Calculated Dismissal — ruling 1

If the spell mastery ability applies, you’ll scry 2 even if the controller of the spell pays {3}.

Calculated Dismissal — ruling 2

In one unusual situation, you can cast Calculated Dismissal targeting an instant or sorcery spell you control while there is one instant or sorcery card in your graveyard. In this situation, if you decline to pay {3}, the spell will be countered and put into your graveyard. The spell mastery ability will then apply and you’ll scry 2.

Calculated Dismissal — ruling 3

Check to see if there are two or more instant and/or sorcery cards in your graveyard as the spell resolves to determine whether the spell mastery ability applies. The spell itself won’t count because it’s still on the stack as you make this check.

Calculated Dismissal : règles, fonctionnement et interactions (MTG)

Calculated Dismissal is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Counter target spell unless its controller pays . Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, scry 2. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

How it works : Calculated Dismissal

Original English text — Wizards of the Coast / Scryfall

#1June 22, 2015· Wizards of the Coast
If the spell mastery ability applies, you’ll scry 2 even if the controller of the spell pays .
No other card is named in this ruling.
#2June 22, 2015· Wizards of the Coast
In one unusual situation, you can cast Calculated Dismissal targeting an instant or sorcery spell you control while there is one instant or sorcery card in your graveyard. In this situation, if you decline to pay , the spell will be countered and put into your graveyard. The spell mastery ability will then apply and you’ll scry 2.
No other card is named in this ruling.
#3June 22, 2015· Wizards of the Coast
Check to see if there are two or more instant and/or sorcery cards in your graveyard as the spell resolves to determine whether the spell mastery ability applies. The spell itself won’t count because it’s still on the stack as you make this check.
No other card is named in this ruling.