How Does Temporary Hit Points Stack?

[Arkhandus]

Temporary hit points stack. All the temporary hit points you have are added to your current HP total and subtracted normally when you're damaged, before your normal HP are taken away. Once the effect that granted them deactivates, any remaining temporary hit points from that effect disappear, but none of your normal hit points will be lost when they go away.

Temporary hit points are not listed as a bonus. Thus they stack just like an unnamed bonus would stack. There is no rule saying that temporary hit points don't stack, no rule saying they count as such-and-such-a-bonus.

Now, you CANNOT stack multiple Vigor powers, however. The rules for magic and the rules for psionics both state that you cannot stack the same spell effect or the same power effect on the same subject. Only one copy of a particular spell or power can be active upon a particular subject. Earlier copies of a spell effect or power effect remain dormant on the subject, while the most powerful or most recent is the only one to actually be active; once that one has expired, been dispelled, or whatever, the next most powerful or next most recent copy takes effect, if its duration hasn't run out already.

These are not opinions. The Magic chapter in the PH, and the similar chapter in the PsiHB and XPH, describe how/when spells or powers will overlap or stack. The descriptions for stacking/not stacking bonuses and penalties, and the description for temporary hit points, are just the way I've stated.

 

[nhl_1997]

Temporary hit points stack. All the temporary hit points you have are added to your current HP total and subtracted normally when you're damaged, before your normal HP are taken away. Once the effect that granted them deactivates, any remaining temporary hit points from that effect disappear, but none of your normal hit points will be lost when they go away.

Temporary hit points are not listed as a bonus. Thus they stack just like an unnamed bonus would stack. There is no rule saying that temporary hit points don't stack, no rule saying they count as such-and-such-a-bonus.

Now, you CANNOT stack multiple Vigor powers, however. The rules for magic and the rules for psionics both state that you cannot stack the same spell effect or the same power effect on the same subject. Only one copy of a particular spell or power can be active upon a particular subject. Earlier copies of a spell effect or power effect remain dormant on the subject, while the most powerful or most recent is the only one to actually be active; once that one has expired, been dispelled, or whatever, the next most powerful or next most recent copy takes effect, if its duration hasn't run out already.

These are not opinions. The Magic chapter in the PH, and the similar chapter in the PsiHB and XPH, describe how/when spells or powers will overlap or stack. The descriptions for stacking/not stacking bonuses and penalties, and the description for temporary hit points, are just the way I've stated.

The rules, as stated, seem to imply what you have just said. Unfortunately, those same rules as stated, do not explain what happens in this situation:

source A: grants X temporary hit points on subject 1 (who has 50 original hp)
source B: grants Y temporary hit points on subject 1
subject 1 takes Z damage
source A ends

How many hp and temporary hp does subject 1 have for each of these situations:
1) X = 10, Y = 5, Z = 3
2) X = 5, Y = 10, Z = 3
3) X = 10, Y = 5, Z = 8
4) X = 5, Y = 10, Z = 8
5) X = 10, Y = 5, Z = 12
6) X = 5, Y = 10, Z = 12

 

[Arkhandus]

Yes the rules explain that situation just fine. Temporary hit points are not like a barbarian's raging hit points. Damage suffered is subtracted from temporary hit points first. It does not carry over to normal hit points unless all THPs are removed through damage or whatever.

If Subject A has 20 hit points normally, gains 10 temporary hit points from Effect X, then gains 4 temporary hit points from Effect Y, he or she has 34 hit points at the moment. Subject A then gets smacked for 12 damage, reducing his HP to 22. Effect X and Effect Y are still functioning, but the THP from Effect X have all been taken away through damage, so Effect X is no longer granting any THP. Now say that Subject A avoids getting hurt any more that day, and Effect X and Effect Y run out of duration. Subject A is back down to his or her previous current HP of 20.

Alternate situation: Subject A gets into a fight the next day, and his or her allies buff 'em up again with another 10 HP from Effect X and another 4 HP from Effect Y. Subject A has 34 HP again. He or she gets smacked around by an ogre for 28 damage, ouch! Subject A has 6 HP left, and starts withdrawing while shouting for his or her allies to cover him. Subject A gets away safely, and both of the THP effects fade away eventually, leaving Subject A with 6 hit points still. Subject A, disgruntled but alive, meekly asks for healing from the friendly local cleric he or she always has to suck up to.

