When a scene needs more than one character
An ensemble stage puts two to five story cards in one room. A director chooses who speaks, and you can still nudge or narrate.
A cast, not a pile of solo chats
Some moments only work if someone else is in the room: a rivalry, a dinner, a secret two people are hiding from a third. Plotty's ensemble templates seat those characters together. Each member is a story card with a name, a look, and a relation to the others.
Replies stay short enough to pass the turn. The point of the stage is that the next person can answer, including you.
What you can do on a turn
Speak, continue the scene, nudge someone who has gone quiet, or write a narration beat. Narration moves the room: time, weather, a door. It does not decide what a character feels.
Relations such as friend, rival, or a custom note are part of the stage directions. They keep the chemistry from resetting every turn.
Use a solo storyline when the room should be empty
A confession, a quiet walk, a first meeting: those belong on a single storyline. Move to an ensemble when the plot needs witnesses, interruptions, or a choice that more than one character will react to.