Stark location Winterfell:

Marshalling: Kneel Gates of Winterfell to reveal the top card of your deck. If that card is a House Stark character, put it into play knelt. Otherwise, discard it.

What happens if the card that I reveal is a character but that character is already in play (and standing)?

It's not so great if I have to attach it as a duplicate but then have to kneel my main character!

If it is unique character you already have in play, then you simply attach it as it's duplicate and that is all.

Thanks Bomb - However, is there any reason / rational for just adding the card as a duplicate without kneeling the character

There's nothing in the text which suggests that if the card is a duplicate that I can still put it into play

In this instance we actually played that I could just discard the card as I did not want to kneel the character - the (questionable) rational being that the card was a duplicate and not a character and therefore gets discarded

HastAttack said:

You attempt to put the character into play knelt, it enters play knelt and then immediately attaches as a duplicate to the standing character.

HastAttack said:

Unfortunately the answer is no. There is no written rule stating this. It is understood from the CCG era of the game. The designers of this game tend to make certain assumptions about their player base understanding certain concepts when they create cards. It's rather unfortunate.

A card only becomes a duplicate upon it entering play. It's still a character card and qualifies as a character card while it's out of play. This is why you can use Winterfell Gates in such a manner.