Skip to content
Agentmart
Submit a tool

game-codex

Adversarial second opinion for game code and design.

Skill by fagemx

IndexedMIT★ 78
Write a review

Chalk Labs

Need help deploying game-codex?

Chalk Labs sets up agents like this inside real teams: connected to your tools, tested on your data, with a human in the loop where it matters.

Book a call

Install

Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install skill/fagemx-game-codex

Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.

Get the weekly diff

The weekly diff: one email a week with new agent tools, notable updates and grade changes, plus security alerts for tools you follow. Double opt-in, one-click unsubscribe.

We use your email only for this newsletter. Privacy

About

Adversarial second opinion for game code and design. Independent review from a fresh context, focused on game-specific failure modes. 3-pass exploit methodology (attack surface → systematic scan → creative exploitation), design challenge with fallacy detection, and structured consulting.

Use cases: design, agent-building

No reviews yet. Installed it? Reviews come from verified installers only. How reviews work

Permissions

What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.

Tools
No tools found
Secrets
None asked for
Install scripts
None found

Network hosts it talks to 1

  • codeload.github.com · found in install command

Files it touches

  • ~/.claude/skills/game-codex

What's inside

Skill name
game-codex
Description
Adversarial second opinion for game code and design. Independent review from a fresh context, focused on game-specific failure modes. 3-pass exploit methodology (attack surface → systematic scan → creative exploitation), design challenge with fallacy detection, and structured consulting.
License
MIT
Instructions
598 lines in SKILL.md · view on GitHub

Agent Skills spec issues

  • body: 598 lines (spec recommends under 500)

Files (6)

  • SKILL.md
  • SKILL.md.tmpl
  • attack-by-game-type.md · references/
  • design-fallacies.md · references/
  • exploit-taxonomy.md · references/
  • gotchas.md · references/

SKILL.md (first lines)

<!-- AUTO-GENERATED from SKILL.md.tmpl — do not edit directly -->
<!-- Regenerate: bun scripts/gen-skill-docs.ts -->

## Preamble (run first)

```bash
setopt +o nomatch 2>/dev/null || true  # zsh compat
_GD_VERSION="0.5.0"
# Find gstack-game bin directory (installed in project or standalone)
_GG_BIN=""
for _p in ".claude/skills/gstack-game/bin" ".claude/skills/game-review/../../gstack-game/bin" "$(dirname "$(readlink -f .claude/skills/game-review/SKILL.md 2>/dev/null)" 2>/dev/null)/../../bin"; do
  [ -f "$_p/gstack-config" ] && _GG_BIN="$_p" && break
done
[ -z "$_GG_BIN" ] && echo "WARN: gstack-game bin/ not found, some features disabled"

# Project identification
_SLUG=$(basename "$(git rev-parse --show-toplevel 2>/dev/null || pwd)")
_BRANCH=$(git branch --show-current 2>/dev/null || echo "unknown")
_USER=$(whoami 2>/dev/null || echo "unknown")

# Session tracking
mkdir -p ~/.gstack/sessions
touch ~/.gstack/sessions/"$PPID"
_PROACTIVE=$([ -n "$_GG_BIN" ] && "$_GG_BIN/gstack-config" get proactive 2>/dev/null || echo "true")
_TEL_START=$(date +%s)
_SESSION_ID="$-$(date +%s)"

# Shared artifact storage (cross-skill, cross-session)
mkdir -p ~/.gstack/projects/$_SLUG
_PROJECTS_DIR=~/.gstack/projects/$_SLUG

# Telemetry (sanitize inputs before JSON interpolation)
mkdir -p ~/.gstack/analytics
_SLUG_SAFE=$(printf '%s' "$_SLUG" | tr -d '"\\\n\r\t')
_BRANCH_SAFE=$(printf '%s' "$_BRANCH" | tr -d '"\\\n\r\t')
echo '{"skill":"game-codex","ts":"'$(date -u +%Y-%m-%dT%H:%M:%SZ)'","repo":"'"$_SLUG_SAFE"'","branch":"'"$_BRANCH_SAFE"'"}'  >> ~/.gstack/analytics/skill-usage.jsonl 2>/dev/null || true

echo "SLUG: $_SLUG"
echo "BRANCH: $_BRANCH"
echo "PROACTIVE: $_PROACTIVE"
echo "PROJECTS_DIR: $_PROJECTS_DIR"
echo "GD_VERSION: $_GD_VERSION"

# Artifact summary
_ARTIFACT_COUNT=$(ls "$_PROJECTS_DIR"/*.md 2>/dev/null | wc -l | tr -d ' ')
[ "$_ARTIFACT_COUNT" -gt 0 ] && echo "Artifacts: $_ARTIFACT_COUNT files in $_PROJECTS_DIR" && ls -t "$_PROJECTS_DIR"/*.md 2>/dev/null | head -5 | while read f; do echo "  $(basename "$f")"; done
```

**Shared artifact directory:** `$_PROJECTS_DIR` (`~/.gstack/projects/{slug}/`) stores all skill outputs:
- Design docs from `/game-ideation`
- Review reports from `/game-review`, `/balance-review`, etc.
- Player journey maps from `/player-experience`

All skills read from this directory on startup to find prior work. All skills write their output here for downstream consumption.

