What is forecast-premortem?

A forecasting exercise that assumes a prediction has already failed and works backward to find likely causes, blind spots, and rare risks. This method is called a premortem.

Use it to examine a prediction, list concrete failure modes, assess their plausibility, and adjust confidence or uncertainty.

It challenges high confidence before a decision by making overlooked failure scenarios easier to discuss.

forecast-premortem — Skill for Claude Code by The-Utopia-Studio/skills

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.

Any agent

npx skills add The-Utopia-Studio/skills --skill forecast-premortem

Clone the repo

git clone --depth 1 https://github.com/The-Utopia-Studio/skills

Made for: Claude Code.

Or install utopia-investments, the plugin that ships this one along with the rest of its 66 skills.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/the-utopia-studio/skills/forecast-premortem/github.svg)](https://agentmods.dev/skills/the-utopia-studio/skills/forecast-premortem)

Your own site

<a href="https://agentmods.dev/skills/the-utopia-studio/skills/forecast-premortem"><img src="https://agentmods.dev/badge/skills/the-utopia-studio/skills/forecast-premortem/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/the-utopia-studio/skills/forecast-premortem"><img src="https://agentmods.dev/badge/skills/the-utopia-studio/skills/forecast-premortem.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 93 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 3,647 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 91% copy Near-identical to another mod 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.

Model	Per session	Once invoked
Fable 5.1	$0.00093	$0.03647
Opus 5.5	$0.00037	$0.01459
Sonnet 5.5	$0.00019	$0.00729
Haiku 4.5	$0.00009	$0.00365

Measured 2mo ago against content hash de2b86cdcc15, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

forecast-premortem 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 2mo 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

This is a copy

91% identical to forecast-premortem — 37 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

plugins/utopia-investments/skills/forecast-premortem/SKILL.md · 430 lines

How it starts

The opening of the file, as written. The whole thing — 430 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Core Principle: Invert the problem. Instead of "Will this succeed?", ask "It has failed -- why?"

What would you like to do?

Core Workflows

1. Run a Failure Premortem - Assume prediction failed, explain why 2. Run a Success Premortem - For pessimistic predictions (<20%) 3. Dragonfly Eye Perspective - View failure through multiple lenses 4. Identify Tail Risks - Find black swans and unknown unknowns 5. Adjust Confidence Intervals - Quantify the adjustment 6. Learn the Framework - Deep dive into methodology 7. Exit - Return to main forecasting workflow

1. Run a Failure Premortem

Let's stress-test your prediction by imagining it has failed.

Failure Premortem Progress:
- [ ] Step 1: State the prediction and current confidence
- [ ] Step 2: Time travel to failure
- [ ] Step 3: Write the history of failure
- [ ] Step 4: Identify concrete failure modes
- [ ] Step 5: Assess plausibility and adjust

Step 1: State the prediction and current confidence

Tell me:

What are you predicting?
What's your current probability?
What's your confidence interval?

Example: "This startup will reach $10M ARR within 2 years" - Probability: 75%, CI: 60-85%

Step 2: Time travel to failure

The Crystal Ball Exercise:

Jump forward to the resolution date. It is now [resolution date]. The event did NOT happen. This is a certainty. Do not argue with it.

How does it feel? Surprising? Expected? Shocking? This emotional response tells you about your true confidence.

Step 3: Write the history of failure

Backcasting Narrative: Starting from the failure point, work backward in time. Write the story of how we got here.

Read the full file on GitHub · 430 lines

Files

What ships with it

3 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.

2mo ago First seen · 430 lines · 93 tokens per session scan A de2b86cdcc15

Subscribe to this mod's changes

forecast-premortem is a skill published in the GitHub repository The-Utopia-Studio/skills (7 stars, last pushed 11d ago), licensed Apache-2.0. It adds 93 tokens to every session and 3,647 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 91% identical to forecast-premortem, differing in 37 lines, and is treated as a copy.

Analytics and metrics Claude Code Planning agent-skills cursor gtm marketplace skills-sh

forecast-premortem next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
forecast-premortemThe-Utopia-Studio/skills	Skill	7	11d ago	Apache-2.0	A	93	Claude Code
githubkostja94/marketing-skills	Skill	1.1k	2d ago	MIT	A	165	Claude Code, Codex
xml-sitemapkostja94/marketing-skills	Skill	1.1k	2d ago	MIT	A	91	Claude Code, Codex
google-adskostja94/marketing-skills	Skill	1.1k	2d ago	MIT	A	95	Claude Code, Codex
robots-txtkostja94/marketing-skills	Skill	1.1k	2d ago	MIT	A	91	Claude Code, Codex
content-strategykostja94/marketing-skills	Skill	1.1k	2d ago	MIT	A	95	Claude Code, Codex
heading-structurekostja94/marketing-skills	Skill	1.1k	2d ago	MIT	A	57	Claude Code, Codex

forecast-premortem