# Pre Mortem

> Find what will kill a plan before it's committed to — by assuming it already failed and working backwards to the causes. Based on Gary Klein's pre-mortem technique. Unlike generic "what are the risks?" brainstorming, this skill imagines a specific, vivid failure six months out, reasons back to the most likely causes, ranks them by likelihood × impact, and prescribes the single highest-leverage fi…

- **Type:** Skill
- **Install:** `agentstack add skill-3243dwon-clear-eye-pre-mortem`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [3243dwon](https://agentstack.voostack.com/s/3243dwon)
- **Installs:** 0
- **Category:** [AI & ML](https://agentstack.voostack.com/c/ai-and-ml)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [3243dwon](https://github.com/3243dwon)
- **Source:** https://github.com/3243dwon/clear-eye/tree/main/pre-mortem

## Install

```sh
agentstack add skill-3243dwon-clear-eye-pre-mortem
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Pre-Mortem

A post-mortem asks why something died. A **pre-mortem** runs it *before* you commit: imagine the plan has already failed, then reason backward to why. Prospective hindsight makes people name risks they'd otherwise stay politely quiet about.

## Core principle

> Don't ask "what are the risks?" (vague, easy to wave away).
> Say "It's six months later and this failed badly. What happened?" — then explain the failure as if it already occurred.

## The process

1. **Fix the plan and a horizon.** What's being attempted, and by when do we judge it?
2. **Declare failure.** Vividly: "It's [horizon]. The plan failed. It was a disaster." Sit in that world.
3. **Generate causes.** List the reasons it failed — concrete, specific, in past tense ("the migration corrupted prod data because the dry-run skipped foreign keys"), not abstractions ("poor execution").
4. **Rank by likelihood × impact.** Score each cause on both; sort. The top of that list is where attention belongs.
5. **Prescribe the one fix that matters most.** For the top risks, the single highest-leverage mitigation — and a cheap early-warning signal that tells you it's materializing.

## Output format

1. **The failure scenario** — 2–3 vivid sentences, past tense.
2. **Ranked failure causes** — a table or list: cause · likelihood (H/M/L) · impact (H/M/L). Lead with high×high.
3. **The one fix** — the single most leverage-rich mitigation. If you do nothing else, do this.
4. **Early-warning signals** — the cheap canaries that tell you a top risk is happening while there's still time.
5. *(Optional)* **Kill criteria** — the line that, if crossed, means stop.

## Worked example

**Plan:** Ship a payments rewrite to all users in 6 weeks.

> **Failure scenario:** It's week 7. The cutover dropped ~2% of transactions for three days before anyone noticed; finance can't reconcile, support is on fire, and we've rolled back to a codebase nobody remembers.
>
> **Ranked causes:**
> | Cause | Likelihood | Impact |
> |---|---|---|
> | No transaction-level reconciliation between old/new during rollout | High | High |
> | Big-bang cutover instead of % rollout | High | High |
> | Edge-case currencies untested (only USD in staging) | Med | High |
> | On-call didn't know the new system | Med | Med |
>
> **The one fix:** Don't big-bang it. Run new + old in **shadow mode** reconciling every transaction, then ramp 1% → 100%. This alone defuses the top two risks.
>
> **Early-warning signals:** Any non-zero reconciliation mismatch in shadow mode; a rise in payment-retry rate; support tickets mentioning "charged twice".
>
> **Kill criteria:** >0.1% unreconciled at any rollout step → halt and roll back the increment.

## Anti-patterns to avoid

- Listing vague risks ("scope creep", "bad communication") instead of specific failure mechanisms
- Skipping the ranking — a flat list of 20 risks helps no one
- Naming risks but prescribing no concrete fix or signal
- Politeness: the technique only works if you let it actually fail in the story

---

> Part of the [clear-eye](https://github.com/3243dwon/clear-eye) pack — Claude skills for seeing what others miss.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [3243dwon](https://github.com/3243dwon)
- **Source:** [3243dwon/clear-eye](https://github.com/3243dwon/clear-eye)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-3243dwon-clear-eye-pre-mortem
- Seller: https://agentstack.voostack.com/s/3243dwon
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.