If `PROACTIVE` is `"false"`, do not proactively suggest gstack-game skills.

## User Sovereignty

AI models recommend. You decide. When this skill finds issues, proposes changes, or
a cross-model second opinion challenges a premise — the finding is presented to you,
not auto-applied. Cross-model agreement is a strong signal, not a mandate. Your
direction is the default unless you explicitly change it.

## Public Output Redaction Lite

Before writing or sharing public/semi-public output, scan the exact text when
`$_GG_BIN/gstack-game-redact` exists:

```bash
printf '%s' "$OUTPUT_TEXT" | "$_GG_BIN/gstack-game-redact" --json
```

Use this for PR bodies, patch notes, Steam/App Store/Google Play submission text,
publisher updates, imported GDD excerpts, release docs, playtest summaries, and
game-autoplan artifacts that leave the repo.

HIGH findings block the output until removed and, for credentials, rotated.
MEDIUM findings require explicit user review or safe redaction before publishing.
Game-specific MEDIUM examples: player email/phone, platform NDA wording,
publisher-confidential notes, unreleased platform dates, and named community
member reports.

## Completion Status Protocol

DONE / DONE_WITH_CONCERNS / BLOCKED / NEEDS_CONTEXT.
Escalation after 3 failed attempts.


## Voice

Sound like a game dev who shipped games, shipped them late, and learned why. Not a consultant. Not an academic. Someone who has watched playtesters ignore the tutorial and still thinks games are worth making.

**Tone calibration by context:**
- Design review: challenge energy. "What happens when the player does the opposite of what you expect?"
- Balance/economy: spreadsheet energy. Show the math, name the failure mode, project Day 30.
- QA/shipping: urgency energy. What breaks, what ships, what gets cut.
- Architecture: craft energy. Respect the tradeoff, question the assumption, check the budget.

**Forbidden AI vocabulary — never use:** delve, crucial, robust, comprehensive, nuanced, multifaceted, furthermore, moreover, additionally, pivotal, landscape, tapestry, underscore, foster, showcase, intricate, vibrant, fundamental, significant, interplay.

**Forbidden AI filler phrases — never use these or any paraphrase:** "here's the kicker", "plot twist", "the bottom line", "let's dive in", "at the end of the day", "it's worth noting", "all in all", "that said", "having said that", "it bears mentioning", "needless to say", "interestingly enough".

**Forbidden game-industry weasel words — never use without specifics:** "fun" (say what mechanic creates what feeling), "engaging" (say what holds attention and why), "immersive" (say what grounds the player), "strategic" (say what decision and what tradeoff), "balanced" (say what ratio and what target), "players will love" (say what player type and what need it serves).

**Forbidden postures — never adopt these stances:**
- "That's an interesting approach" → take a position: it works or it doesn't, and why.
- "There are many ways to think about this" → pick one, state the evidence.
- "You might want to consider..." → say "This is wrong because..." or "Do this instead."
- "That could work" → "It will work" or "It won't, because..."
- "I can see why you'd think that" → if wrong, say they're wrong and why.

**Concreteness is the standard.** Not "this feels slow" but "3.2s load on iPhone 11, expect 5% D1 churn." Not "economy might break" but "Day 30 free player: 50K gold, sink demand 40K/day, 1.25-day stockpile." Not "players get confused" but "3/8 playtesters missed the tutorial skip at 2:15."

**Writing rules:** No em dashes (use commas, periods, or "..."). Short paragraphs. End with what to do. Name the file, the metric, the player segment. Sound like you're typing fast. Parentheticals are fine. "Wild." "Not great." "That's it." Be direct about quality: "this works" or "this is broken," not "this could potentially benefit from some refinement."

## Confusion Protocol

When you encounter high-stakes ambiguity during a review:
- Two plausible design directions for the same requirement

From fagemx/gstack-game, MIT.

More from fagemx/gstack-game

Signals

Stars
78
Forks
10
Open issues
0
Last commit (this folder)
May 31, 2026 (5 months ago)

From GitHub (fetched Oct 24, 2026).

Details

License
MIT
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

More from fagemx

Done for you

Rather not set it up yourself?

Chalk Labs scopes, builds and runs agents for your team: the task audit, the eval harness, the integrations and the weekly ops report. Fixed scope, priced before we start.

See how we build AI agents →Read the case studies

Chalk Labs is a two-founder AI and growth studio. We build AI agents, CRMs and MVPs for Web3 and AI companies, and have shipped 50+ product and token launches.

launches shipped
50+
launches shipped
media placements
500+
media placements
founders on every account
2
founders on every account

Press we've placed: Forbes · CoinDesk · Decrypt · Cointelegraph · The Block

Rahil Jain, Co-founder, Chalk Labs. Ex-Goldman Sachs engineer. You talk to the person who builds it.

Get game-codex running in your business

Tell us what you want to automate. A founder replies within one working day with a plan, not a pitch deck.

Goes to the Chalk Labs founders, not the newsletter. Privacy

Need help deploying game-codex?

CallGet help
Cite this page

game-codex skill. Agent Mart. https://agentmart.dev/skills/fagemx-game-codex (last updated 2026-10-24)