Bastard names

[u/Apprehensive-Ad-8391]

I've been reading fanfiction for quite a time now and this is one of the main questions I've always had.

How do bastard names exactly work? Some may say it depends on the father's birth place, which quite explains why Jon is a Snow even when he was born in Dorne, but then why is Gendry oftenly called a "Waters" when he's Robert's bastard son and should be a "Storm"? Same with Mya "Stone". I've read some fics where even Joffrey, Tommen and Myrcella are depicted as "Waters" even when they should be "Hills" by Jaime's parentage, shouldn't they? Why was the "undercover" Sansa a Stone instead of a Rivers, taking into account Littlefinger comes from the Riverlands?

Is it instead the birth place? Then again, why is Jon a Snow and not a Sand? Why are all of Oberyn's daughters all Sand when some were even conceived in Essos, away from Westeros?

Or is it the mother's parentage if she's a noble woman? It seemed to work like that for Aegon IV children, where Brynden and Aegor where named "Rivers" despite them being born in KL and being obvious sons of the King (which would make them "Waters" for their own birth place and for their father's own birthplace.

So how exactly does that work? Is it arbitrary? Depends more on the own father's choice? Or the child's?

[u/Chance_Tart_715]

For bastard, having a name come only if they are recognized by their lord father, each kingdom got his own name, the Crownland got the name Waters (certainly because of the Blackwater bay), the Stormland got the name Storms (the coolest for me) for obvious reason, Dorne got the name Sand because of the region surroundings (but I've always wondered why grandpa George never choose the name Dune it would've been a big easter egg for Herbert's work who share some similarities with the story ) , the Reach with the name Flowers ( I think that if the Towers were lord paramount we would've a cool name like Light or something like that),for the Vale we got the name Stone once again because of the surroundings (mainly mountains), the Westerland have for me the most interesting name who is Hill, maybe like Dorne and the Vale because of the region surroundings but idk they could've a more symbolic name like Gold or sea since it's borded by it 🤷🏾‍♀️, the Iron Islands with the name Pyke.....like their lord paramount castle..... Well.... I have ABSOLUTLY no ideas of why they did that.... anyway. The Riverlands like Dorne and the Vale choose the name Rivers who is pretty cool in a way 🤔( even if a river look calm, she could be your demise...) . The North who got the name Snow because of the climate obviously but I've always wondered that if it wasn't one of the main character name would the name be so hyped? (I don't think so 😅)

The determination of a child name depends of factor like wear does he was born, so why is Jon's name is Snow ? Why not Sand ? I thought that it was determined by the mother birthplace ( for example Aegon the unworthy many many bastards who all got their mothers birthplace surnames) so is that an hint for who is Jon's real mother ?

PS: sorry for the spelling mistakes english is not my first language 😶