The Bill of Rights c.1791

The general rule is that no sign exists until after someone does what the sign instructs not to do (thus my favorite sign is "Do not lick the C-4"). You should consider the Bill of Rights to the American Constitution much like a sign. The reason why those 10 items were enumerated? Because they happened.

I bring this up because one of the most frequent mistakes I see by fantasy authors is applying modern freedoms (and specifically American freedoms) on their fantasy medieval settings. The guard comes and arrests the main character and the main character insists he cannot be arrested unless the guard tells them what he's being arrested for. Oh no, my friends, they absolutely could come and arrest you and not tell you what you were being arrested for. That's why we have an amendment that says you can't do that. Because you could do that. But now you can't.

I think the one that gets me the most is when a main character or a friend screams, "We have a right to [x]!" Son, you don't have a right to shit. You only get the rights the king provides to you and those can and will be changed when the king feels like it because he is appointed by god and/or is god and thus his will is not only a matter of rule but a matter of mandate from heaven, so you should really stop complaining that you can only hunt squirrels now.

Such mistakes are most frequently made by American writers. We're so accustomed to our freedoms being the "right" freedoms that it can be a shock when you find out that modern countries don't necessarily share such rights. (And I'm not talking about communist China, I'm talking about the United Kingdom not having the same provisions of free speech as the US. The right to free speech that we enjoy isn't enjoyed by every G-8 country in the West.)

So read over the bill of rights. Hell, read over all 27 amendments. You may not have to worry about limiting your president to two terms or prohibition, but read them for the signs they are. Until those signs were written, people did them. Soldiers lived in your home whether you wanted them to or not. Your punishment was cruel and unusual (or at least cruel, given its frequency I would assume it became usual). You don't have a right not to incriminate yourself or worship what religion you wish or assembly or a free press.

You only have the right to the law that is dictated by a single man and can be changed just as quickly (unless you've created some kind of parliamentary legal body in which case it comes from a collection of men and can be even harder to change).

Oh, and do not lick the C-4.