Got some questions about some wordings that came up in a game today and want some clarification

1) The character "The Knight" out (Joust, Response: After you win an unopposed challenge, stand The Knight. Then discard the top card of each opponent's deck) and also Scouting Vessel (Challenges, Kneel scouting vessel to choose a defending character, for the duration of the challenge, that character does not count it's STR) are out. If I attack with him and use scouting vessel, does that make the challenge unopposed because there's 0 STR on the defenders end or does opposition just mean that someone had to have knelt regardless of STR?

Also with the card Alannys Greyjoy where I can kneel her to cancel an effect triggered by a player, what does "an effect" constitute? Does that mean any event, text on a location/character, or an item used? Or is it just limited to character abilities?

If anyone can clarify this for me, it'd be great.

TheBlackStones said:

1) Unopposed means 0 STR. So Joust + Scouting Vessel means an unopposed challenge, unless the defender has a bonus to his challengel STR or challenge STR is counted differently (the plot The Grand Melee says challenge STR is counted as the number of participating characters, not the sum of their STR)

2) A triggered effect is any piece of text on a card that begin with a boldface phase name or Response or Any Phase. So is using Ambush (it is an Any Phase action) ; but the FAQ says Agenda effects and Ambush cannot be cancelled.

Thanks, much appreciated.