No, it's not at stake because they are in a location where blood-catching vessels will be readily available and visible.
<snip>
What's actually at stake is the PC's ability to get the blood to the naga, not find a cup.
This is why I say that you do not seem to understand how BW works.
You are talking about
how likely something is based on some vision of the fiction. That is not what determines whether or not the dice are rolled in BW.
What determines whether dice are rolled is if (i) a player says that their PC does something, and (ii) the success or failure of that thing would
matter to some player-determined priority for that PC.
Here, the player said that his PC does something - ie look for a vessel to catch the blood - and whether or not he finds one
matters to whether or not he can catch the blood (because without a vessel, he can't catch the blood). It's that simple.
You may or may not like the rules - that's your prerogative - but it is a bit frustrating to have you continue to tell me that I applied them incorrectly. I have quite a bit of experience reading, playing and GMing this system. Whereas you seem to have none. So I don't really grasp your confidence in asserting how it is meant to work.
[/I]And
if the PC knew ahead of time he'd be called upon to gather blood,
then there should be no reason he wouldn't prepare himself for the task ahead of time
unless the game puts artificial constraints on PC actions in order to drive up drama, in which case allow me to link to the TV Tropes page "
Idiot Ball."
And that's something I consider to be a bad rule for what I assume is a serious or semi--serious game.
There are no "artificial constraints". But the PC was not carrying any vessels. He was planning to take the mage to the Naga intact - hence why he was hoping to get to the tower before the assassin did.
And there was no apparent opposition that was keeping the PC from catching the blood--there was an assassin, but no mention of the assassin attacking the PC, at least none that I can remember.
The assassin was in hand-to-hand combat with another PC. But there was something keeping the PC from catching the blood, namely, his lack of a vessel! That's why he looked around for one.
The PC isn't looking for a specific vessel or type of vessel (e.g., the naga didn't say it must be presented to it in a silver wineglass or a blessed cup take from the local church). The PC isn't looking for a vessel that has been hidden away, deliberately or accidentally. They're looking for any type of vessel that can hold liquid in a sick room that should logically have cups, bowls, jars, dishes, pots, and other such items.
The "logic" you refer to is why the obstacle is low rather than high.
Heck, he could have yanked off one of the decapitated NPC's shoes and had the blood drain into that.
Had he declared that action, it would have been resolved as an Agility test rather than a Perception test.
Which means that, from everything you have said, there was no actual in-game or character-driven pressure on the PC to obtain a cup, nor was there a time crunch. Any pressure in the scene was from GM fiat.
BW does not use a concept of "pressure" in order to determine if a test is required. I'm aware that some RPGs do use that notion. BW doesn't, though. It uses the concepts of "stakes" and "conflicts". The rulebook - in the bit that you can read for free - even includes the following statement (p 72):
as soon as a character wants something that he doesn’t have, needs to know something he doesn’t know, covets something that someone else has, roll the dice.
The character doesn't have a vessel, and wants one. I mean,
really wants one - his Belief is on the line. Roll the dice!
EDIT:
It occurs to me that you are assuming that a failed test means a failed task. But it needn't. It means failed intent.
Let's suppose that the roll was 4 dice against Ob 1, so a 1 in 16 chance of failure. If the test fails, what is the correct narration?
Given that the PC is a shaman who summons spirits, and one of his domains for summoning is Sickbeds, and he has a Belief that
To catch a thing, one must set the right bait, a possible narration of failure would be that he sees a vessel, but it is broken, having been knocked to the floor in the fighting that's taken place in the room. Bait him into trying to summon spirits to mend the vessel!