Most readers of this blog, as citizens of England and Wales, the US, Australia and so forth, will be at least somewhat familiar with the common law - that is, law created by judges rather than by statute. (Though it's my experience that most lay people in England are astonished to learn that the great majority of the principles of English law were not produced by parliament but by courts. Maybe in the US, where cases like Roe v. Wade are so much in the public eye, people are more familiar with the way the system works.) The common law is based on a very simple concept - that judges hear cases, apply precedent and their common sense, and come up with a decision. If there is no precedent, their decision itself becomes the precedent for future cases. Bob's your uncle. It's much more complicated than this (don't let's get started on Lord Denning), but that's the basic mechanism.
I sometimes wonder how a game's rules would look if they were created in this way. Ideally, a common law system has more than one judge, so you would need to have a number of different groups involved (or, more practically, perhaps one large group with a rotating DM). You would start off with an empty page, blank except for the word "rules" written at the top. This would be the blank slate on which the "common game rues" would be set down. Everything that came afterwards would arise through quasi-judicial process.
Here's how it might work. An important aspect of the common law is that it is based on adversarial, rather than investigative, discourse. Two barristers put their case to the judge in an attempt to demonstrate firstly that their arguments are logically sound, and secondly that they follow precedent. In our common law game design system, the adversarial aspect is the realm of the players. The DM is the judge.
First of all, you would probably need a system of character generation. The DM would nominate two players to put forward tentative character generation methods (roll 3d6 for a set of stats, distribute x number of points, etc.), listen carefully to their arguments and any supporting evidence or witnesses/independent experts (the other players), and make a decision. Since there is no precedent on which to base this (it is a case of first impression, to use the technical term) the decision comes down entirely to the discretion of the DM. Character generation proceeds. Some other questions may arise (what benefits accrue to high stats, or penalties to low ones?). These can be dealt with as individual "cases", taking the format described above, or they can be decided by the DM as an aside. (A little like obiter dicta, if that doesn't stretch the analogy too far.) Finally, we have something approaching a set of rules and standards for character generation.
It is important at this stage to point out that these rules and standards will not be coherent or universal. For instance, all of the players may have chosen characters with roles like "warrior" or "magician", but none like a "priest". Therefore, there will as yet be no rules for how to make a "priest". When character generation next takes place (a new campaign, or when a character has to be replaced) a player might express the desire to play a "priest", and so the rules and standards for character generation will have to be expanded; again, two players will argue the ins and outs of this before the DM, demonstrating that their proposals are in line with the precedent set out previously.
Character generation is over and the game proceeds. The PCs come across a chasm. One attempts to jump across. How are we to judge success? A new case has come before the judge. Two players put forth proposals, and the case is decided. It may be that there is already a "jump" skill that has been put forward during the character generation process, or an opinion on the matter may have been expressed but left undecided. These issues will have relevance as precedent, and the DM and players will have to obey the principle of stare decisis in deciding the matter. Their decision will be incorporated into the rules, and will itself form precedent for future cases.
Matters become more interesting from now on. What happens next time a character tries to jump across a chasm? It's in the rules, so the case is simple. What if he's trying to jump onto a moving object? The same rules may apply, but it may also be argued that since circumstances are sufficiently different, this new instance constitutes a case of first impression and a different rule must be created. Or, the decision in the initial case in which the rules on the "jump" skill were decided may contain, in the obiter, opinions on how all "skill" usages are to be ruled upon, and this may have an influence.
Yes I do have too much time on my hands; your point being?