karpathy-llm-simulator

Skill 3: LLM as Simulator（LLM模拟器思维）

Source: https://x.com/karpathy/status/2037921699824607591 | https://x.com/karpathy/status/2049907410303865030 "Drafted a blog post → LLM argue the opposite" — 31k likes

Core Principle

Don't ask what the LLM thinks. Ask it to simulate what a diverse group of experts would argue.

LLMs are trained to please. A direct question gets a sycophantic answer. A simulation request gets a distribution of real perspectives — including the uncomfortable ones.

Karpathy's method: write a draft → ask LLM to argue the strongest possible opposite position → synthesize a better view.

The 4 Simulator Modes

Mode 1: Expert Debate Panel

Best for: technical decisions, architecture choices, research directions

Simulate a structured debate between these 3 expert personas on [TOPIC/DECISION]:

Expert A: [most optimistic / pro position]
Expert B: [most skeptical / con position]  
Expert C: [pragmatic outsider / unexpected angle]

For each expert:
- State their core argument in 3 sentences
- Cite 2 specific examples or data points they'd use
- Identify what they'd say is the FATAL FLAW in the opposing view

After the debate, synthesize: what's the strongest hybrid position that survives all three critiques?

Topic: [YOUR_TOPIC]
My current position: [YOUR_DRAFT_VIEW]

Mode 2: Steel Man the Opposite

Best for: before publishing, before committing to a decision

I'm about to [ACTION / PUBLISH / DECIDE]:

[YOUR PLAN OR DRAFT]

Steel man the strongest possible argument AGAINST this. Be merciless.
Don't hedge. Don't say "while this has merit...". 
Argue as if you genuinely believe the opposite and need to convince a skeptical expert.

Then: what would it take to make my original position survive this attack?

Mode 3: Pre-Mortem Simulation

Best for: project planning, product launches, major decisions

Imagine it's [DATE 6 MONTHS FROM NOW] and [YOUR PROJECT/PLAN] has failed completely.

Simulate 3 different failure modes — each from a different root cause:
1. Technical failure: what went wrong in the implementation?
2. Strategic failure: what assumption proved wrong?
3. Execution failure: what human/process error occurred?

For each: describe the specific sequence of events that led to failure.

Then: what early warning signals would have been visible by [DATE 1 MONTH FROM NOW]?