How Does Temporary Hit Points Stack?

[KarinsDad]

Say you have a Psion who puts 2 PP into Vigor multiple times. How does this work?

Example:

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

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

Round 3: Gets hit for 7 points. One of the two Vigors 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.

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

Is this correct?

Is there actually a rule for this (I couldn't find a temporary hits stacking rule, but assumed it was like other similar spells where the more powerful effect takes precedence)?

Or is it more or less DM discretion?

 

[Altamont Ravenard]

The manifester gains 3 temporary hit points per manifester level (maximum 18 hit points). These hit points do not stack with temporary hit points from other sources or with additional uses of vigor.

IMO, you can't have 2 Vigors active, plain and simple.

If you have 2 effects that grant you a different amount of temporary hit points, then you consider the effect that grants you the most temporary hit points, and forget about the other, ie if you have +15 hp from one source and +10 from another, and you get hit for 7 points of damage, you have 8 temporary hp left, not 7 from one source and 10 from the other, or 15 from the first source and 3 from the other.

The SRD doesn't say much about stacking temporary hit points, though.

AR

 

[nhl_1997]

Personally, I do not allow temparary hit points to stack or overlap simply because it's the easiest thing to do. However, we can attempt to look at the actual rule....

Temporary Hit Points (p. 146 PHB)
Certain effects, such as the aid spell, give a character temporary hit points. When a character gains temporary hit points, note his current hit point total. When the temporary hit points go away, such as at the end of the aid spell's duration, the character's hit points drop to his current hit point total. ...

Suppose your psion originally had 30hp.

The first vigor results in 10 temp hp and a note: "Vigor 1 original: 30"
----- hp: 30
----- temp hp: 10

Now let the psion take 6 damage.
----- hp: 30
----- temp hp: 4

The psion uses vigor again: "Vigor 2 original: 34"
----- hp: 30
----- temp hp: 14

Let the psion take 8 more damage.
----- hp: 30
----- temp hp: 6

Now, suppose someone casts dispel psionics (if the vigor effect cannot be dispelled, then change the example to aid and use dispel magic). Suppose the first vigor is dispelled but the second one is not. Since the psion's original hit point total was 30 when the vigor was first applied and now its effect has ended, hit hit point total drops to 30:
----- hp: 30
----- temp hp: 0

I'll reply with a second post with at least one (more reasonable) alternative method without the outright banning of stacking / overlapping temporary hit points

 

[MerakSpielman]

There seems to be some division on the concept of stacking temporary hit points. Some people think False Life is the greatest spell, since you can cast it several times and get a huge sum of temporary hit points, while others insist it wouldn't stack.

But it seems clear to me that if you're recieving temporary hit points and allowing them to stack, they should simply add on to the total. If you get two infusions of 10 temporary hit points, then you have 20 points total, and where they came from is irrelivent.

 

[nhl_1997]

Even if I were to follow the example I list below, I would still not allow temporary hit points from the same source to stack or overlap. Just take the most beneficial one and ignore all other temporary hit points from the same source.

I do not know much about psionics, so I'll attempt to illustrate the example via false life and greater heroism. The example character is a 15th level wizard with 91 hit points.

Beginning of the day, cast an extended false life (roll a 7)
----- hp: 91
----- temp: 17

Begin combat and the wizard takes 10 points of damage
----- hp: 91
----- temp: 7

Wizard casts greater heroism
----- hp: 91
----- false life temp: 7
----- greater heroism temp: 15

Wizard takes another 12 points of damage
----- hp: 91
----- false life temp: 7
----- greater heroism temp: 3
Note, the damage was applied to the greater heroism temporary hit points because that is the most recent effect.

Targeted greater dispel magic fails to dispel the greater heroism but successfully dispels the false life
----- hp: 91
----- greater heroism temp: 3

Wizard takes another 20 points of damage
----- hp: 74
Note, the morale bonuses from greater heroism are still in effect.


This method is certainly reasonable, but it's a bit cumbersome because it's necessary to keep track of how many temp hit points are remaining from each effect and the order in which the effects began.

 

[KarinsDad]

I'm not sure order of effects is relevant (i.e. I do not remember any other rules where order of effect is used).


