Is Painful Quandary's discard a "cost"?

Asked by Drilnoth 10 years ago

So this situation came up and I was surprised to not find anything about it online.

Player A has Library of Leng out. The Gatherer rulings for Library specify that cards discarded to pay costs cannot be put on top of their controller's library with Library of Leng.

Player B has Painful Quandary out.

Can Player A put cards discarded to Painful Quandary on top of the library? I know that some cards which present an either/or choice such as this, like Blood Clock , specify "pay".

I'm about 75% sure that it is considered a cost (so the Library can't replace it) due to 117.12a, but A) 100% is not 75%; and B) I couldn't find the answer easily online, so it seems best to have an answer floating around so future askers can find it without delving into the comprehensive rules.

Devonin says... #1

Costs are paid to cast spells and activate activated abilities.

painful quandry is a triggered ability which generates an effect: a loss of 5 life or a discard of a card.

The Library of Leng can impact that discard.

May 13, 2014 11:55 p.m.

Devonin says... #2

Bah, Painful Quandary

May 13, 2014 11:56 p.m.

Drilnoth says... #3

Did you check 117.12 and 117.12a?

May 14, 2014 12:02 a.m.

Rhadamanthus says... Accepted answer #4

For effects written "Do X unless you do Y", Y is an optional cost that's paid as the effect resolves. Discarding a card for Painful Quandary is paying a cost, so Library of Leng can't replace it.

The relevant rules:
117.12. Some spells, activated abilities, and triggered abilities read, "[Do something]. If [a player] [does or doesn't], [effect]." or "[A player] may [do something]. If [that player] [does or doesn't], [effect]." The action [do something] is a cost, paid when the spell or ability resolves. The "If [a player] [does or doesn't]" clause checks whether the player chose to pay an optional cost or started to pay a mandatory cost, regardless of what events actually occurred.
117.12a Some spells, activated abilities, and triggered abilities read, "[Do something] unless you [do something else]." This means the same thing as "You may [do something else]. If you don't, [do something]."

Together they mean Painful Quandary's text is to be understood as "Whenever an opponent casts a spell, that player may discard a card. If that player doesn't, he or she loses 5 life."

May 14, 2014 12:09 a.m.