转一段规则原文好了
Temporary Hit Points
Through magic or the use of special abilities, a creature can
gain a number of hit points called temporary hit points.
When a creature gains temporary hit points, note its current
hit point total. If the temporary hit points go away through
a means other than damage, the creature’s hit points drop to
its current hit point total. If the creature has taken damage so
that its hit points are equal to or lower than the noted current
hit point total when the temporary hit points go away, all the
temporary hit points have already been lost. The creature’s
hit point total doesn’t drop further.
Temporary hit points gained from multiple applications
of the same effect don’t stack. Instead, the highest number
of temporary hit points gained from that effect apply.
If temporary hit points are gained from multiple, different
sources that stack, keep track of those sources and when they
were gained separately. Any damage taken is first subtracted
from the oldest effect that granted temporary hit points.
When those are gone, subtract damage from the next oldest
effect, and so on.
When temporary hit points are lost, they can’t be restored
like normal hit points can be, even by magic.
