Timing for moving blood to Progeny or Creation Rites

Do I have to announce if and how much blood is moved to the Progeny or Creation Rite when playing the card?

If so, what happens if I do not have that blood anymore during resolution? For example, my Prince with Obfuscate has two blood. I play Progeny, announce that I will move one blood to the Progeny (during resolution). But I have to play Forgotten Labyrinth (costs a blood) to make the action successful, so I have no blood left for moving it the Progeny.

Third Tradition: Progeny, The
Action
1 blood
Requires ready Prince or Justicar. +1 stealth action. Put this card in play; it becomes a 1 capacity vampire. Go through your library, ash heap, or hand to find one Discipline card for this card. Move up to 2 blood from the acting vampire to this card. This vampire is not considered unique, cannot act the turn it is created, and is the same clan as the acting vampire.

Creation Rites
Action
1 blood
Requires a ready non-Sterile archbishop, priscus or cardinal. +1 stealth action. Put this card in play; it becomes a 1 capacity vampire. Go through your library, ash heap or hand to find a Discipline card for this card. You may move a blood from the acting vampire to this card. This vampire is not considered unique, cannot act this turn, and is the same clan as the acting vampire. Reshuffle your library afterward.

You don't have to announce if you will be moving blood (or how much you will be moving) on Creation Rites / Embrace / Third Tradition: Progeny, Abomination, Bamba, The Becoming, Dual Form.
I'll find a reference for that (or this will be the reference).

An explanation reference would be nice, because I wonder why you don't have to announce it, when usually you have to announce all of the effects of the card. There are exceptions to this e.g. for Political Actions, actions to enter combat or where you search your library for something.

extrala wrote:

There are exceptions to this e.g. actions to enter combat

Wuuuuuuh?

jamesatzephyr wrote:

extrala wrote:

There are exceptions to this e.g. actions to enter combat

Wuuuuuuh?

What I meant was, that you don't have to announce if/when you want to use the optional maneuver when announcing a Bum's Rush or some similar card.

As I understand it, the "search for discipline master and move blood" part is an effect triggered by the card being put in play (since it occurs after the becomes a vampire), so it's not part of the action. There's a similar ruling about when you decide on the cards being recycled from Ashur Tablets here