Hi,
I would love to see a shadows mechanic that utilizes the fact that cards are played but unknown to the opponent to an even larger extent, something like installed corp cards in Netrunner. What do you think about this:
When you play a shadows card, you don't pay gold for it. You can then 'scheme' the shadows card by playing gold tokens on those cards, basically like advancing in netrunner (maybe this can only be done in the marshalling phase or some other restriction to slow the buildup of tokens on the shadows cards).
When a shadows card is to be brought out of shadows, you can only bring those out that has enough scheming/gold tokens on them.
During an intrigue (and maybe also/instead on a mil/pow) challenge, the opponent who attacks can choose to target specific shadows cards instead of normal claim. The shadows cards can then be dealt with before they become a real threat, OR they can be traps that initiates upon being targeted with 'shadows-claim' leading to all kinds of mind games.
I think it wouldn't change the game too much and still be a very nice ways to add more bluffing and mind-games to AGoT.