Hey, I was wondering…

If two players own the same king then why doesn't the "if X the only king…"

i mean, he is indeed the only king.

If two players own king stannis then… the kings in play are… well, stannis.

thus, stannis is the only king in play.

The effect is looking for cards with the king trait, regardless of title. So you control a king, and your opponent controls a king. Thus, Stannis is not the only king in play -- there is another king (who happens to have the title Stannis, but that does not matter).

Another reason this is definitely the case is that the card refers to itself (see self-referential cards), and so the line "Stannis Baratheon is the only king in play" cannot refer to (or include) any other copies of Stannis.

I'm curious, assuming all instances of Stannis (or any other King character) are unique, how there could be two of him in play?

One copy controlled by each player.

ziggy2000 said:

So while a single player cannot play, put into play, or take control of a second copy of a unique card that they own or control in play (or is in their dead pile), a second player can play, put into play, or take control of a unique card that an opponent already has in play (assuming they do not already have one of their own).

This is a little different from other games, where "unique" truly means "unique to the game." However, in this game, it means "unique to the player".