How fast is telepathic communication (with a familiar)?

The spell description of the spell find familiar states:

While your familiar is within 100 feet of you, you can communicate with it telepathically.

Which to me raises a question: how fast is this communication?

Speed is often defined in latency – delay until the first bit of information arrives – and throughput – amount of information per second.

I believe I can be quite sure that the latency will be no less than that of regular speech which at 100 feet is next to nothing1

But when it comes to the throughput I seem to be in the dark – how quicly can concepts be explained through telepathic comunication?

This becomes important especially in the case of familiars when looking at surprise rules.

A member of a group can be surprised even if the other members aren’t.

So, the familiar’s awareness doesn’t directly benefit the wizard unless it is able to timely communicate the presence of foes to the wizard.

How quickly can a familiar warn its wizard of the oncomming danger? Is that instantaneous, is it as fast as regular speech, or something in between?

1 100 feet divided by 1124 feet/s = 0.08 seconds with the speed of sound. Telepathy doesn’t require air so probably goes with the speed of light resulting in 0.0000001 seconds.

This question is different to How much can you communicate with your familiar in that that question asks what kind of concepts can be conveyed whereas this question asks how fast those concepts can be explained.

Would an Antimagic Field block telepathic communication with a familiar?

Ichabod the Inscrutable has an imp familiar and is exploring a dungeon. He comes across a series of trapped rooms that have Antimagic Fields in them, and he wants to send his familiar to explore them.The Antimagic Fields completely fill each room, but do not extend beyond their walls.

Ichabod is currently standing outside of the first room.

Would an Antimagic Field block telepathic communication with a familiar?

If a druid Wild Shapes and merges with a telepathic sentient item, will the item’s telepathy be suppressed?

Suppose a druid is in possession of a sentient magical item that possesses telepathy. If the druid wild shapes and chooses to merge the item into their form, will the item’s telepathy be suppressed? The rules say, “Equipment that merges with the form has no effect until you leave the form.” Is telepathy an “effect”?

Do monsters with the “Telepathy” language automatically sense creatures in their telepathic radius?

Some monsters possess the special “Telepathy” language.

Telepathy Telepathy is a magical ability that allows a monster to communicate mentally with another creature within a specified range. The contacted creature doesn’t need to share a language with the monster to communicate in this way with it, but it must be able to understand at least one language. A creature without telepathy can receive and respond to telepathic messages but can’t initiate or terminate a telepathic conversation.

A telepathic monster doesn’t need to see a contacted creature and can end the telepathic contact at any time. The contact is broken as soon as the two creatures are no longer within range of each other or if the telepathic monster contacts a different creature within range. A telepathic monster can initiate or terminate a telepathic conversation without using an action, but while the monster is incapacitated, it can’t initiate telepathic contact, and any current contact is terminated. (MM p.9)

Does this ability allow them to sense the position of all creatures within the radius of their telepathy, given that “A telepathic monster doesn’t need to see a contacted creature”?

Can a wizard under the effects of Feign Death issue telepathic commands to their familiar?

A wizard has a summoned familiar within 100 feet that is currently idle and has Feign Death cast on them by another PC. Would the wizard still be able to issue telepathic commands to their familiar?

Specifically, while Feign Death states that they appear dead and are incapacitated and blind, they aren’t listed as being unconscious.

Find Familiar doesn’t state that issuing telepathic commands requires an action (which you can’t do while incapacitated), whereas it does state that seeing through your familiar’s eyes requires an action as does dismissing it.

I was DMing a game where this occurred and I hastily ruled that the wizard was unable to issue commands, but I am second guessing myself after the fact. And knowing my PCs this situation is likely to happen again.

Meenlock telepathic torment on target with 0 HP: Guaranteed 1 hour meenlock?

Consider the meenlock, a fey creature of pure terror described in Volo’s Guide to Monsters (page 170). As GM I am going to have my players encounter these creatures in our next session. They have been stalking the countryside, abducting villagers and turning them into more meenlocks. However, I have found what seems to be an inconsistency between their stats and the prose describing their behaviour.

They ‘reproduce’ by telepathically tormenting an incapacitated victim.

