A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 29 December 2013
So I'm trying to figure this out as best as I can using the IvE rules changes PDF, but it's a little confusing. Here's the situation:
My opponent plays Sneak Attack as his first engage, we both pass after that. For his first action he wants to use his Unchecked Fury, so according to the PDF he announces the action (step 1), pays the cost of the spell he's planning to attach (step 2), I then interrupt with Entrenched Position (step 3), which will then negate all the actions effects (step 4).
So a couple questions...when my opponent pays gold in step 2, he has to pay at least as much as the goldcost of the spell he will be equipping, correct? Secondly, if that's the case, as I will never see the spell he is attempting to equip when I negate the actions' effects, how am I supposed to ascertain if my opponent actually paid the correct amount of gold for the spell?
Ben Higgins (rules official), 1 January 2014
...when my opponent pays gold in step 2, he has to pay at least as much as the goldcost of the spell he will be equipping, correct?
Correct.
Secondly, if that's the case, as I will never see the spell he is attempting to equip when I negate the actions' effects, how am I supposed to ascertain if my opponent actually paid the correct amount of gold for the spell?
The Good Faith Rule and the tournament Floor Rules are what covers this aspect of the card interactions. If you feel you are being mislead by your opponent, call a judge. The judge can then verify that there was a legal Spell card in your opponents hand.
A player, 2 January 2014
But wouldn't the spell be discarded, so you could see the gold cost needed? Because of the change in rules caused from Paneki's mask exploit.
Alex Jones (rules official), 3 January 2014
But wouldn't the spell be discarded, so you could see the gold cost needed? Because of the change in rules caused from Paneki's mask exploit.
You may be misunderstanding the change to the rules that "fixed" Paneki's Mask exp.
That change involved clarifying taking actions on cards that are not in play: they are now played like Strategies, entering a Resolution area when the action is announced, and, if they are still in that Resolution area when the action ends, being discarded. Cards that enter play are placed in an Entering Play area before actually entering play, and return to their previous location if the entering play fails. Thus, a Strategy, or other card that's being played for its own action, returns to the Resolution area if it fails to enter play (or stays there all the time if no such attempt is made), and is discarded from the Resolution area after the action; a card which is entering play from hand via an action on another card or in the rulebook is placed into the Entering Play area from hand, and returns to hand if the attempt fails, where it is safe from being discarded, and if the entire Equip effect is prevented, no card is ever placed in the Entering Play area.
When paying the cost of Unchecked Fury, or any other Equip action, you must have at least one suitable attachment in hand, and you must pay at least the cost of one such suitable attachment, to satisfy Good Faith. You do not, however, need to select that attachment until you resolve the effects of the action; if the action's effects are prevented, you never make that selection.