This is the freaking Emperor of Niilfgard. You were saying?
... SPOILERS!
Oh, wait, that was the TV show.
Still, I recall that he worn a funny-shaped helmet to hide his identity.
My point is that a magical curse in no way seems to impact the legitimacy of a claim. Curses are a way of life in that world.
I think that would be arguable. For one thing, as far as I played the game, I have heard of no other king or emperor that was cursed (openly).
Henselt downright said (while I accidentally explored his dialogue options on the matter) that he will not acknowledge a Queen that has a curse that turns her into a man-eating monster.
Curses may be one thing (Henselt himself), but curses resulting in transformation into man-eating beasts are a different cattle of fish. Especially when it does not seem to be easily removed.
^True, but I see no reason why that should delegitimize her completely and rule out a succession. After all, the same thing happened before once already and she was not delegitimzed back then....
That's because her father was alive. He is not now.
I recall that claims to the throne were not simple in medieval life, it's politics often involving not only legitimacy but who had a superior force behind him: even if our laws don't match, I don't see how that would be different. For all we know, she has no legal problems getting the throne, but plenty of political ones if she attempted to get it (or she has/will).
In one of the DLCs for the first game, we had another cursed princess/heiress (the curse of the black sun) where it was outright stated that the king refuses to have a cursed heiress.
The thing is though, that according to TW1 it was widely known that she already had to wear a special medaillon to remain normal. So if that did not delegitimize her already....
Actually, no, it was not. Unless I missed that part, the bits about the medallion and whatnot were kept secret, hence her negative reaction when Geralt asked about it in the first game.