Arkhandus
First Post
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.
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.