Formatting your messages.
Three kinds of lines, one key for your own symbols,
and a bigger page for the long turns.
The three kinds of lines
Chat styles them for you, in your bubbles and in the character's.
Actions
Wrap what your character does in asterisks. It shows in italics.
It reads: sets the cup down and looks up
Dialogue
Wrap spoken words in double quotes. They show in bold, so speech stands apart from everything else.
It reads: “You came back.”
Narration
Anything with no marks is narration: the room, the weather, the hour, what your character notices.
It reads: The rain has not let up since noon.
Prefer plain text? Turn off Stylized text in the settings gear (the small gear above the message box). The marks stay in your messages; only the styling goes.
Lines your character cannot hear
Some writers keep a private channel: inner thoughts, a note to the reader, a whisper meant for someone across the room. Characters should not answer those, and by default they cannot tell them apart from anything else you write.
The Formatting key fixes that once, for every character. Open the settings gear above the message box and write your symbols in plain words. From then on every character reads your messages with that key. It describes your lines, not theirs.
&text& = an action done to the character
(text) = a note to the narrator, not part of the scene
Keep it short. Three or four symbols is plenty, and a symbol you never use only adds noise. The same key is on your Settings page.
Writing the long turns
In the message box, Enter sends and Shift+Enter starts a new line. For a turn that runs to several paragraphs, press the pencil next to the fullscreen button. It opens a bigger page with its own Send button. There, Enter is a new line and Ctrl+Enter (Cmd+Enter on a Mac) sends.
Nothing is lost between the two. Whatever you write in the big page is also in the message box, so Back or Esc keeps your draft exactly where it was.
Small habits that pay off
Write what your character sees, not what the other one feels
Leave their reactions to them. A message that decides how the character feels gives them nothing to play.
End on something they can answer
A question, an action that needs a response, a door left open. Turns that close every thread get flat replies.
Match the register you want back
Characters mirror length and tone. Two lines get two lines; a paragraph with weather and gesture gets one back.
Correct in the story, not around it
If a character gets a detail of the past wrong, say so in your next message. They take the correction and keep going.