# thinking-pre-mortem

Assumes a plan or launch has already failed, traces concrete causes backward, and turns them into explicit gates, owners, and verification checkpoints.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 660 installs · ★ 1674
- Author: tjboudreaux
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/tjboudreaux/cc-thinking-skills/tree/HEAD/skills/thinking-pre-mortem/SKILL.md
- Updated: 2026-08-07
- HTML: https://affpapa.org/en/nevibecode/skills/thinking-pre-mortem

## What it does

The skill applies prospective hindsight rather than asking open-ended questions about what might fail. It sets the scenario strictly in the past tense with a specific date and failure mode, such as data loss, rollback, or missed SLAs. The agent then sweeps five failure areas: technical components, processes, hidden assumptions, external dependencies, and people.

Generic risks like scope creep get dropped immediately. The process scores issues by likelihood and impact to isolate the top 3–5 failure paths. For each path, the model extracts necessary conditions that enabled the failure, inverts them into mandatory prevention rules, and assigns an owner alongside a verification checkpoint.

A pre-mortem run that leaves the project plan untouched is an incomplete ritual. This routine is built strictly for pre-execution commits; running it during active incident firefighting or on small, cheap changes just wastes time.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add tjboudreaux/cc-thinking-skills --skill thinking-pre-mortem -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/thinking-pre-mortem/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/thinking-pre-mortem/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add tjboudreaux/cc-thinking-skills --skill thinking-pre-mortem -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/thinking-pre-mortem/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add tjboudreaux/cc-thinking-skills --skill thinking-pre-mortem -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/thinking-pre-mortem/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install tjboudreaux/cc-thinking-skills thinking-pre-mortem
```

2. **Manually: put the files in place**
- File: `.github/skills/thinking-pre-mortem/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add tjboudreaux/cc-thinking-skills --skill thinking-pre-mortem -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/tjboudreaux/cc-thinking-skills --path skills/thinking-pre-mortem
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/thinking-pre-mortem/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add tjboudreaux/cc-thinking-skills --skill thinking-pre-mortem -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/tjboudreaux/cc-thinking-skills/tree/HEAD/skills/thinking-pre-mortem/SKILL.md

## When to use it
- identify critical launch risks before writing code
- filter out generic failure warnings in favor of 3–5 concrete paths
- invert failure conditions into enforceable gate rules
- assign clear checkpoints and owners to prevent project derailment
- update technical roadmaps with explicit fallback spikes

## Example prompts
- Run a pre-mortem on our database migration plan scheduled for next Tuesday
- Apply thinking-pre-mortem to the new authentication rollout plan
- Assume the launch failed due to an SLA breach and update our plan with prevention gates

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: c3e1710e5eb8ee6d.

BEGIN THIRD-PARTY FILE c3e1710e5eb8ee6d
```text
---
name: thinking-pre-mortem
description: Before committing to a plan or launch, assume it already failed and reason backward through concrete causes — convert failure paths into mitigations, gates, and stop checks.
disable-model-invocation: true
---

# Pre-Mortem Analysis

**Core rule:** Prospective hindsight beats "what could go wrong?" Assume the plan has already failed (past tense), generate concrete failure paths, reverse them into prevention requirements, and bind each top path to a verifiable plan change.

## When to Use

- Before kickoff, major technical commitment, high-risk sprint work, launch, or release.
- After a plan looks solid but before execution, especially when optimism or overconfidence is likely.
- When a decision is costly to reverse and risks are still implicit rather than enforced.

## When NOT to Use

- Work is small, local, and cheaply reversible — skip the ceremony.
- You are mid-incident under time pressure — act now (OODA / scientific method); pre-mortem is pre-execution.
- You would only emit generic risks ("scope creep", "requirements unclear") that do not bind to this plan.
- Risks are already enforced by live gates (CI, canary, rollback, alerts) with no residual unlisted path.
- A mature risk register already covers the same specific failure paths with owners and checks.

## Procedure

1. **Set the failure frame in past tense:** "It is [post-deadline date]. The plan failed: [rollback / data loss / no adoption / SLA breach]." Explaining a happened failure is required; predicting one is not enough.
2. **Generate failure reasons before filtering:** sweep technical, process, assumptions, dependencies/external, and people. Force a second pass: "What did the plan most need to be true that was not?" Collect breadth first (aim for many distinct reasons); do not rank mid-sweep.
3. **Prioritize:** group by theme; score likelihood × impact; keep the top 3–5 concrete risks (drop generics that do not bind).
4. **Failure-first reverse analysis (absorbed reverse path):** for each top risk, (a) restate the failed outcome in past tense, (b) list **necessary/enabling conditions** that had to be true for that failure, (c) **invert** each condition into a verifiable prevention requirement (avoid/require rule + check), (d) bind **owner, verification checkpoint, and ship/stage gate**.
5. **Mitigate and update the plan:** for each top risk, attach mitigation steps, spike/contingency if needed, and the reverse-analysis prevention requirements as explicit plan gates. A pre-mortem with no plan change is incomplete.
```
END THIRD-PARTY FILE c3e1710e5eb8ee6d

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First 2577 of 3732 bytes. © tjboudreaux · MIT · https://github.com/tjboudreaux/cc-thinking-skills/tree/HEAD/skills/thinking-pre-mortem/SKILL.md

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