first-principles-thinking
First Principles Thinking
Core principle: Strip away assumptions, conventions, and analogies. Reduce everything to the fundamental truths you know to be true, then rebuild from there. Most thinking is by analogy — "we do it this way because that's how it's done." First principles asks: why is it done that way at all?
The Core Process
Step 1: Identify the Current Belief or Solution
State clearly what is currently assumed, accepted, or proposed:
- What is the existing approach?
- What problem is it trying to solve?
- What does everyone in this space assume to be true?
Step 2: Challenge Every Assumption
For each element of the current approach, ask:
- "Is this actually true, or do we believe it because we've always believed it?"
- "Is this a constraint of reality, or a constraint of convention?"
- "What would have to be true for this assumption to be wrong?"
More from andurilcode/skills
causal-inference
Apply causal inference whenever the user is interpreting metrics, debugging system behavior, reading A/B test results, or trying to understand whether an observed change was caused by an action or by something else. Triggers on phrases like "X caused Y", "since we deployed this, metrics changed", "the A/B test showed a lift", "why did this metric move?", "is this correlation or causation?", "we changed X and Y improved", "how do we know this worked?", "the data shows…", or any situation where conclusions are being drawn from observational data. Also trigger before any decision based on metric interpretation — confusing correlation with causation leads to interventions that don't work and misattribution of credit. Never assume causation without applying this skill.
31probabilistic-thinking
Apply probabilistic and Bayesian thinking whenever the user needs to reason under uncertainty, compare risks, prioritize between options, update beliefs based on new evidence, or make decisions without complete information. Triggers on phrases like "what are the odds?", "how likely is this?", "should I be worried about X?", "which risk is bigger?", "does this data change anything?", "is this a signal or noise?", "what's the probability?", "how confident are we?", or any situation where decisions are being made based on incomplete or ambiguous evidence. Also trigger when someone is treating uncertain outcomes as certainties, or when probability language is being used loosely ("probably", "unlikely", "very likely") without quantification. Don't leave uncertainty unexamined.
28inversion-premortem
Apply inversion and pre-mortem thinking whenever the user asks to evaluate a plan, strategy, architecture, feature, or decision before execution — or when they want to stress-test something that already exists. Triggers on phrases like "is this a good idea?", "what could go wrong?", "review this plan", "should we do this?", "are we missing anything?", "stress-test this", "what are the risks?", or any request to validate a decision or design. Use this skill proactively — if the user is about to commit to something, this skill should be consulted even if they don't ask for it explicitly.
24cognitive-bias-detection
Apply cognitive bias detection whenever the user (or Claude itself) is making an evaluation, recommendation, or decision that could be silently distorted by systematic thinking errors. Triggers on phrases like "I'm pretty sure", "obviously", "everyone agrees", "we already invested so much", "this has always worked", "just one more try", "I knew it", "the data confirms what we thought", "we can't go back now", or when analysis feels suspiciously aligned with what someone wanted to hear. Also trigger proactively when evaluating high-stakes decisions, plans with significant sunk costs, or conclusions that conveniently support the evaluator's existing position. The goal is not to paralyze — it's to flag where reasoning may be compromised so it can be corrected.
24analogical-thinking
Apply analogical thinking whenever the user is designing a system, architecture, or process and would benefit from structural patterns that already exist in other domains — or when a problem feels novel but may have been solved elsewhere under a different name. Triggers on phrases like "how should we structure this?", "has anyone solved this before?", "we're designing from scratch", "what's a good model for this?", "I keep feeling like this resembles something", "what patterns apply here?", or when facing architecture, organizational, or process design decisions. Also trigger when a problem has been analyzed thoroughly but no good solution has emerged — the answer may exist in an adjacent domain. Don't reinvent what's been solved. Recognize the shape of the problem first.
23scenario-planning
Apply scenario planning whenever the user is making long-term decisions, building roadmaps, evaluating strategies, or operating in an environment with significant uncertainty about how the future will unfold. Triggers on phrases like "what should our roadmap look like?", "how do we plan for the future?", "what if things change?", "we're not sure which direction the market will go", "how do we make this strategy resilient?", "what's our plan B?", "what are the different futures we could face?", or when a plan assumes a single future state. Also trigger when someone is over-committed to one expected outcome and hasn't stress-tested the strategy against alternative futures. Don't plan for one future — plan for multiple.
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