Suppose I, a wizard, am making camp for the night, and I want to have my owl familiar (obtained via the find familiar spell) keep watch while I sleep and wake me if anyone approaches. Since my familiar and I can communicate telepathically, can my familiar use this mental link to wake me up silently, or will it have to wake me the old-fashioned way, with extremely loud screeching?
[RPG] Can a wizard’s familiar wake the wizard using its telepathic link
dnd-5efamiliarsspellstelepathy
Best Answer
The question can be split in two related questions:
1. Yes
This was already answered here (related here as well). In particular, the spell states
From Rubik's answer for the first linked question,
So, ultimately, yes, the familiar can try to wake you up.
2. Maybe. Probably not. It's completely up to the DM.
First, let's check XGtE for the Sleeping rules. (Also, related question)
Telepathy is not loud noise, though. It's up to your DM if they work the same.
Also, check the Alarm spell.
Note that it is explicitly stated that the ping wakes you up. From that, it could be inferred that usually a "mental ping" would not wake you up. Would a telepathic scream wake you up? Maybe.
Ultimately, for balance purposes, this way of using Find Familiar overlaps a little with the utility of Alarm spell, which could be a reason for not allowing it. The Alarm spell is guaranteed, though (doesn't depend on a perception check), so it's not useless even if Find Familiar can be used this way.