Picture the scene: I have two copies of the new Catelyn Stark (" Challenges: Put Catelyn Stark into play from your hand, knelt as a defender during an I or P challenge initiated against you. At the end of the phase, if Catelyn Stark is still in play, return her to your hand. ") in my hand during an I or P challenge initiated against me.

I trigger the effect on the first card, putting her into play. Can I then trigger the same effect on the second copy to put her into play again, this time as a duplicate?

If so, at the end of the phase, assuming both cards are still in play, does one of the Catelyns go back into my hand while the dupe is discarded?

That all seems reasonable, but I just wanted to check.

No, you can only attach a duplicate during your marshaling phase. Catelyn's ability does nothing to override that basic rule.

Greyweather said:

This is untrue. You can only play a duplicate from your hand during Marshaling, but you can use any applicable "put into play" effect to put a second copy of a unique card that you already have in play as a dupe on the first. For example, bringing a second copy of Tyrion out of Shadows will dupe the first. Losing a second copy of Darkstar to an intrigue challenge will dupe the first.

As for your example of Catelyn, yes, the second copy would enter play as a dupe on the first. At the end of the phase, the dupe would be discarded and the "original" would go back to your hand. The dupe would not go back to your hand because when it became a dupe, it stopped being "Catelyn Stark" and became a traitless, titleless, textless dupe - so a second copy of "Catelyn Stark" was not in play. And you could not use the dupe to save Catelyn from being returned to your hand at the end of the phase because you are not allowed to trigger any Response effects at the end of the phase.

ktom said:

Never would have guessed. So Khal Drogo (Core) is the same then?

ktom said:

The bit which caused the confusion was the phrase "put [...] into play from your hand, knelt as a defender ". Putting a card into play as a duplicate isn't quite the same as putting it into play as a knelt defender... or is it?

Thanks for clearing that up.

Greyweather said:

Yup. The abilities are similar enough for that.

Laban Shrewsbury said:

The card leaves your hand as "Catelyn Stark," slated to be knelt as a defender. But when the effect resolves, the second copy becomes a dupe. So the intention when you trigger is to put the card into play as a defender, but the rules for unique kick in during the resolution and morphs the result.