Another situation: Subject A is back in his/her prime again, some weeks after the previous battles, but winds up getting stuck in another fight for his/her life. Once again buffed with Effect X and Effect Y, Subject A has 34 hit points. Subject A gets hit for 8 damage, going down to 26 HP. Then, unexpectedly, an enemy wizard casts Dispel Magic and strips away Effect X! Subject A loses the 2 HP that were still around from Effect X, since Effect X was the highest-level spell buffing him, and thus it was the first victim of the Dispel. Subject A fights on, and defeats the wizard before Subject A could lose any more hit points. Once Effect Y ends, Subject A returns to having 20 hit points.

Now, if Effect X and Effect Y had been spells or powers of the same level, and if the Dispel could only take out one of them, whichever one was granting the superior benefit at the time would have been Dispelled first. Subtract damage from the temporary HP of the most-powerful effect first, as it has precedence. So the 10 THP from Effect X would be damaged first, and thus if Effect X's temporary hit points had been reduced to 3 HP because of a 7-damage attack, followed by a Dispel Magic, then effect Y would be dispelled instead, since it was granting more temporary hit points at the moment. Again, this assumes both Effects were the same spell/power level.

Final Situation: Subject A is, again, rather predictably caught up in another combat. Healed and buffed by his allies with the usual Effect X and Effect Y, he or she has 34 HP once more. Engaging a foe in combat, Subject A gets stabbed by a rogue from behind for 17 damage! Subject A calls out for assistance, then turns to move out of the flanking maneuver so he can take down the annoying rogue before any more sneak attacks get through. Subject A has 17 HP left, and his or her allies move in to get the other foe off his/her back. Taking out the rogue, Subject A is affected by another Dispel Magic, removing both Effect X and Effect Y; however, he already lost those temporary hit points, so the Dispel has no effect on his HP.

Assuming he hadn't taken any damage, though, and assuming that the Dispel was able to remove both Effect X and Effect Y, he'd have gone down to his unaugmented current HP of 20.

 

[Hypersmurf]

If Subject A has 20 hit points normally, gains 10 temporary hit points from Effect X, then gains 4 temporary hit points from Effect Y, he or she has 34 hit points at the moment. Subject A then gets smacked for 12 damage, reducing his HP to 22. Effect X and Effect Y are still functioning, but the THP from Effect X have all been taken away through damage, so Effect X is no longer granting any THP.

Why did the THP from Effect X get taken away first?

Subtract damage from the temporary HP of the most-powerful effect first, as it has precedence.

What's your justification for this 'precedence' rule? Where can it be found?

-Hyp.

 

[nhl_1997]

Another situation: Subject A is back in his/her prime again, some weeks after the previous battles, but winds up getting stuck in another fight for his/her life. Once again buffed with Effect X and Effect Y, Subject A has 34 hit points. Subject A gets hit for 8 damage, going down to 26 HP. Then, unexpectedly, an enemy wizard casts Dispel Magic and strips away Effect X! Subject A loses the 2 HP that were still around from Effect X, since Effect X was the highest-level spell buffing him, and thus it was the first victim of the Dispel. Subject A fights on, and defeats the wizard before Subject A could lose any more hit points. Once Effect Y ends, Subject A returns to having 20 hit points.

Now, if Effect X and Effect Y had been spells or powers of the same level, and if the Dispel could only take out one of them, whichever one was granting the superior benefit at the time would have been Dispelled first. Subtract damage from the temporary HP of the most-powerful effect first, as it has precedence. So the 10 THP from Effect X would be damaged first, and thus if Effect X's temporary hit points had been reduced to 3 HP because of a 7-damage attack, followed by a Dispel Magic, then effect Y would be dispelled instead, since it was granting more temporary hit points at the moment. Again, this assumes both Effects were the same spell/power level.

I do not think that the rules state anywhere (explicitly or implicitly through other similar situations) that....

If effect A provides 5 temp hps,
effect B provides 10 temp hps,
and the subject takes 7 damage,
that effect A is now providing 5 temp hps,
and effect B is now providing 3 temp hps.

Although that is a perfectly reasonable, it is an assumption you are making. Without that assumption, one could say that the temp hps granted by effect A are now gone and effect B is now granting 8 temp hps. The point is that if multiple sources of temporary hit points are allowed, then there must be some method to determine in what order those temp hps are removed when the subject takes damage.


Just trying to make sure I'm correctly understanding the priority order you laid out earlier. If it's easy enough, maybe I'll allow multiple temp hp sources should that situation ever arise.

1) First, apply damage to whichever effect presently grants the most temp hps
2) If tied, then apply damage to whichever effect is the highest spell level
3) If still tied, determine randomly?

Example:
a) false life providing 15 temp hps
b) greater heroism providing 15 temp hps
c) 10 damage
False life now provides 15 and greater heroism now provides 5.
d) 5 damage
False life now provides 10 and greater heroism now provides 5.

