# How quickly must a creature respond to the spell Sending?

Sending (PHB.274): (emphasis mine)

Casting Time: 1 action [...]

Duration: 1 round [...]

You send a short Message of twenty-five words or less to a creature with you are familiar. The creature hears the Message in its mind, recognizes you as the sender if it knows you, and can answer in a like manner immediately. The spell enables creatures with Intelligence scores of at least 1 to understand the meaning of your Message. [...]

What constitutes immediately? The spell has a casting time of 1 action, and a duration of 1 round. Does the 1 round make up how long the caster has to send the message after the spell has been cast? Does that same time restriction apply to the receiver? Do both messages have to fit within the same round? Or does the 1 round represent the time it takes for the spell to arrive at the receiver?

• Commented Oct 18, 2020 at 4:02

### "Immediately" probably means "within 1 round."

I have nothing to back this up except a couple of inferences and either a weak absence of evidence argument or Occam's Razor. That said, I still think it's the best we got until another jurist wows the court.

First, how does sending work? It doesn't say that the caster has a round to think of the message, nor does it say that it takes a round to transmit. A person who didn't read the duration could reasonably assume that the message is sent when the spell is cast (if you had a round to think of a message, why would the rules go to the trouble of duplicating the effect of Readying the Cast a Spell action?), and that transmission is Instantaneous. This is the reading that advantages the caster, certainly; if it took 1 round for messages to arrive, PCs would be sending potentially outdated information.

Is there a different reason, then, that sending has such a long duration? I think it's because a creature doesn't act outside their turn (unless specified), while communication is a flourish you may take on your turn (see "Other Activity on Your Turn," PHB p. 190). It seems reasonable that the recipient would answer on their turn.

Now it's quite possible that sending creates a specific rule about communication that overrides the general. But then we're back to not knowing why the spell lasts a round. If "immediately" meant "instantaneously" then sending would be Instantaneous. So I'm inclined to think "1 round" is the limit on "immediately." This does conflict with message not requiring immediate response, but I still think it's the best explanation, and consistent with sending's obvious place as "message but better."

Also, for what it's worth, asking yourself a question and then saying "uh" for 6 seconds does still feel like it is immediate under the "you know it when you see it"/"in human terms" test that Dale M posits in his answer.

## They must respond immediately

The definition of which is “straight away” or “without delay” because that’s what immediately means.

• So if the Receiver does not respond before less than one milllisecond has past since the last word from the caster is received they do not get to respond. Gotcha. Commented Oct 18, 2020 at 5:07
• @JonAristotle why one millisecond rather than one microsecond or one nanosecond? There’s no fixed time on immediately- it means straight away or without delay in human terms Commented Oct 18, 2020 at 5:39
• I know what the word immediately means in human terms, thanks for clarifying, but what about in DND 5e? If a character receives a Sending spell in combat, do they respond on there turn? Are they given no time to think about the response? can they respond as long as it is done before the end of the round? if they can only respond 'immediately,' why does the spell have a duration? Commented Oct 18, 2020 at 6:09
• @JonAristotle There are no secret meanings to English words in the rules. Imagine your boss calling you asking for some information. He says he needs it immediately. Are you going to fail the task if you don't reply within one millisecond?
– Ling
Commented Oct 18, 2020 at 7:32
• @JonAristotle Then your boss is the one using the wrong words. If he means by the end of the day then he should say so. I get the impression you are trying to create a problem where there is none.
– Ling
Commented Oct 18, 2020 at 10:14