I had a table discussion about how to handle waking up naturally sleeping creatures. I looked here and found this really good [answer] but I feel it is not RAW. I will explain what I mean here and will mark answered the one that will address my concern. thank you.
natural sleep is considered unconscious by XGE p.77
While a creature sleeps, it is subjected to the unconscious condition
and as suggested in DMG p.248
if a character is in a state such as sleep, that lacks consciousness, you can say the character is unconscious.
Unconscious condition states that you incapacitated and you are unaware of your surroundings in the Conditions description of PHB p.292
Incapacitated PHB p.290 states you can’t take actions or reactions
Wisdom (perception) is defined in PHB p.178 by this
Your Wisdom (Perception) check lets you spot, hear, or otherwise detect the presence of something. It measures your general awareness of your surroundings and the keenness of your senses.
This in itself by the rule means you can’t make a perception check while sleeping (incapacitated) and your passive perception does not work (unaware of your surroundings where perception measures your awareness of it) Now, XGE p.77 adds that you can break the unconscious condition by waking up the sleeping creature through
- Sudden loud noise (continual loud noise, like trying to sleep next to a large waterfall, won’t stop you from sleeping nor wake you up)
- someone uses an action to shake or slap you
- someone speaks at normal volume while the environment is silent (not even crickets sounds) and the passive perception of the sleeping creature is 15 or more
- someone whispers (so, speech at low volume but you can adjudicate it as you which since this is not written, as long as the someone says he is whispering) within 10′ of the sleeping creature who has a passive perception of 20
- the sleeping creature takes any damage
As the previous answer I linked above suggests, the discussion goes about being able to perceive any sound. The rule as written specifies that only speech or whisper with each their condition would wake up a sleeping creature and that the creature is still unconscious and unaware of its surroundings so can’t use a passive perception skill other than the exception marked by the said rule. Which also would mean that only damaging spells can wake a sleeping creature as PHB of.204 under Targets state the following
Unless a spell has a perceptible effect, a creature might not know it was targeted by a spell at all. An effect like crackling lightning is obvious, but a more subtle effect, such as an attempt to read a creature’s thoughts, typically goes unnoticed, unless a spell says otherwise.
since you are unaware of your surroundings and perception is its measure which allows you to be aware of perceptible things/effects, you can’t ever perceive it. Thus someone casting cure light wounds on you in an environment that is not silent and you don’t have a passive perception of 20 (since the spell is touch and thus within 10′) won’t wake you up.
(emphasis mine for clarity in the argument)
thanks for reading and clarifying what is RAW and if, though a fair ruling of the situation, the linked answer would be RAI. : Perception While Sleeping