Quick clarification:

When using Rickon to copy Summoning Season's search effect:

Through the discussion here: http://www.agotcards.org/card/v/4030 we have decided that "Choose an opponent" is not a cost, but a sub-effect of Summoning season. So now it has two sub effects. 1. Choose an Opponent. 2. Search your decks. Those two combine to make up the EFFECT of the card.

So is the intent of the game's copy mechanic to copy the overarching effect of the card being copied, or just the sub-effect that actually includes the searching mechanic?

Well, it's a "then" effect, which always makes things a little murkier, but here is what it comes down to: the "copy the effect" mechanic only copies the effect, not the cost. It does not consider the play restrictions. However, you will often be unable to resolve the effect without also copying the targeting requirement of the original effect.

Look at summoning season. "When revealed, choose an opponent. Then, you and that opponent must each search your decks for a character, reveal it, and put it into your hands. Then, shuffle your decks."

If all you copied was the "you and that opponent must search" - ie, the effect of the plot - how do you define "that opponent"? As far as the copied effect is concerned, there is no one designated as the "that opponent" because the initiation of the effect (where "that opponent" was chosen) was not copied. So unless you are allowed to retarget (and choose an opponent), you cannot resolve the copied effect. So the copy mechanic has always been understood as allowing you to choose new targets (as restricted by the original effect), even though the initiation of the effect has not technically been copied.

So you're saying that you may choose a new opponent, or that the opponent is undefined, so you could just search alone?

Alexander West said:

So you may choose a new opponent and resolve the effect. Note that you are not required to choose the same opponent the original effect chose - after all, it might have been you.

Okay. So on a card like "To be a Wolf", if Rickon copies it, he only copies the search part but not the standing part because those are two separate parts of the card's effect?

Standing the character is the cost of To Be a Wolf (it's a weird kind of cost, but it's still a do X to do Y construct, with X the cost and the effect), that's why it isn't copied. You'll still have to choose an opponent to name a card type (I wonder whether you'd have to choose the same).