game-postmortem

game-postmortem is a skill for Claude Code from AlterLab-IEU/AlterLab_GameForge. It costs 87 tokens per session (4,078 once invoked), scanned A, original, MIT.

A structured review of a completed project or major milestone to record what worked, what failed, and what the team learned. It can use development history and existing project notes.

In plain words
What is it for?
Analyzing milestones, reviewing project history, documenting successes and failures, and producing practical lessons for future work.
Why use it?
It turns scattered memories into reusable lessons, helping teams recognize patterns and avoid repeating the same mistakes.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: mentions CLAUDE.md; names the AskUserQuestion tool; mentions Claude Code.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the gameforge plugin — 41 skills, 11 agents, 7 hooks shipped together

Good fit Analyzing milestones, reviewing project history, documenting successes and failures, and producing practical lessons for future work.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add AlterLab-IEU/AlterLab_GameForge
Claude Code
/plugin install gameforge

Made for: Claude Code.

Or install gameforge, the plugin that ships this one along with the rest of its 41 skills, 11 agents, 7 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for game-postmortem

README.md
[![agentmods](https://agentmods.dev/badge/skills/alterlab-ieu/alterlab_gameforge/game-postmortem/github.svg)](https://agentmods.dev/skills/alterlab-ieu/alterlab_gameforge/game-postmortem)
Your own site
<a href="https://agentmods.dev/skills/alterlab-ieu/alterlab_gameforge/game-postmortem"><img src="https://agentmods.dev/badge/skills/alterlab-ieu/alterlab_gameforge/game-postmortem/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for game-postmortem

Your own site · 80×15
<a href="https://agentmods.dev/skills/alterlab-ieu/alterlab_gameforge/game-postmortem"><img src="https://agentmods.dev/badge/skills/alterlab-ieu/alterlab_gameforge/game-postmortem.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 87 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,078 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00087 $0.04078
Opus 5.5 $0.00035 $0.01631
Sonnet 5.5 $0.00017 $0.00816
Haiku 4.5 $0.00009 $0.00408

Measured today against content hash f586b7186178, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

game-postmortem 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 today.

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.

skills/workflows/game-postmortem/SKILL.md · 344 lines

How it starts

The opening of the file, as written. The whole thing — 344 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AlterLab GameForge -- Project Post-Mortem

Every shipped game has a story behind it that is worth more to the next project than the game itself. The post-mortem is where that story is extracted, structured and turned into reusable knowledge. Without one, the team repeats the same mistakes on the next project, not because it is incompetent but because memory is selective and unstructured reflection drifts toward narratives instead of patterns. The GDC Vault and decades of Game Developer magazine postmortems exist because studios learned this the hard way.

A good post-mortem is not a blame session and not a victory lap. It is a structured data extraction: facts first, then reflection, then patterns, then a small number of lessons that each change something concrete.

Projects built with coding agents add a question earlier post-mortems never had to answer: what did the agents actually contribute, and what did they cost? This workflow answers it per milestone, with numbers, so the next project can decide where agents belong.

Relationship to game-retrospective

game-retrospective handles sprints and milestones: short cycles, immediate actions for the next sprint. The post-mortem covers a whole project or a major phase and looks for systemic patterns across those cycles. It ingests every retro it can find.

  • "What should we do differently next sprint?" -> /gameforge:game-retrospective
  • "What should we do differently next project (or next phase)?" -> this skill

When to Use / When Not To

Use after a launch, a cancellation, a major milestone (vertical slice, alpha, beta, 1.0), before starting a new project (to retrieve and apply the last post-mortem), or when a new team member asks "what went wrong last time?"

Instead of this skill... Use
A single sprint or milestone retro /gameforge:game-retrospective
Reviewing the design document /gameforge:game-design-review
Live-game metrics and KPIs after launch /gameforge:game-analytics-setup
Starting the next project with these lessons /gameforge:game-start

Read the full file on GitHub · 344 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. today Changed · -41 lines · -20 tokens per session f586b7186178
  2. 2mo ago First seen · 385 lines · 107 tokens per session scan A d78baaac1b5f

Subscribe to this mod's changes

game-postmortem is a skill published in the GitHub repository AlterLab-IEU/AlterLab_GameForge (52 stars, last pushed yesterday), licensed MIT. It adds 87 tokens to every session and 4,078 once invoked, about $0.0003 per session on Opus 5.5. 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.

Related

game-postmortem compared with skills from other repositories

game-postmortem next to 6 skills from other repositories
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