Up to four meenlocks can telepathically torment one incapacitated creature… If the creature is susceptible [not immune to the frightened condition] and remains incapacitated for 1 hour, the creature must make a Wisdom saving throw, taking 10 (3d6) psychic damage on a failed save, or half as much damage on a successful one… The process can be repeated. A humanoid that drops to 0 hit points as a result of this damage instantly transforms into a meenlock.

Meenlocks have two strategies for this according to Volo. One strategy is “to crawl out of their tunnels to torment sleeping prey.” This is not the strategy I have questions about, as a sleeping creature typically has full health. Their other strategy raises some questions.

Meenlocks like to paralyze creatures with their claws, drag them back to their hidden den, beat them unconscious, and telepathically torture them over a period of hours.

To beat someone unconscious requires dropping them to zero hit points. Their paralysis only lasts for one minute, so unconsciousness is the only reliable way that a meenlock can keep someone incapacitated for a whole hour. So meenlocks would frequently torment creatures that are already on 0 HP.

But here we have an issue. The telepathic torment is guaranteed to deal at least 1 point of damage (unless you are resistant to psychic damage, in which case you have a 0.5% chance of avoiding damage if you pass the save). But because the target is already at 0 HP it will invariably take damage and be left at 0 HP by the telepathic torment (if not killed outright), which means that this telepathic torment will invariably take only one hour regardless of saving throws or damage rolls, or so it seems. This is in contradiction to Volo’s description that this torment lasts several hours. It is also means that a captured creature has no capacity to resist this effect despite it notionally offering a Wisdom saving throw.

An alternative interpretation is that it is not possible to ‘drop to 0 hit points’ when you are already at 0 hit points. This appears to be how death ward is interpreted. However, if we take this interpretation, then it becomes impossible for the meenlocks to perform their strategy of beating someone unconscious and then tormenting them. The meenlocks would have to wait for the target to recover hit points before they can successfully torment them, but if the target recovers hit points they stop being incapacitated so cannot be tormented.

What happens when meenlocks use their telepathic torment on a victim they have beaten unconscious?

Does the damage inflicted on the unconscious victim invariably turn them into a meenlock after the first hour? In this case Volo made a mistake when he wrote that the process lasts for “a period of hours”. It also means that the rules for damage and saving throws for telepathic torment are only useful when the meenlocks target a healthy, sleeping victim. From my own reading of the rules this appears to be the most fitting interpretation. I would have liked the process to be longer, for the sake of dramatic tension and chances of resistance and rescue, but I can make do.

Is telepathic torment unable to transform a creature already at 0 hit points? While a strict rules-as-written argument could be made for this, I feel this interpretation is directly contrary to how meenlocks are meant to work.

Is it some other outcome? Maybe I missed something. Maybe there is a plausible and consistent way for meenlocks to beat a creature unconscious and have to spend several hours (rather than just one) tormenting them before the transformation occurs. But without homebrewing the telepathic torment mechanics I can’t see how that could happen.

Learning or preparing a spell over Telepathic Bond?

Just wondering… Would a telepathic bond spell cast on my helper npc (another wizard of equal or greater level; stationed in a magic library) allow them to “stream” my spellbook’s contents to me as if I was reading it when resetting daily spells?

If I keep the spellbook instead, would I be able to have the helper stare at books in order to add new spells to the spellbook?

Can your familiar (via Find Familiar) initiate telepathic communication with you? [duplicate]

The find familiar spell says (emphasis mine):

While your familiar is within 100 feet of you, you can communicate with it telepathically.

So, clearly you can speak to it telepathically, say to issue commands to it. But can it:

  • Reply to your message?
  • Initiate a conversation with you?

As it happens, I’m going to have a pseudodragon familiar (via warlock, Pact of the Chain), which can respond in it’s own way:

Limited Telepathy. The pseudodragon can magically communicate simple ideas, emotions, and images telepathically with any creature within 100 feet of it that can understand a language.

So in my case, it’s more about whether it can reply with words (either because it can speak to me telepathically due to find familiar, or because I’ve “initiated” a telepathic conversation with it, similar to the message cantrip, even though that’s not actually telepathy), or whether it can only reply at all because of its own ability (via “Limited Telepathy“, which obviously won’t be with words, if it turns out that the telepathy via find familiar is one-way only).

I’m hoping to figure out which interpretation is correct by knowing the answer to my above questions about whether any familiar (via find familiar) can telepathically communicate with the caster at all.