Next, that character is in an area (or targeted) greater dispel magic
e) dispel check against greater heroism fails
f) dispel check against false life succeeds ending that spell.
Greater heroism is still providing 5 temporary hit points.


Seems a little complicated, but only slightly more complicated than dispel magic in the first place. I'm just a bit hesitant to make it necessary to keep track of exactly how many temporary hps each effect is granting at each moment.

 

[Hypersmurf]

1) First, apply damage to whichever effect presently grants the most temp hps

If I were going to do that, I'd do it point-at-a-time...

So if you have your two sources each providing 15 THP, and you deal 10 damage, then after the first point of damage is taken off source A (determined randomly), source B is now providing more THP, so the second point comes off source B.

So after all 10 damage is applied, source A and source B are now both providing 10 THP.

However, I'm even more inclined to use the FAQ ruling, weird as it sounds, and have those two sources overlapping.

Let's say source C is providing 15 THP, and source D is providing 10. If 10 damage is sustained, the first 5 damage would come off source C, bringing it down to 10; the second 5 points would come off both source C and source D (since they overlap), leaving both sources providing 5 THP (overlapping, to give a hit point total 5 points higher than normal, not 10).

-Hyp.

 

[ARandomGod]

As I understand it, temporary hit points from the same source do not stack. Two seperate castings of the same spell are considered different sources, and therefore do stack.

Plus, let's face it, this is easier.

As for something like false life being really uber... well, I thought that originally too... but look at the power level of relative cure spells. False life is a level two spell... therefore we'd have to compare it to the level two divine cure. False life will do d10+10 (after level ten) and the cure spell will do 2d8+10).
So, false life = 11-20 HP's (ave 15.5) Divine healing = 13-26 HP (Ave 19.5)

Divine healing is better.
Now, there are of course differences. Divine healing is permanent...
False life will only be "permanent" iff you're damaged while it's up.

False life is better for one battle a day... divine healing is better forever.
False life is better before battle, lesser effective during, and near useless after.

Divine healing is useless before that one battle. Variable up to full effective during, and best after battle.

I wouldn't say that it's overpowered at all. In spite of the obvious ability to walk into battle with ... say 93 extra HP's (assuming you use six level two spells, at average effectiveness).

 

[Nail]

Temp. Hit Points are simple.

The rules governing how tHP from different sources interact are vague and needlessly confusing.

Arrrg!!!

If tHP overlap, then does that mean:

• Only the highest one counts, and the lower ones never apply,
  
• Only the highest one counts, until it becomes lower than one of the others....then the new "highest one" counts,
  
• Only the highest one counts, and damage taken is subtracted from all the sources simultaneously; this would leave the highest one always the highest one,
  
• All tHP stack, regardless of source.

Don't know about you, but that last option looks like the least trouble.

 

[Hypersmurf]

As I understand it, temporary hit points from the same source do not stack. Two seperate castings of the same spell are considered different sources, and therefore do stack.

Which is completely the opposite of what the 3E Main FAQ said...

Temporary hit points from the same source stack; two separate castings of the same spell are considered different sources, and therefore do not stack.

-Hyp.

 

[KarinsDad]

Which is completely the opposite of what the 3E Main FAQ said...

Temporary hit points from the same source stack; two separate castings of the same spell are considered different sources, and therefore do not stack.

I think this is a typo. The first part of that sentence is illogical. I suspect it means:

1) "Temporary hit points from different sources stack; two separate castings of the same spell are considered the same source, and therefore do not stack."

Then, combining this with rules from the book on spells:

2) "Same Effect More than Once in Different Strengths: In cases when two or more identical spells are operating in the same area or on the same target, but at different strengths, only the best one applies."

3) "One Effect Makes Another Irrelevant: Sometimes, one spell can render a later spell irrelevant. Both spells are still active, but one has rendered the other useless in some fashion."


As per my original example (using psionic Vigor instead of a spell):


Round 1: 2 PP in Vigor for 10 temporary hits.

Round 2: 2 PP in Vigor for 10 temporary hits. This power is irrelevant, rule #3 and does not stack, rule #1.

Round 3: Gets hit for 7 points. The first Vigor takes the 7 point hit and drops to 3. The other Vigor takes over (now being the stronger of the two) and maintains the temporary hits at 10. Rule #2 and Rule #3.

Round 4: Gets hit for 14 points. Takes 4 points of real damage. Rule #2. The first Vigor with 3 temporary hits remaining is the only Vigor left now. The second Vigor is gone.


Does this seem to match the rules?