[SPOILERS] 5x04 Episode Discussion (airs 3rd May 2015)

And then forgotten

Let's just accept the fact that "King's Blood" is a very malleable and vague concept that neither the books or show has bothered to set ground rules on which means they are allowed to say whoever they want to has King's blood as far as it suits the plot.

Let's not go down the rabbit hole here because you're simply arguing semantics that have not been expressly established in either medium.

Yeah I can't remember exactly how things went down in ADWD either.  I can't remember if Stannis wanted the wildings but I do remember Jon convincing Stannis to recruit the mountain clans for help.

Stannis was going to take Wildlings with him in the book until Jon bargained for them. Stannis planned on using the wives and children as hostages in order to assure their loyalty. So yes, it was in there.

The problem is that there aren't any. Neither the show nor the books specify what makes king's blood, who you have to be related to and by how much.

If Joffrey can have King's blood without any blood connection to Robert or the Targaryens, or Gendry can have enough king's blood from being Robert's bastard, who usurped the throne, or Prince Doran, who is defacto king of Dorne but only has king's blood because he's an ancestor of a Targaryen, then it makes no sense to say that Jon Snow, half brother to the King in the North and descendant of the Kings of Winter, doesn't have King's blood or "enough' king's blood.

I think the whole thing is a crock, myself. King's blood is only important because people say it is...which gives the magic its power.

There are rules, Martin just isn't interested in telling you them which allows him to use King's blood as a plot device whenever it's convenient for him.

I think the whole blood of kings thing is sketchy too. She thought Mance counted too and wanted his kid for sacrifice which is why they did the baby swap. I mean how is he a king? The Wildlings don't even really acknowledge the same protocols as people south of the wall, so "King Beyond The Wall" is just a title people south gave him, not the Wildlings. It was always a criticism of mine from the books and I'm glad they left that out of the show.

*Edit: Technically the Targaryens were kings/queens by conquest as well, so really the 'king' legitimacy thing is only by title or acknowledgement of the people. I'd say it mattered who sat the Iron throne or who was crowned by the Septons, but that obviously doesn't matter to Melisandre or her weird religion.

Thanks for all those detailed clarifications. I'm always happy to have folks better versed in the books than myself give some background because I always learn so much. My interpretations and memory are often fuzzy when it comes to some of those minute details especially from ADWD which is why I'm starting a re-read because a lot of the changes they've made between show and book are confusing me to no end! Since we're now moving into uncharted territory with the show, I think it's important to be up to speed on ADWD (at least the last third that merged the timeline) events.

You're right about the baby-swap incident now that you've reminded me those details. I was mis-remembering it being Mel's whole plot but there were others involved with that plan. I think the baby swap particularly upset me because at the time I read AFFC originally I had a baby myself and it was hard to bear Gilly's pain at having to nurse another woman's child while her own was in danger. That whole Oldtown journey for Sam and Gilly was a complete blur to me ... I think I skimmed most of it! 

As for the idea that kingsblood could actually be associated with blood of the dragon, that's interesting and since there's a lot of Targ blood in many of the noble houses, I could see that being a viable theory for sure. Someone asked why the Red Priest in Volantis (on the show) was preaching about the dragon and Dany being the coming of the light and I have to wonder if they're tying that in for that reason...blood of the dragon. The waking of the dragons by Dany has always been said to be the reason why magic was returning to the world in both Essos and Westeros. Is it the reason the Others are on the move? 

But the point is that we've never actually seen King's blood having a real value. We don't know if the leeches had any effect on the three kings deaths (GRRM cleverly made it so that we can understand whatever we like from it), nor do we know if the sacrifices of Mance's baby, Joffrey, Tommen, or any Targaryen would have any power. We don't know it, that's why there are no rules. There might not even be an effect; it is still an open question.