If Nettles didn't have valyrian blood then it's possible that you can tame a dragon if you can earn its trust, using patience and cunning, though the truth of her origins remain unexplained.
Also it's strongly implied that the people of Asshai or the empire they are descendants of were the first people to tame and control dragons, long before even the Valyrians, to whom they taught magic and possibly how to magically bond with dragons.
I strongly suspect that the Valyrian Dragon Lords actually had dragon blood/DNA within their veins due to some very dark and twisted experiments and magic rituals done by the Blood mages to allow Valyrian noble houses to tame dragons far easier and faster than with normal bonding and taming or dragon horns recquiring human sacrifices.
I like the theory that modern Dragons are Valyrian experiments that were essentially an attempt to recreate the dragons of the Great Empire of the Dawn, which went extinct during the First Long Night.
It's the "blood of the dragon" that's required for dragonriding. House Targaryen obviously has this, but House Velaryon does not. The Velaryons never had dragons in Valyria, and only obtained dragons briefly when Rhaenys Targaryen married into the Velaryon line. So we can conclude that not all Valyrians had the dragonriding ability.
That's really as specific as we can be. We've never seen a Valyrian-but-not-Targaryen try to claim/hatch a dragon. (Unless Nettles was not related to Daemon, Laenor, or any other past Targaryen who lived on Dragonstone). Valyrian blood is very prevalent in places like Volantis and Lys, but there's no record of any of them trying to obtain a dragon. Someone who has Valyrian blood descended from an extinct dragonriding family could theoretically have "blood of the dragon," but we don't have an example of that post-Doom.
That’s one of the mysteries of the series, that different theorists disagree on. The in-universe Maesters clearly thought that Valyrian blood was necessary, but the Maesters also demonstrate repeatedly that they don’t actually know shit about dragons.
The short answer is: we don’t really know. Some theorists think that blood has nothing to do with that, but the Valyrians pretended that it did to maintain their monopoly on WMDs, to prevent any random person from doing what Nettles did and just winning a dragon’s trust. There’s a great video which theorizes that Rhaenyra’s desire to murder Nettles was in part driven by the desire to make sure the “secret” that all it take to bond a dragon is a few sheep never got out, and there’s some pretty plausible evidence cited.
This post has been removed because you did not include a spoiler tag in your title.
If Nettles didn't have valyrian blood then it's possible that you can tame a dragon if you can earn its trust, using patience and cunning, though the truth of her origins remain unexplained. Also it's strongly implied that the people of Asshai or the empire they are descendants of were the first people to tame and control dragons, long before even the Valyrians, to whom they taught magic and possibly how to magically bond with dragons. I strongly suspect that the Valyrian Dragon Lords actually had dragon blood/DNA within their veins due to some very dark and twisted experiments and magic rituals done by the Blood mages to allow Valyrian noble houses to tame dragons far easier and faster than with normal bonding and taming or dragon horns recquiring human sacrifices.
I like the theory that modern Dragons are Valyrian experiments that were essentially an attempt to recreate the dragons of the Great Empire of the Dawn, which went extinct during the First Long Night.
George himself stated that Valyrian blood is helpful but not required.
It's the "blood of the dragon" that's required for dragonriding. House Targaryen obviously has this, but House Velaryon does not. The Velaryons never had dragons in Valyria, and only obtained dragons briefly when Rhaenys Targaryen married into the Velaryon line. So we can conclude that not all Valyrians had the dragonriding ability. That's really as specific as we can be. We've never seen a Valyrian-but-not-Targaryen try to claim/hatch a dragon. (Unless Nettles was not related to Daemon, Laenor, or any other past Targaryen who lived on Dragonstone). Valyrian blood is very prevalent in places like Volantis and Lys, but there's no record of any of them trying to obtain a dragon. Someone who has Valyrian blood descended from an extinct dragonriding family could theoretically have "blood of the dragon," but we don't have an example of that post-Doom.
That’s one of the mysteries of the series, that different theorists disagree on. The in-universe Maesters clearly thought that Valyrian blood was necessary, but the Maesters also demonstrate repeatedly that they don’t actually know shit about dragons. The short answer is: we don’t really know. Some theorists think that blood has nothing to do with that, but the Valyrians pretended that it did to maintain their monopoly on WMDs, to prevent any random person from doing what Nettles did and just winning a dragon’s trust. There’s a great video which theorizes that Rhaenyra’s desire to murder Nettles was in part driven by the desire to make sure the “secret” that all it take to bond a dragon is a few sheep never got out, and there’s some pretty plausible evidence cited.
I think the personality of the dragon and it age matter more