brainstorm

A guided process for developing a game concept from an initial idea into a structured concept document. It uses interactive questions and studio-style methods to explore genres, themes, scope, player goals, and design pillars.

In plain words
What is it for?
Use it to explore game ideas, compare possible directions, refine a selected concept, rank design pillars, and create or continue a game concept document.
Why use it?
It gives an empty or unfinished idea a clear direction while keeping important creative choices with the user. It can also continue from existing concept documents.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/traftg/opencode-game-studio/brainstorm
Any agent
npx skills add TraftG/opencode-game-studio --skill brainstorm
Clone the repo
git clone --depth 1 https://github.com/TraftG/opencode-game-studio

Made for: Claude Code, Codex.

Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,174 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00036 $0.02174
Opus 5 $0.00018 $0.01087
Sonnet 5 $0.00007 $0.00435
Haiku 4.5 $0.00004 $0.00217

Measured 3d ago against content hash ce2ce575d8de, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

brainstorm scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

2 near-identical copies found in the catalogue:

.opencode/skills/brainstorm/SKILL.md · 211 lines

How it starts

The opening of the file, as written. The whole thing — 211 lines — stays where its author put it; the contents beside it link to each section on GitHub.

When this skill is invoked:

  1. Parse the argument for an optional genre/theme hint (e.g., roguelike, space survival, cozy farming). If open or no argument, start from scratch.

  2. Check for existing concept work:

    • Read design/gdd/game-concept.md if it exists (resume, don't restart)
    • Read design/gdd/game-pillars.md if it exists (build on established pillars)
  3. Run through ideation phases interactively, asking the user questions at each phase. Do NOT generate everything silently — the goal is collaborative exploration where the AI acts as a creative facilitator, not a replacement for the human's vision.

    Use AskUserQuestion at key decision points throughout brainstorming:

    • Constrained taste questions (genre preferences, scope, team size)
    • Concept selection ("Which 2-3 concepts resonate?") after presenting options
    • Direction choices ("Develop further, explore more, or prototype?")
    • Pillar ranking after concepts are refined Write full creative analysis in conversation text first, then use AskUserQuestion to capture the decision with concise labels.

    Professional studio brainstorming principles to follow:

    • Withhold judgment — no idea is bad during exploration
    • Encourage unusual ideas — outside-the-box thinking sparks better concepts
    • Build on each other — "yes, and..." responses, not "but..."
    • Use constraints as creative fuel — limitations often produce the best ideas
    • Time-box each phase — keep momentum, don't over-deliberate early

Phase 1: Creative Discovery

Start by understanding the person, not the game. Ask these questions conversationally (not as a checklist):

Emotional anchors:

  • What's a moment in a game that genuinely moved you, thrilled you, or made you lose track of time? What specifically created that feeling?
  • Is there a fantasy or power trip you've always wanted in a game but never quite found?

Taste profile:

  • What 3 games have you spent the most time with? What kept you coming back?
  • Are there genres you love? Genres you avoid? Why?
  • Do you prefer games that challenge you, relax you, tell you stories, or let you express yourself?

Practical constraints (shape the sandbox before brainstorming):

  • Solo developer or team? What skills are available?
  • Timeline: weeks, months, or years?
  • Any platform constraints? (PC only? Mobile? Console?)
  • First game or experienced developer?

Synthesize the answers into a Creative Brief — a 3-5 sentence summary of the person's emotional goals, taste profile, and constraints. Read the brief back and confirm it captures their intent.


Read the full file on GitHub · 211 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 211 lines · 36 tokens per session scan A ce2ce575d8de

Subscribe to this mod's changes

brainstorm is a skill published in the GitHub repository TraftG/opencode-game-studio (38 stars, last pushed 4mo ago), licensed MIT. It adds 36 tokens to every session and 2,174 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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