If you have the drained 1 condition and you gain drained 1 again, is it drained 2?

[Sardaukar]

Do conditions like Drained stack? For example, if you already have the Drained 1 condition and you receive the Drained 1 condition again, do you stay at Drained 1 or does it stack with the previous and go to Drained 2?

Looking at the Giant Viper in the 2e Bestiary, Stage 2 of the poison includes "1d6 poison and drained 1". If after you reach Stage 2 and then you fail your fortitude save again, do stay at Drained 1 or do you advance to Drained 2?

[Krysgg]

Unless it specifies otherwise (which a few creatures do) when you acquire redundant conditions you only suffer the worst (although if they have different durations you may need to track both). So in the case of viper poison you are only drained 1.

See redundant conditions of pg 623 in the crb

see the Shadow for an example of a condition that does stack (steal shadow)

[Aratorin]

No, conditions do not stack.

Pg. 623 wrote:

REDUNDANT CONDITIONS

You can have a given condition only once at a time. If
an effect would impose a condition you already have,
you now have that condition for the longer of the two
durations. The shorter-duration condition effectively
ends, though other conditions caused by the original,
shorter-duration effect might continue.
For example, let’s say you have been hit by a monster
that drains your vitality; your wound causes you to be
enfeebled 2 and flat-footed until the end of the monster’s
next turn. Before the end of that creature’s next turn, a
trap poisons you, making you enfeebled 2 for 1 minute. In
this case, the enfeebled 2 that lasts for 1 minute replaces
the enfeebled 2 from the monster, so you would be
enfeebled 2 for the longer duration. You would remain
flat-footed, since nothing replaced that condition, and it
still lasts only until the end of the monster’s next turn.
Any ability that removes a condition removes it
entirely, no matter what its condition value is or how
many times you’ve been affected by it. In the example
above, a spell that removes the enfeebled condition from
you would remove it entirely—the spell wouldn’t need to
remove it twice.

Redundant Conditions with Values
Conditions with different values are considered different
conditions. If you’re affected by a condition with a
value multiple times, you apply only the highest value,
although you might have to track both durations if one
has a lower value but lasts longer. For example, if you
had a slowed 2 condition that lasts 1 round and a slowed
1 condition that lasts for 6 rounds, you’d be slowed 2 for
the first round, and then you’d change to slowed 1 for
the remaining 5 rounds of the second effect’s duration. If
something reduces the condition value, it reduces it for
all conditions of that name affecting you. For instance, in
this example above, if something reduced your slowed
value by 1, it would reduce the first condition from the
example to slowed 1 and reduce the second to slowed 0,
removing it.

[nick1wasd]

Thing's like King's Sleep, Vampires, and Shadows state that their Drained is cumulative, so if it doesn't explicitly state that, it doesn't.

[Draco18s]

Note that it may not stack infinitely even when it does stack. IIRC shadows stack to 2 and greater shadows stack to 4.

[Ravingdork]

Along with a few others, I was pretty vocal on the First Edition forums about how you could layer multiple instances of a spell effect in order to defeat things like a single casting of dispel magic.

Looks like somebody was paying attention. :P