I also think that the normal stacking rules tend to overrule:

+10 = 10
+10 = 20
+10 = 30

in the case of the same spell or power being used.


I do think that if the source of the effect is different and it is an unnamed bonus (i.e. not an enhancement bonus for example), then the stacking does occur. Using nhl_1997's example:

Cast False Life: temp hp = +7 = 7
Cast Greater Heroism: temp hp = +15 = 22

The reason is due to the fact that these are different sources of temporary hit points which do not name the "bonus". Granted, temporary hit points are not exactly a bonus, but we have few related rules to work with here.


I guess my real question comes down to whether you can use the power multiple times and just use the current best at any given point in time. You can use other spells multiple times (e.g. Protection From Evil 5 times if you want) and all of the spells work, but do not stack. If you do Dispel Magic, you have to dispel all of the spells to get the effect to go away.


I'm basing my answers above on:

"Different Bonus Names: The bonuses or penalties from two different spells stack if the modifiers are of different types. A bonus that isn't named stacks with any bonus.

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.

Same Effect with Differing Results: The same spell can sometimes produce varying effects if applied to the same recipient more than once. Usually the last spell in the series trumps the others. None of the previous spells are actually removed or dispelled, but their effects become irrelevant while the final spell in the series lasts.

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."


Do other people interpret this the same way?

 

[MerakSpielman]

I was told in a different thread that you can't dispel temporary hit points that are granted as the result of a spell any more than you can dispel the hit points gained when you are affected by a healing spell.

 

[Hypersmurf]

I've only ever seen the issue of stacking temporary hit points addressed in one place: the 3E Main FAQ.

And the answer is freaky-weird.

How is the body feeder weapon quality supposed to work?
Do the temporary hit points from the weapon stack? The
same question applies to mind feeder weapons and to spell
effects, such as vampiric touch.

Temporary hit points from a body feeder weapon stack with
each other, but not with temporary hit points from any other
source. Likewise, temporary psionic points from a mind feeder
weapon stack, but not with temporary psionic points from any
other source.

In general, any effect that allows you to gain temporary hit
points over time allows you to stack those points, but only
those points. For example, if you use the vampiric touch spell,
the temporary hit points you gain from that particular casting of
the spell stack. They don’t stack with the temporary hit points
you get from an aid spell, nor would the effects of two
vampiric touch or aid spells stack. If you were to use two body
feeder weapons (or two mind feeder weapons), you could not
stack the temporary points from the two weapons.

-Hyp.

 

[nhl_1997]

I'm not sure order of effects is relevant (i.e. I do not remember any other rules where order of effect is used).

Unfortunately, if you choose to allow multiple sources of temporary hit points, then there needs to be some sort of method to determine which source is the "active" one. The method you listed in the original post certainly seems reasonable: (summarizing below)

Whenever a character takes damage while having temporary hit points, the damage is first applied to whichever source is presently granting the most temporary hit points.

What happens if there is a tie? As long as there is some method of determining which source(s) absorb damage, then things might work.

Additionally, I personally think that if a character takes enough damage to overcome the larger temp hp source, another source should also be reduced. If someone has temporary hit points, then all damage is first applied to those temporary hps (instead of having an attack bypass the secondary source as you did in the original post.)

It's because of all these potential confusion points that I would not allow multiple temporary hit point sources.


By the way, there is at least one area where the rules explicitly state that order matters (so it's not completely insane to say that order of the spells determines the order in which temp hps are used.) If a character decides to wear multiple cloaks (or multiple gloves, more than two rings, etc.) then only the first cloak functions properly.

 

[nhl_1997]

I was told in a different thread that you can't dispel temporary hit points that are granted as the result of a spell any more than you can dispel the hit points gained when you are affected by a healing spell.

Although you cannot explicitly dispel the temporary hit points granted by a spell, the spell itself can be dispelled. The PHB clearly states that temporary hit points from a spell go away when the spell ends (see p. 146 of PHB). Since dispelling the spell ends it, the temporary hit points also must go away.

One cannot, however, dispel temporary hit points granted by certain supernatural effects (such as undead gaining temporary hit points for each negative level they bestow.)