I just played a game where an opponent won a challenge with a maester (with no chains on it), moved a chain to the character after the challenge was won, and then said he could activate the "kneel attached character" or "after character kneels" effect of the chain.

How is there any way this is possible? The character is knelt when the challenge is initiated which is at least 3 action windows before the challenge resolves and the maester gets the chain? I don't think that is legal. Can anyone chime in on this issue?

You're correct.

The attachement has to be "in play" to recognize his character kneeling. It also has to trigger immediately after.

What happened here (as you identified) was

-Declare a Challenge
-Kneel Attackers
(Chance for chain response on those participants kneeling)
Player Action Window
-Declare stealth
-Declare defenders
(Chance for chain response on those participants kneeling)
Player Action Window
-Challenge Resolution
-Resolve Claim
-Award for unopposed
-Claim Renown
(Maester's Path triggers here)



For it to work as your opponent claims, it would have to be "If attached character is kneeling, then X"

Let's be clear about some of the larger issues here.

- First, note that any of the "kneel attached character to" effects from the chains are not going to work when the character is already knelt. The "non-Response" kneels are part of the cost, so if you do not pay the cost by kneeling the character, you can't have the effect.

Look at that one this way: Let's say we have both Lead Link and Gold Link on the same character. Both effects require you to kneel the character for its effect. So, if you kneel the character to pay for Lead Link, does that count as paying the cost for Gold Link, too? No? Because they are separate effects and so the cost must be paid separately for each one? Well, the "paying the cost for Lead counts for paying the cost for Gold, too" is the kind of reasoning your opponent was trying to claim applied when putting such an attachment on a character that is already knelt.

- Second, all Response opportunities are open - and stay open - through the action window in which it was created. So, say you win a challenge and use an effect like "Response: after you win a challenge, put a character into play from your hand" to put a character into play. That character you just put into play has an ability that says something like "Response: after you win a challenge, choose and kneel a character controller by the losing opponent." You can use that Response on the character that just entered play because the "after you win a challenge" Response opportunity is still open. Note that all Response opportunities go away at the end of the window. That's why you cannot kneel the Maester in during your Intrigue challenge, then Respond to it kneeling later during your Power challenge.

- Third, what I just explained above does not count (or almost never counts) for bringing a chain attachment off of the Agenda and onto the Maester. In order to use one of the "Response: after attached character kneels..." effect immediately after being brought into play from the Agenda, there would have to be both an "after you win a challenge" Response opportunity and an "after this character is knelt" Response opportunity. This very rarely happens. You would essentially need to kneel the Maester as part of resolving the challenge (NOT as part of declaring attackers or defenders in that challenge) in order to have a valid "after this character kneels" Response opportunity to coincide with the "after you win a challenge" Response opportunity that let you put the chain attachment into play in the first place.