- Don't write a Law when a Guideline will suffice.
- Don't write a Guideline when tweaking Custom will suffice.
- And don't try to change Custom when it isn't broken in the first place.
First off: Royalty trying to write Laws to tie the hands of later Royalty is simply a waste of time, guaranteed to get everybody angry for no good reason. If the next Royals disagree, they can simply change the Law back, and we get into silly tit-for-tat rewritings, using the Law as a political football. This makes everyone involved look bad, weakens everybody's respect for the Law, and hurts the Kingdom for no benefit. (This is trebly true if it's trying to change something that previous Monarchs *have* been doing, because it often comes across, with some justification, as a personal rebuke of how they governed.)
Second, this illustrates one of the key points of the Rules: that the "lower" levels are often more powerful than the "higher" ones. That is, Law can look arbitrary and over-powered: when you try to write something into Law, it leaves no room for maneuver, no wiggle-room for the exceptions (and there will *always* be exceptions), so people argue about it and disrespect it. Whereas writing a Guideline leaves future generations the flexibility they need to deal with the circumstances on the ground. And simply setting a good example -- making clear what you think, why you think it, and *doing* that -- is often most powerful. It doesn't try to *control* future Royalty (which many of them will find frustrating and resist), but simply tries to *influence* them for the better, which is something you really can do. It's notable that the Monarchs who have most influenced the course of the Kingdom have often made relatively few changes to Law, because rewriting Law (unintuitively) tends to make you *less* influential.
I'll be frank -- IMO, this is one of those cases where the Third Rule applies: I'm not sure the current situation is broken. Yes, some Royalty give out Court Baronies rather freely, but I know of few cases where they seem to be genuinely undeserved. But even if you think it *is* broken, trying to change Law is the wrong way to go about it, because it doesn't win the hearts-and-minds battle that is really at the center: it's neither necessary nor sufficient. Instead, you need to *convince* the current Royalty, some Royal Peers and as many of the up-and-coming contenders as possible that things should change, and you need to make clear to them *why* it should change, patiently and persistently. If you can't make a good enough argument to convince them, then you should consider that you might be wrong. And if you *can* convince them, then you've won anyway, and there is no need to go screwing around with Law...