[I love the witcher]

What happen in the witcher 2 If we kill the princess Adda?. Which are the consequences?

[dragonbird]

Possible change in some dialogues and outcome. Fairly trivial.

Details below. I recommend you don't read unless you've already completed one run on Roche path.

If you're on Roche path, the discussion with Radovid at Loc Muinne varies depending on whether she's alive (and married to Radovid), or dead. Some other conversations about possible inheritance of the Temerian throne also change throughout the game.

If you rescue Anais, and pass her to Radovid, his plans for Temeria change depending on whether or not Adda's alive. If she is, he declares that he will take care of Anais, and that she will get the throne of Temeria when she's of age. If Adda's dead, he declares that he will marry Anais when she's of age, and the kingdoms will therefore be combined.

If you make other choices throughout the game, Adda being alive or dead has no impact.

[Kindo]

Well, while the direct impact may not be great, it is still a lot less trivial to consider the political consequences of her being married to Radovid or not. Things we don't necessarily get to see in TW2, or even TW3. I wish they had done a bit more, though; both with this and the other plot decisions of TW1 (that didn't even get mentioned in TW2).

[dragonbird]

Kindo said:

Well, while the direct impact may not be great, it is still a lot less trivial to consider the political consequences of her being married to Radovid or not. Things we don't necessarily get to see in TW2, or even TW3. I wish they had done a bit more, though; both with this and the other plot decisions of TW1 (that didn't even get mentioned in TW2). ›››

I was trying not to do too much spoiling, as I don't know if the OP has played through or not
Personally, I think it's trivial as any impact is going to be a few years in the future, and too much can change between now and then.

I agree though about TW1 stuff not having been carried through enough. I hope they do better in TW3.

[I love the witcher]

Don't worry I end the game in both path, but I only want to know if we had any changes killing her or lifting the curse. At the end the king Radovid alway get one Foltet's Daughter. But what happen if insted of Radovid we give Anais to Jhon Natalis?

[dragonbird]

I love the witcher said:

Don't worry I end the game in both path, but I only want to know if we had any changes killing her or lifting the curse. At the end the king Radovid alway get one Foltet's Daughter. But what happen if insted of Radovid we give Anais to Jhon Natalis? ›››

A BIG change in the outcome for Temeria and for Roche's personal future. For you personally, no difference.

You should just play it - go back to a savegame just before the decision point. But if you prefer not to, details below:

Radovid is pissed off with you, and you walk straight into a fight when you leave Dethmold's lair.
Natalis declares that he thinks he can hold things together in Temeria, and that she will be queen, so this is the ONLY option path in which Temeria has any hope of stability and independence in the immediate future (ignoring the minor matter of the impending invasion by Nilfgaard).
Roche continues with his current job, and looks like he's going to be closely involved in protecting Anais in the future.