This was a real call I fielded this past weekend at GP Louisville. I thought I'd nailed it but brought it to my peers' attention anyway and there is some disagreement about how it should have been ruled.

Andy Thought Scours himself.
Andy reveals the top card of his library as Progenitus. The second card remains unknown. Judge is called.
Players want to know if Andy should shuffle Progenitus into his deck before milling the second card from Library to the Graveyard.

Thinking of Dredge interactions with card draws, I think that each card going to the GY is an individual event and make the ruling that Andy should shuffle Progenitus into his Library before milling the second card from Thoughtscour.

After bringing this to my peers, they point out that the difference between the two situations is that Dredge has CR 120.2 to reinforce the fact that card draws are individual events, while milling multiple cards as individual events is not supported this way in the CR.

Originally posted by CR 120.2:

Cards may only be drawn one at a time. If a player is instructed to draw multiple cards, that player performs that many individual card draws.

Is it correct to “port” this CR 120.2 ruling into milling as well? Or is milling multiple cards as one effect considered to be one singular event?

Warmest Regards,
Russell D.




Edit - After some additional scouring of my thoughts, I realize that each instance of card milled must be considered it's own event or we would not be able to properly resolve Helm of Obedience and similar abilities that check what is milled. I will leave this post here to point out that there is currently no support for this situation in the CR.

Edited Russell Deutsch (Jan. 9, 2017 12:11:11 PM)

If a player is instructed to put multiple cards from a library to a graveyard, all such cards are moved simultaneously by default; while many players when instructed to mill will do so by moving single cards one by one into the graveyard, this is not technically correct–all such cards in fact move from the library to the graveyard at the same time.

Since Thought Scour puts both cards into the graveyard at the same time, the correct ruling in this situation would have been that the card below Progenitus before the shuffle is put into the graveyard, not the top card after the shuffle.

Helm of Obedience is the only exception to this default; since it instructs the player to put cards from the library into the graveyard “until” a card with certain characteristics is put into the graveyard, those cards must therefore be put into the graveyard one at a time. Helm is in fact the only card that works this way–superficially similar cards such as Balustrade Spy or Mind Funeral instead have the player reveal cards from the top (one by one) until certain conditions are reached, and then place the revealed cards into the graveyard simultaneously.

EDIT: Spelling correction

Edited Callum Milne (Jan. 26, 2017 08:17:50 PM)