First, the aspects of the character in question:
Invulnerable Rager
Invulnerability: At 2nd level, the invulnerable rager gains DR/— equal to half her barbarian level. This damage reduction is doubled against nonlethal damage.
Guarded Life
Benefit: While raging, if the barbarian is reduced below 0 hit points, 1 hit point of lethal damage per barbarian level is converted to nonlethal damage. If the barbarian is at negative hit points due to lethal damage, she immediately stabilizes.
Greater Guarded Life
When using the guarded life rage power, 1 additional hit point of lethal damage per barbarian level is converted to nonlethal damage.
So, let's use some round numbers - let's say a 20th level Barbarian with DR 20/- from various sources (Extra DR, Stalwart, etc.) which is doubled (DR 40/-) vs. non-lethal damage. Assume that he's raging and has 20 hit points left. He's hit for 50 lethal damage and... what happens?
This has been a very hotly debated topic in our group with several interpretations vieing for supremacy. I figured I'd get the consensus here to balance the equation.
First, make sure all your boosts actually add to your invulnerable rager DR, and don't just give separate DR (even if it stacks), though this is irrelevant to the example you gave (you didn't take nonlethal damage).
Then you take 30 lethal damage and would normally go to -10, but low and behold, Guarded lifes both trigger, and it's all converted to nonlethal damage and you're unconscious. If you don't have a way of maintaining your rage, you now lose 4 points of con, which makes you lose 40 HP. This puts you at -20 HP and would kill you if your con wasn't 21+, but wait, Guarded life still has something in the tank - it converts 10 more points to nonlethal damage. You automatically stabilize and live! Unless you were an unlucky barbarian with minimum HP (31) and a 11 con, which would mean 9 of those HP became lethal again, and you are now at -19 and dead.
At least that's how I read it.
Invulnerable ragers double versus non-lethal doesn't help versus guarded life. There was a big thread about it already. The gist is damage reduction only works versus weapon attacks, and guarded life kicks in after damage reduction applies, and is not a weapon attack.
First, make sure all your boosts actually add to your invulnerable rager DR, and don't just give separate DR (even if it stacks), though this is irrelevant to the example you gave (you didn't take nonlethal damage).
Then you take 30 lethal damage and would normally go to -10, but low and behold, Guarded lifes both trigger, and it's all converted to nonlethal damage and you're unconscious. If you don't have a way of maintaining your rage, you now lose 4 points of con, which makes you lose 40 HP. This puts you at -20 HP and would kill you if your con wasn't 21+, but wait, Guarded life still has something in the tank - it converts 10 more points to nonlethal damage. You automatically stabilize and live! Unless you were an unlucky barbarian with minimum HP (31) and a 11 con, which would mean 9 of those HP became lethal again, and you are now at -19 and dead.
See, that's interesting because this is the first time I've heard the interpretation that if any of the damage is converted to non-lethal then all of it is. The way it reads seems to suggest that its a one-to-one thing - i.e. only the damage that would take him below zero is converted to non-lethal.
Of course, following that logic, it would work out something more like this:
50 points of lethal damage is reduced to 30 by the DR 20/-, the Barbarian then takes 20 points of lethal damage which brings him to zero before the rest of it is converted to non-lethal against which the Barbarian has DR 40/-, keeping him at zero.
@Glutton
That's equally interesting, as I've never heard it stipulated that once Guarded Life converts lethal weapon damage to non-lethal weapon damage, its no longer considered weapon damage and therefor bypasses the Barbarian's DR - as if by converting it, the feat itself was actually somehow the source of the damage... although there's nothing about the Barbarian's DR or the feats themselves that say it only applies to non-lethal damage from weapons in the first place.
Do you have a link to this thread you refer to?
You take weapon damage, it is reduced by your DR. If that damage takes you below 0 hp, then Guarded Life kicks in and converts some of it to nonlethal damage. You don't get to apply DR twice.
See previous threads as Glutton mentioned. Just search up "invulnerable rager guarded life" on the messageboards. This has come up multiple times.
EDIT:
That's equally interesting, as I've never heard it stipulated that once Guarded Life converts lethal weapon damage to non-lethal weapon damage, its no longer considered weapon damage and therefor bypasses the Barbarian's DR - as if by converting it, the feat itself was actually somehow the source of the damage... although there's nothing about the Barbarian's DR or the feats themselves that say it only applies to non-lethal damage from weapons in the first place.
To expand on my initial comment, I think you may be confused on the order of operations. This is why Guarded Life won't work the way you'd like for an invulnerable rager:
- 20th lvl invulnerable rager gets hit by an attack, taking 20 lethal damage and 0 nonlethal.
- His DR 10/- vs. lethal and DR 20/- vs. nonlethal reduces that to 10 lethal damage.
- Damage is now applied.
- If this damage reduces the invulnerable rager's hp below 0, his Guarded Life rage power converts up to 20 hp of that damage to nonlethal.
You take weapon damage, it is reduced by your DR. If that damage takes you below 0 hp, then Guarded Life kicks in and converts some of it to nonlethal damage. You don't get to apply DR twice.
See previous threads as Glutton mentioned. Just search up "invulnerable rager guarded life" on the messageboards. This has come up multiple times.
EDIT:
That's equally interesting, as I've never heard it stipulated that once Guarded Life converts lethal weapon damage to non-lethal weapon damage, its no longer considered weapon damage and therefor bypasses the Barbarian's DR - as if by converting it, the feat itself was actually somehow the source of the damage... although there's nothing about the Barbarian's DR or the feats themselves that say it only applies to non-lethal damage from weapons in the first place.To expand on my initial comment, I think you may be confused on the order of operations. This is why Guarded Life won't work the way you'd like for an invulnerable rager:
- 20th lvl invulnerable rager gets hit by an attack, taking 20 lethal damage and 0 nonlethal.
- His DR 10/- vs. lethal and DR 20/- vs. nonlethal reduces that to 10 lethal damage.
- Damage is now applied.
- If this damage reduces the invulnerable rager's hp below 0, his Guarded Life rage power converts up to 20 hp of that damage to nonlethal.
You said 'that damage' - is there some basis for it, since guarded life doesn't actually say that? It makes more sense to me, but I was interpreting literally.
For instance, if you're brought to 1 hp out of your 100 hp, and then take 2 more, does guarded life kick in and convert 20 to nonlethal (if you're 20th level)? It's worded like it does, but this makes no sense for RAI. Or only 2 damage becomes nonlethal? I interpreted it more liberally only because of how harsh losing your rage is on your HP total.