The cantrip Message:
You point your finger towards a creature within range and whisper a message. The Target (and only the target) hears the message and can reply in a whisper that only you can hear.
Does this qualify as speaking to someone? Are there specific rules somewhere that state what qualifies as "speaking?"
I'm not sure if there are other abilities in other classes but College of Whisper Bard has an ability, Words of Terror, that in part reads:
If you speak to a humanoid alone for at least 1 minute, you can attempt to seed paranoia in its mind.
If the Message cantrip being whispered is considered speaking then it should be able to trigger Words Of Terror.
I was planning on posting this as a separate question but seeing the answers I was receiving and comments on them when this was solely about Message it felt like it could be made as one question.
At 3rd level, you learn to infuse innocent-seeming words with an insidious magic that can inspire terror. If you speak to a humanoid alone for at least 1 minute, you can attempt to seed paranoia in its mind. At the end of the conversation, the target must succeed on a Wisdom saving throw against your spell save DC or be frightened of you or another creature of your choice. The target is frightened in this way for 1 hour, until it is attacked or damaged, or until it witnesses its allies being attacked or damaged. If the target succeeds on its saving throw, the target has no hint that you tried to frighten it. Once you use this feature, you can’t use it again until you finish a short or long rest.
What in fact constitutes "speak to a humanoid alone?" Here are some scenarios I can think of that may help you consider possibilities before hastily answering:
There are two guards 30 ft away from one another in front of a gate. I walk up specifically to the guard on the left and ask my comrades to distract the one on the right with their own conversation. Would this qualify as "speaking alone?"
If we agree that Message qualifies as speaking, and only the mark can hear me and only I can hear the mark's reply would this qualify as "speaking alone?
If a Rogue friend is lurking in the shadows to protect me if things go south but the mark has no idea would this qualify as "speaking alone?"
If I stumble upon a barracks and two guards are sleeping in different beds and I Message only one of them would that qualify as "speaking alone?"
If I multiclass into Warlock and acquire Dark Delirium would its use qualify as "speaking alone?"
If I become invisible by potion or spell and talk to my Mark when others cannot hear us would that qualify as "speaking alone?"