Without warning, a wizard casts telepathy targeting a friend who is on a different continent.

You create a telepathic link between yourself and a willing creature with which you are familiar.

How is it decided whether the target is willing? Does the wizard get 6 seconds to quickly introduce herself? Does the target "feel" a "friend request/phone call" and envision the caster in their head and then decide whether to let them in/answer?

I wondered if the spell assumes the target is willing until the target decides otherwise, but there is no option for the target to end the spell.

  • 5
    \$\begingroup\$ I reopened because what defines "a willing creature" and when that definition is actually used are two different things. The dupe target asked the former, this question asks the latter. Furthermore, this question is about the specifics of the telepathy spell and what the target knows when willingness is determined, which is not part of the willingness definition question \$\endgroup\$ Commented Mar 18, 2022 at 2:07
  • \$\begingroup\$ You can only cast it if you are a familiar, and only on your master. Read the quoted text carefully. \$\endgroup\$
    – User 23415
    Commented May 15 at 1:04

3 Answers 3


On further review, later in the spell description it says (emphasis added):

Until the spell ends, you and the target can instantaneously share words, images, sounds, and other sensory messages with one another through the link, and the target recognizes you as the creature it is communicating with.

I see two reasons for that text:

  1. To handle the corner case of multiple telepathy effects (you know who is who among the many voices in your head); and
  2. The word "willing" is in error earlier in the spell and this sentence is indicating that the target knows who is "calling them".

Note that the sharing of thoughts is optional, so there is no risk for unwilling recipients except maybe distracting images?

I agree that RAW, you need to arrange things ahead of time (as per above), but I'm thinking that RAI you make the connection and they know who you are and can choose whether to share their thoughts.


Short answer, you will need to establish an agreement ahead of time. As the check occurs before the connection is ever established.

This is apparently not a spell used for cold calling.

As explained by @Fie (emphasis theirs)

according to the spell targetting rules in XGE (pp. 85–6), the validity of the target (i.e. whether the creature is willing) must be determined before the spell has any effect (including the target recognising you as the creature it is communicating with).

Meaning that though you are familiar with the target, they must be willing to receive your message before they receive it. A short conversation among friends can be had, "Hey, is it ok if I use telepathy to communicate with you in the future?" to establish that willingness in some regard ahead of time.

If the target for some reason becomes unwilling, the spell will fail without contact ever being established and the target not realizing you attempted to reach them. Perhaps they are busy at the moment, but that doesn't stop them from later being willing once more.

The Willingness check will occur before connection is made on casting the spell.

Alternatively, there may be a discussion on the hypothetical,

  • "if A somehow knew that it was B calling, would they accept the call?" willingness being applied that way, as they are willing in this case.

But it is unclear if the question instead is,

  • "are they willing to accept an unknown call before knowing who sent the request?" which might not be the same willingness.

Could be stated more clearly in either case.

Curious though, the duration is 24 hours without an off switch other than moving to another plane of existence. Once the spell succeeds, the willingness of the creature to continue the link is seemingly no longer considered.

  • 2
    \$\begingroup\$ Note that the emboldened clause is conditional on the spell being in effect: according to the spell targetting rules in XGE (pp. 85–6), the validity of the target (i.e. whether the creature is willing) must be determined before the spell has any effect (including the target recognising you as the creature it is communicating with). \$\endgroup\$
    – Fie
    Commented Mar 18, 2022 at 14:36

The rules don't specify the exact mechanism, so the GM will need to adjudicate.

If the target of the spell is a PC, the GM will need to give the player enough information to decide if the PC is willing.

If the target of the spell is an NPC, the GM will need to decide for the NPC.

The GM may want to establish house rules for exactly how it works, but the need for those rules is going to vary tremendously from table to table.

In many cases, the adjudication should be pretty easy.

Let's assume the target is a PC:

GM: You get a strange feeling. Your friend, Wendy the Wizard, is trying to establish a telepathic link with you. Are you willing? Player: I...how do I know it's Wendy? GM: You just know. Player: How do I know? GM: It's magic, but it's sort of like seeing someone's face or hearing their voice, you recognize them.

At this point, the player decides whether to accept the connection or not, or maybe they ask more questions.

A given table may need to have further discussion, or may not.


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