Diseases and Poisons

[SirShua]

Do the different stages of a disease or poison stack? For example So would a character at the debilitated state of a physical disease still suffer the effects of being impaired?

Also how do diseases or poisons affect creatures with regeneration? Do they still suffer from states such as physical blindness in the blinding sickness (CRB 418) or demon fever's impaired stage? Do creatures with regeneration actually die if they reach the death state?

[Metaphysician]

Given that diseases and poisons don't cause hit point loss, I would assume that yes, they totally can kill a creature with regeneration.

As for whether disease/poison states stack, my inclination would be "no". Each disease and poison tracks independently, so if your unlucky enough to be suffering from multiple at once, you don't just skip straight to dead.

[Nixitur]

I think you misunderstood the question about stacking, Metaphysician. It's not whether different poisons/diseases stack and move you down a single track. The question is whether, if you're suffering from a single affliction, you still suffer from all effects of previous stages when you're at a specific stage.
And the answer to that is yes.

CRB wrote:

Success could help the victim recover (see Curing an Affliction below); failure means that the victim moves one step further along its progression track, gaining the effects of the next step and keeping all previous effects.

Stacking of different afflictions is another matter entirely and far more tricky. We know that if you're exposed to multiple doses of the same poison, you have to make saves for both and move down the same track with each failed save. Which means that, yes, you're moving down two steps at the listed frequency if you're unlucky.

Now, whether two different, say, Intelligence poisons or physical diseases progress on the same track, I'm not quite sure. However, I would assume no partially because of this wording:

CRB wrote:

If the affliction has a progression track, she is no longer considered healthy with respect to that affliction

This implies that afflictions are tracked separately. Furthermore, some diseases and poisons have "special" progression tracks, so it wouldn't make much sense for two poisons with different tracks to interact on the same one.

Now, this means that if the second disease or poison you're exposed to is less severe than the first one, it doesn't actually do much except make you harder to heal. After all, on the standard Mental Disease track, if you're Befuddled, another disease making you Impaired doesn't matter at all because that includes all previous effects.

[SirShua]

Thanks for the clarification guys! I might have the regenerating creature lose it's permanent afflictions if it's cured, but I see your point about it dying.

Nixitur answered the question about previous effects stacking pretty clearly.