Nocturn + Mouthpiece + Conditioning

I would have to disagree with this. There is a window after an action is blocked but before combat begins during which action modifiers can be played. See cards such as Venenation, Power of One and Change of Target for examples of cards that can explicitly only be played during this window.
My understanding (based on this post about Venenation) is that the blocker would be tapped before you reach this window.

Mael wrote:

I would have to disagree with this. There is a window after an action is blocked but before combat begins during which action modifiers can be played. See cards such as Venenation, Power of One and Change of Target for examples of cards that can explicitly only be played during this window.

This is incorrect, re:the rulebook that I quoted. The reason these cards that you mention can be played at that time is that they have explicit text stating that they can be played at that time. Once the action is blocked, you can only play combat cards, excepting card which have specific text stating otherwise.

However: There is a window after a block attempt has been declared but before the action is declared blocked in which action modifiers can be played.

Usually, that's when Lost in Crowds, sup' Bonding, et al. get played. But feel free to play Mouthpiece + Conditioning and no stealth.

KevinM wrote:

Mael wrote:

I would have to disagree with this. There is a window after an action is blocked but before combat begins during which action modifiers can be played. See cards such as Venenation, Power of One and Change of Target for examples of cards that can explicitly only be played during this window.

This is incorrect, re:the rulebook that I quoted. The reason these cards that you mention can be played at that time is that they have explicit text stating that they can be played at that time. Once the action is blocked, you can only play combat cards, excepting card which have specific text stating otherwise.

Their text restricts them to only being played during that window, which illustrates the existence of that window.

Re the rulebook that you referenced, the text reads "If the action is blocked .... the blocking minion is tapped and enters combat ...". It does not say that the action is unsuccessful. It also does not say that no further action modifiers can be played (indeed there are others that can only be played after the combat).

If you treat "is tapped" and "enters combat" as two separate steps that normally happen sequentially, then we can infer a window between them for action modifiers to be played before the "enters combat" portion of the action begins.

The rulebook is unclear whether these should be treated as separate sequential steps, or as a single step, but the related ruling that I linked does provide clarity on that.

If you have a ruling that contradicts my reading of this, please do provide it.

floppyzedolfin wrote:

However: There is a window after a block attempt has been declared but before the action is declared blocked in which action modifiers can be played.

Correct. But that isn't what I keep responding to. Once the action is blocked, you cannot play action modifiers, except via explicit card text.

i.e. When the acting Methuselah states "You successfully blocked" then she may no longer play action modifiers, except via explicit card text.

Venenation requires a successful block before being played. So the 'before this action is blocked/before blocks are successful' window is long-closed.

The play sequence (for the Nocturn Sequence):

Vamp X has declared a block attempt to block Nocturn
Now other action modifiers can be played (such as stealth cards)
The Nocturn would now be blocked once the acting Methuselah passes on impulse and the blocking Methuselah does so as well.
Then the block is successful and the minion taps for blocking.
Then combat begins.

So in the space before you started the block attempt and the block being declared successful by both Methuselahs, there is space to play Mouthpiece, etc. If somehow the Nocturn cannot continue the action or dies, the action ends unsuccessfully, the block fails (since there is nothing to block) and the blocking minion untaps.