Two sections: I — what each host move looks like in the room, plus the two "hands" (host @-mentions and host reactions); II — the card (the proposed name for the scenario object; siblings: a running instance is a session · 场, the shelf is the deck · 卡库): browsing, casting, the session strip, the receipt. Concept mockups in the room2 aesthetic — not pixel-true to the live app; the Style Guide governs the shipped look. The design constraint carried throughout: passive idioms, learned by seeing — no user-facing syntax anywhere, and exactly one interactive object class: a thing the host handed you, waiting for your tap. Status: concept · 2026-07-20.
① the board — a pin, not a message
Updates in place — never spams the stream. The pin sits under the topbar, collapsible; late joiners see current state instantly. Content grammar is constrained (text · tables · mermaid), so the board stays a whiteboard, not an iframe.
② the note — conceal must be visible
The seal is shown, the content is not. Trust needs the concealment to be visible — a timestamped capsule in the stream says something was committed here. Tapping it explains the envelope; nobody (including the humans' side of the model's output) sees inside.
③ the envelope — the reveal moment
The product moment. Same card in every scenario — the GM's word, the interviewer's rubric, the coach's read. The metadata line is the feature: committed before play, server-witnessed, unchanged. If one idiom gets brand-level polish, it's this.
④ the aside — a bubble only you get
Dashed border + a standing label — unmistakably different from a public bubble, and it never renders for anyone else (fail-closed routing on the anchored id). Secret from other humans, never from the model — which is exactly right for a coach.
⑤ the go-around — everyone in, then one turn
You type normally — the mode is ambient. The host opened the collect, so your message seals itself; the roster card shows who's in and who's outstanding without the host saying a word. The composer dock announces the mode before you type — no surprise seals. Release drains everything into one panel turn. Sealed lines reach nobody's replay — not even the model's — until reveal.
⑥ the follow-up — the host opens a turn
A turn with no human line — the capsule names why it fired (the agreed follow-up), so it reads as punctuality, not surveillance. Consented and rate-capped; rides the notification rail + push when you're away. Also the phase bell: "还剩 5 分钟."
⑦ server truth · the host's roll
Distinct chrome is the whole point. Host-owned randomness — draws, shuffles, seating — renders as a bordered system card with a provenance line, never as anything a persona "said." The host requests it in its output block; the server answers instantly. Nobody types a command.
⑧ server truth · the collect-roll
The gate × the die — simultaneity without chatter. The host hands everyone a die; each player taps their own row; the host speaks once, at completion. Open by default — 乙 can see they need a 15, the best drama in dice; a sealed variant flips together (the 抽签 experience). Ties re-roll automatically. The tap decides when, the server decides what — and note the composer dock: your pending action, fixed where the stream can't scroll it away.
⑨ the hands · host @-mentions
A real chip, not plain text — the host emits the anchored id (@{u:N}), the client renders the same mention chip humans already know, and the mention can ride the notification rail ("it's your turn"). Fail-soft: a malformed token renders as plain text. This is the public proving ground for the aside's routing.
⑩ the hands · host reactions, attributed
Attribution is the feature. Tap the badge → who reacted what, host included — required the moment reactions become precise vocabulary (votes, acks). And the reaction is the quiet half of a turn: mid-collect, the host acknowledges with a 👍 instead of a bubble. Symmetrically, reactions now reach the panel — the host sees the channel it uses.
⑪ the deck — browsing cards
A board-game box lid, not a settings screen. Two-second read: title → seats → duration. The seat row leads (coral dot = persona seat, outlined = human seat); the move chips (板·笔·悄·圈·钟·骰) teach the six moves passively; the byline is the UGC slot waiting. One chassis for every register — serious and playful differ by category chip, never by layout.
⑫ the casting — filling the seats
Persona × card, made tangible. Persona seats declare their requirement — 任意角色 takes anyone (Asimov hosting trivia is charm), 专职 seats want a specialist. Human seats fill from the room or by invite; the card won't start below its minimum. Casting is the whole setup — no settings beyond who sits where.
⑬ the session — a strip, not a takeover
The room stays a room. A running card is a slim strip — card name, round, who hosts — with the board pinned beneath it. Session meta and game state are different objects: the strip belongs to the card, the board belongs to the host. End the session and both fold away; the chat was never hijacked.
⑭ the receipt — a session's afterlife
Sessions leave a record, and a rematch button. The receipt folds the strip and board into one stream card: duration, rounds, the score, every envelope revealed. It's the retention loop in one object — 「再来一场」 re-casts the same card with the same seats in one tap.