The problem with your "Law of Laws" is that not all laws are fair and equal. In the case of a tyrannical and/or despotic government the laws in place are going to be written specifically to protect and enforce the power of the people already in charge.

 

 Do you think real world tyrannical dictators actually follow the laws and regulations of their own nations - their own making, even? 

No, they don't. They set up a few particular excemptions to keep themselves in power, and rule - primarily - through corruption. 

 Quote from ilovepoppunk >>

sounds interesting but after a moment of thought that's just lawful stupid: the faction. Would be more interesting as an NPC faction the players invariably find themselves opposing than a player option.

 This again. 

It's not. Moving on.

Okay hypothetical situation: a king hates halflings and has all halflings declared criminals.  All their wealth and possessions now belong to the Crown, and all halflings are to be rounded up and sent to the salt mines where they'll be worked to death- average survival rate is less than three months, shorter if they're elderly, children, or have health problems.  What would this paladin order do?

Quote from 6thLyranGuard >>

Okay hypothetical situation: a king hates halflings and has all halflings declared criminals.  All their wealth and possessions now belong to the Crown, and all halflings are to be rounded up and sent to the salt mines where they'll be worked to death- average survival rate is less than three months, shorter if they're elderly, children, or have health problems.  What would this paladin order do?

 See - good question. And it seems like you've got me there, right? How can I possibly reply to that. 

But it's depressingly simple: They don't go there unless they have a way to act. 

So you could say there's two answers: Is this in a country or city state where the order is established - or a neighboring ditto?

If such a law was passed in a place where the Grey Guard already operated, they would oppose such laws - and the people trying to pass it - with any and every method available within the law. And if unable to credibly, legally move against the crown, they'd uproot and leave. Continue looking for an angle to move against them from outside the borders - but still, legally.

If it happened in a neighboring country, it would basically be the same, without the uprooting: Find out what laws the crown isn't keeping to, then move.

And then you say: Ahh - but what if, while moving against the crown, the Grey Guard comes across a young halfling mother fleeing the tyranny with her three small children - Effin, and the twins Oda and Clef - what then? The law is clear: They must be arrested and handed over to the authorities. 

But no. Because the crown are lawbreakers (or the GG wouldn't be moving against them), so their laws are secondary to the Law of Laws. So the halfling mother and her kids are escorted to safety elsewhere.

I'm going to claim that tyrants and evil oppressors of all brands are simply incapable of staying within the law. We have no end of RL examples, and I cannot think of a single one that isn't based primarily on corruption - even more, it requires corruption to ever even get started. So I doubt your theoretical example would ever come up - specifically, as I'm the GM, I can guarantee it never does. This isn't for publication or wide distribution. It's for me, and my group.

Actually, that question wasn't a gotcha, I just wanted to know how they'd act.

The big sticking point that people seem to be disagreeing with you on is that you keep saying things like "the crown are lawbreakers" or "tyrants and oppressors are incapable of staying within the law."  The problem here is that in a pseudo-Medieval setting like most D&D worlds, the crown is the law.  The idea that the crown and the commoners are all bound under the same laws is not one that's automatic, even in good-aligned rulers.  The exceptions to the laws that let the king do evil things and get away with it?  Those are still laws.