idea, it sometimes went too far: at times it was innovation for innovation’s sake, not because games needed it, and the games were often one-shots, like a scenario with attached rules. But the general principle is sound.