If I have a King's Landing in play and another in shadows, can I pay the cost to bring the 2nd one out of shadows and then apply it as a dupe?
Bringing out of shadows to dupe
Shadowman said:
If I have a King's Landing in play and another in shadows, can I pay the cost to bring the 2nd one out of shadows and then apply it as a dupe?
Yes. From Shadow rules:
If another copy of a unique card that you own and control is in play, you still may bring the card out of Shadows by paying its cost. However, the card immediately attaches to its copy as a duplicate.