Brainstorm

Reply in the project conversation language (CLAUDE.md → Language); code, identifiers, paths and commit messages stay in English.

Reference: stack-reference/index.md (what the studio builds and with which versions); the brief feeds the product-spec.md / game-concept.md templates that follow. This skill delegates nothing: the conversation, the framing and the brief are the director's own work, so Task is not among its tools. In the commands below, <hooks> is .claude/hooks/ in copy mode and ${CLAUDE_PLUGIN_ROOT}/hooks/ in plugin mode.

Phase 1: Conversation

Clarify via AskUserQuestion, one question at a time; with no argument, the first question is the idea itself.

1. For whom.
2. Which pain or desire.
3. What already exists on the market: allow WebSearch for 3–5 comparable products. When WebSearch is unavailable, say so in one line, ask the user for the comparables they know, and carry them into the brief marked unverified (named by the user) — never a comparable invented from memory.
4. Constraints: time, budget, stack, platforms.
5. For games: genre, session, the player's "verb" (the most frequent action).

Phase 2: Framing

Generate 3 positioning variants (narrow/medium/wide scope) with cost and risk; for games — 3 core-loop variants (MDA: mechanics → dynamics → aesthetics). Propose success metrics and "what must be true" for the idea to work (hypotheses to validate).

Phase 3: Concept brief

1. Draft docs/specs/concept-brief.md from .claude/docs/templates/concept-brief.md: the eight sections in the template's order (essence, personas, pain, differentiation, MVP candidate, hypotheses with a validation table, risks, next step). /product-spec Phase 1 reads this file as its input, so a brief that invents its own shape costs the next skill the facts it came for.
2. A section with nothing behind it is written as n/a — reason, never dropped.
3. Show the draft in the chat, then "May I write docs/specs/concept-brief.md?" — one AskUserQuestion: write (Recommended) · show the draft/diff first · not now. After the "write" answer: touch .claude/.write-consent (rule 7 — the consent-guard hook checks the marker).

Phase 4: Commit (documents lane)

Right after the write, one commit gate (rule 7 (4), .claude/docs/git-workflow.md § Documents): one AskUserQuestion offering docs: concept brief, staging exactly the written files — docs/specs/concept-brief.md. Record the gate before asking — <hooks>session-state.sh set Gate "/brainstorm Phase 4: commit?" — and clear it after the answer (<hooks>session-state.sh set Gate "—").

• On the default branch when no story work is in progress.
• When HEAD is a story branch, name it and offer: switch to the default branch and commit there (Recommended — a pipeline-wide document) · commit here (the document belongs to this story) · leave uncommitted.
• Code, configs, workflows and scripts never ride the docs: commit.

Nothing is committed without the answer.

Verdict: COMPLETE. Next step — one AskUserQuestion: /setup-stack (Recommended) · /product-spec or /game-concept directly · revise the brief.