Yellow Mold for reference. Relevant text for question #1:
If disturbed, a 5-foot square of this mold bursts forth with a cloud of poisonous spores.
The mold is apparently distributed in 5' chunks. I have a module with a 15' x 30' wide swath of mold. The PCs will have to move over it. When they hit the first square, I understand that I trigger a burst, and the PC will need a saving throw. However, since the mold appears in a big huge block of many squares, when the PC moves into a 2nd square and I trigger another burst, do I ask the PC for a 2nd save? In other words, if the PC moves across the 15' wide chunk of mold, am I asking for 1 save for the whole thing as a single move action, or am I asking for 3 saves -- 1 for each square?
Relevant text for question #2:
All within 10 feet of the mold must make a DC 15 Fortitude save or take 1d3 points of Constitution damage.
Usually, spells with a radius are centered on a grid intersection. However, Paizo has this FAQ for effects that burst from a creature. Essentially, a 10 foot burst that is not a spell is not centered on a grid intersection, but on the creature's entire square instead, and you extend it out from there. Thus, a 10' burst would be 25' wide. That's odd, but that's the FAQ trying to make sense of a burst centered on a creature. So questions:
1. Are molds "creatures" enough to qualify for the FAQ effect?
2. The FAQ is talking about large & larger creatures that have burst effects that might not even cover them entirely if the radius is measured from a grid intersection. So, in order to cover the larger creature, they abandon the grid intersection and have the burst flow out from all edges of the creature's space. That makes sense, but then what about a 5' mold? It's not size large or larger. Even if you put down 50' worth of mold, you handle it in 5' blocks. So does its size disqualify it for this alternative measurement?
Are molds "creatures" enough to qualify for the FAQ effect?
No.
(Also, the PC would have to be pretty stupid to move into a second square after the first square exploded poison into his face.)
My gut feeling is that you need to make a single save for every round you spend inside the spore cloud, regardless of how many squares are disturbed. More squares disturbed means a larger area that is affected. You might also increse the duration of the lingering spore effect as well, in the case of multiple bursts.
But I wouldn't call for multiple saves per round.
If you really want to make getting a multiple burst effect really nasty, you could raise the DC by two for each additional "dose" of poison spore effect. IIRC that is the usual method for multiple doses of poison. IMHO, such an increase in virulence of the poison is unnecessary.
As far as measuring it, go with 10' (2 squares) beyond the edge of the disturbed squares of mold. That will save you having to adjudicate which grid intersection serves as the burst origin point. It'll also make it easier to determine the cloud area when multiple squares are disturbed.
(Also, the PC would have to be pretty stupid to move into a second square after the first square exploded poison into his face.)
There are enough cases of a character with a high fortitude save being willing to rush through the mold to get to the enemy wizard that it is worth asking.
Would this qualify for the +2 to the DC of a poison for every dose they are exposed to?
Remember, the +2 DC for multiple poison doses stacking is only supposed to apply to doses where you already failed the initial Fortitude save to be affected.
Re-reading the description of yellow mold, it doesn't really say how you handle it, meaning it's entirely up to the DM. You have three choices:
1) Keep the DC at 15, and simply enlarge the area affected (up to 10' from every burst square);
2) Keep the DC at 15, and increase the duration from 5 to 10 rounds (to 15, to 20, etc) for additional burst beyond the first; or
3) Increase the DC by +2 for each additional burst that you're affected by in a given square, or that you passed through on your turn of movement (which would require calculating each burst area separately).
Personally, I'd stick with solution (1), since it's the easiest to manage as a DM. But you're perfectly justified in using any combination up to and including all three, since the description never really specifies how to handle multiple bursts.
Remember, the +2 DC for multiple poison doses stacking is only supposed to apply to doses where you already failed the initial Fortitude save to be affected.
Or where several doses of an ingested poison are consumed at the same time. I never looking up if this applies to inhaled poisons also, which might be the best comparison.
My gut feeling is that you need to make a single save for every round you spend inside the spore cloud, regardless of how many squares are disturbed. More squares disturbed means a larger area that is affected. You might also increse the duration of the lingering spore effect as well, in the case of multiple bursts.
But I wouldn't call for multiple saves per round.
I think that's the case with Troglodytes and stuff though. 6 Trogs = 6 Saves. Some play it different, but's worth noting that if you instead combine the 6, you'll get a save that may be impossible (rather than statistically difficult.) And making it only a single save nerfs the creatures in question.
I'd say one save per patch crossed, but not per square of the burst.
[Note on design: If this is for a dungeon you're in or designing, consider looking/designing for alternatives to cross it. Monkey bar like structures, secret passage way, some squares don't have the mold but it makes you run a serpentine route, some squares are illusions of mold to be dispelled, there's a giant barrel of Mold Killing Stuff on one side of the room that could potentially be opened with arrows or telekinesis.]
Yellow Mold for reference. Relevant text for question #1:
If disturbed, a 5-foot square of this mold bursts forth with a cloud of poisonous spores.The mold is apparently distributed in 5' chunks. I have a module with a 15' x 30' wide swath of mold. The PCs will have to move over it. When they hit the first square, I understand that I trigger a burst, and the PC will need a saving throw. However, since the mold appears in a big huge block of many squares, when the PC moves into a 2nd square and I trigger another burst, do I ask the PC for a 2nd save? In other words, if the PC moves across the 15' wide chunk of mold, am I asking for 1 save for the whole thing as a single move action, or am I asking for 3 saves -- 1 for each square?
Per this FAQ, you can jump across this patch with a DC 15 acrobatics check.
Fly, Dim Door, and other spells work also.As oozes are also hazards like yellow mold, a Knowledge (Dungeoneering) check can identify it. DC 21. Tht will get you a bit of useful information like what fire and sunlight do to it.
Relevant text for question #2:
All within 10 feet of the mold must make a DC 15 Fortitude save or take 1d3 points of Constitution damage.
Each fail means your Fort save goes down by 1 (on average). Each failed save also means another round to save again, up to 5 additional times. As the save is worded like poison saves, I think the bump to the DC, extended duration, and so on is better than tracking multiple save sets.
You need to make a minimum of three checks to get past unless you jump.It is possible, if a player always fails the Fort save, that they will die due to con damage. They could have 18 checks max for three squares.
Another problem: nothing indicates this doesn't happen each round if disturbed each round.
/cevah